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vcnanuRkm CIvviTüa Gg;eKøs-Exµr

Biology Dictionary English - Khmer

saklviTüal½yPUminÞPñMeBj ed)a:tWm:g; CIvviTüa e)aHBum

Preface to the Third Edition (Revised) This dictionary is the work of many teachers and some students in the department of The Royal University of Phnom Penh. It has developed over the last three years in response to the need of Biology students to learn Biology from English text books. We have also tried to anticipate the future needs of Biology students and teachers in Cambodia. If they want to join the global scientific community; read scientific journals, listen to international media, attend international conferences or study outside Cambodia, then they will probably need to communicate in English. Therefore, the main aim of this book is to help Cambodian students and teachers at the university level to understand Biology in English. All languages evolve. In the past the main influence on Khmer language was French. Nowadays, it is increasingly English. Some technical terms have already been absorbed from French and have become Khmer. Nowadays new technical terms are usually created in English and are used around the world. Language is also created by those who use it and only exists when it is used. Therefore, common usage has also influenced our translation. We have tried to respond to these various influences when preparing this dictionary, so that it represents many different opinions - old and new, Francophile, Anglophile and Khmer. But there will always be some disagreement about the translation of some terms. This is normal and occurs in all languages. It is a healthy sign of a language that is actively growing. Since understanding Biology in English is the main aim of this dictionary, we have tried to use English that is suitable for second language speakers, and Khmer words whose meaning is easy to understand. For those words that are new to the English language, and could not be easily translated into Khmer, we have given Khmer spelling that will help with pronunciation. But we must remember that: the definitions of words can change over eg. Mongolism is now Down’s Syndrome or Trisomy 21; there is sometimes more than one correct definition eg. wetland has a wide range of meaning ; and, different spellings can be correct eg feces = faeces. This book is an attempt to represent a consensus of current usage, but further change is inevitable. We hope that this book will become a useful reference for Cambodian students and teachers and assist them in accessing the wealth of information about Biology that is available in English. David Ford Advisor to Biology Department The Royal University of Phnom Penh 2002

Acknowledgements Many thanks to the following people for their hard work: Hap Sophorn (translation and editing), Hang Chan Thon (translation and editing), Men Noeun (translation), Khieng Sothy (translation). Also thanks to the following people for their assistance in specific subject areas: Thai Ieng Ly (), Thou Phorn (), Ke Kuntheamealea (), Kop Sokhom (vertebrates), and Kauv Samnang (invertebrates). Also thanks to Mr Peter Leth for his help in sorting the Khmer – English section. Finally, this book would not have been produced without the assistance of the NGOs Australian Volunteers International and MaryKnoll.

GarmÖkfasMrab;kare)aHBum

eyIgsgÇwmy:agmutmaMfa esovePAenHnwgkøayeTACaÉksard¾manRbeyaCn_mYysMrab;nisSit nig saRsaþcarükm<úCa ehIynwgCYyBYkeKeGayTTYl)annUvBt’mand¾sMbUrEbbGMBICIvviTüaCaPasaGg;eKøs.

David Ford TIRbwkSakñúged)a:tWm:g;CIvviTüa saklviTüal½yPUminÞPñMeBj2002 esckþIEføgGMNrKuN sUmEføgGMNrKuNy:agRCaleRCAdl;GñkEdl)ancUlrYmkñúgkargard¾lM)akenH ³ hab esaP½N ¬bkERb nigEksMrYl ¦ hg; can;fun ¬bkERb nigEksMrYl ¦ Em:n enOn ¬bkERb ¦ nig eXog suFI ¬bkERb¦ . sUmEføgGMNrKuNpgEdr cMeBaHGñkEdl)ancUlrYmBiPakSanUvBaküTaMg- LayEdlmanTMnak;TMngnwgCMnajrbs;BYkeK³ éf eGogl I ¬kayviPaKviTüa ¦ FU Pn ¬esenTic ¦ k> Ek Kn§mala ¬KImICIv³¦ xub suxum ¬stVq¥wgkg ¦ nig k>kUv sMNag ¬stV\tq¥wgkg¦. sUm EføgGMNrKuNpgEdrcMeBaHelak Peter Leth Edl)anCYyeróbcMdak;tamlMdab;nUvEpñkExµr- Gg;ekøs. CacugbBa©b; esovePAenHminGacerobcMeLIg)aneT ebIKµanCMnYyBIGgÁkarGñksµ½KcitþGURsaþlI nigm:arINulEdlCaGgÁkareRkArdæaPi)al.

A A Horizon : (Topsoil) The uppermost layer of soil, usually RsTab;elI ³ ¬dIxagelI ¦ RsTab;elIbMputrbs;dI EdlCaTUeTAmankMras; about 10 to 20 cm. thick. BI 10 eTA 20 s>m. ABA see abscisic acid. ABA : emIl abscisic acid . abaxial : Away from the axis cakGk½S ³ Edlcakecjq¶ayBIG½kS. abdomen : 1. The body region 1 posterior to the thorax of eBaH ³ - cMeBaHGakRtUb:Ut CaEpñkéndgxøÜnEdlsßitenAxageRkayRTUg arthropods. 2. A region in 2 vertebrates between the thorax and - cMeBaHstVq¥wgkg CaEpñksßitenAcenøaHRTUgnigRtKak nigmansrIragÁ pelvis containing many organs. enAxagkñúgCaeRcIn. abduction : Movement away from the midventral axis of the body. Gab;Ducsüúg ³ clnaecjBIG½kSkNþaleBaHénsarBagÁkay. See also adduction . sUmemIl adduction . : The old idea that living things can grow directly kMeNItekItÉg ³ KMnitbUraNEdlGHGagfaPavrs;GacekIteLIgpÞal;BI from non-living material; spontaneous generation. rUbFatuKµanCIvit³karkekItedayÉkÉg. abiotic factor : Describes a factor ; that is not, and has never been ktþaKµanCIvit ³ BN’‘naBIktþaKµanCIvit nigminEdlmanCIvit kMlaMgrW living; the physical and non-living materials or forces that influence rUbFatuKµanCIvitEdlCH\Ti§BleTAelIPavrs;. . ABO blood group : A ABO classification of human blood RkumQam ³ CacMNat;fñak; RbePTQamrbs;mnusS. manbYn types. There are four groups: A, B, A, B, AB O AB and O, each classified by a RkumKW ³ nig EdlRkumnImYy² RtUv)ancat;fñak;eday particular combination of antigens bnSMénGg;TIEsnenAelIeKalikaRkhm ¬emIl H-substance ¦ nigGg;TIk on the red blood cells (see H- substance ) and naturally occurring EdlekIteLIgBIFmµCatienAkñúg)øasaµQam. Gg;TIEsn nigGg;TIkénRbePT antibodies in the blood plasma. Antigens and antibodies of the dUcKñanigCab;KñaenAeBllaycUlKña EdlbNþaleGaymankarBi)akkñúg same type cause agglutination universal donors and universal recipients when mixed, resulting in karbBa©ÚlQam ¬emIl ¦. difficulties in blood transfusion tMNBUCénRkumQam RtUv)anRtYtBinitüeday EsnGUtUsUmmYy ¬emIl (see universal donors and universal recipients ). Inheritance autosome ¦enAelIRkUm:UsUmTI9 Edlman GaELlbIsMxan;² KW A, B nig of blood grouping is controlled by A B o a single autosomal gene (see O ¬CYnkalsresrCa I , I nig I ¦. autosome ) on 9 with three main alleles, A, B and O (sometimes written as I A, I B and 1O). aboral : A region opposite the mouth. bdimat; ³ EpñkpÞúyBImat;. abortive transduction : An event ADN ADN in which transducing DNA fails to bBa¢Ún minsMerc ³ ehtukarN_énkarbBa¢Ún cUleTAkñúgRkUmU:sUm be incorporated into the recipient transduction chromosome. See transduction. GñkTTYlmin)ansMerc. emIl .

abscisic acid (ABA) : A hormone (growth regulator) GasIutGabsIusuic ³ Grm:UnrukçCati ¬niy½tkrkarlUtlas; ¦ Edl associated with water stress and the inhibition of growth; also induces Tak;TgnwgkarxVHCatiTwk nigkarbg¥ak;énkarlUtlas; ehIyk¾bNþal stomatal closing and seed eGaymankarbiTsþÚm:at nigPaBminlUtlas;rbs;RKab; enAkúñgrukçCati dormancy in many . CaeRcIn. abscission : The separation of a leaf, flower, seed or fruit from a karRCúH ³ kardac;Føak;énsøwk páa Epø rWRKab;ecjBIEmk b¤edImrbs;va. stem. abscission layer : The thin layer of cells at the base of the petiole RsTab;pþac;Tg ³ RsTab;ekasikaesþIgmYyRsTab;enAKl;TgEdlkekIt that forms at the end of the growing season and causes eLIgenAcugrdUvlUtlas; nigbNþaleGaymankarRCuH ¬søwk EpøCaedIm ¦. abscission to occur. absolute zero : Temperature at which all molecular motion tMélsUnüdac;xat ³ maRtdæankMedAénsItuNðPaBEdlm:UelKulKµanclna theoretically stops, measured as -273.15 oC 0 K -273.15 oC or 0 K. ebIKittamRTwsþI ehIyvaRtÚv)anvas;eday b¤ . absorption : The process by which substances such as food and karRsÚb rWsMrUb ³ dMeNIrEdlsarFatu dUcCacMNIGahar GuksIuEsn oxygen pass through a body membrane. qøgkat;PñasénsarBagÁkay. absorption spectrum : The spectrum of light absorbed by a s,úicsMrUb ³ s,úicBnøWEdl®tUv)anRsUbedayCatiBN’NamYy. particular pigment abyssal zone : The deepest part of the , with depth generally tMbn;smuRTeRCA ³ tMbn;smuRTeRCAbMputEdlBnøWminGaccUleTAdl; Ca greater than 1000 metres, where light does not reach. TUeTAmanCMerACag 1000 Em:Rt. accessory pigment : A pigment that captures light and CatiBN’bnÞab;bnSM ³ CatiBN’mYyEdlcab;ykfamBlBnøW nigpøas;bþÚr transfers it to chlorophyll a; a β beta-carotene is an example of an vaeTACakør:UPIl . ]TahrN_ ³ kar:UEtn. accessory pigment. accessory structures : The parts of some flowers that are not TMrg;bnÞab;bnSM ³ EpñkTaMgLayrbs;páamYycMnYnEdlminrYmcMENkpÞal; directly involved in gamete production. kñúgkMNkaEm:t. accommodation : The process by which the eye focuses on objects at sMrbtMrUv ³ dMeNIrEdlEPñkRbwgemIleTAvtßúcMgayxus²Kña. cMeBaHRtI nig different distances. In fish and amphibians the lens is moved GMbUrkEgábEkvEPñkGaceFVIclnaeTAeRkay nigeTA mux bu:EnþcMeBaHbkSI / backwards and forwards, but in lµÚn nigmnusS ragrbs;EkvEPñkpøas;bþÚredaysarsac;duMEkvEPñk. birds, reptiles and humans the shape of the lens is changed by the ciliary muscles. accuracy : How close the measured value is to the true value. PaBc,as;las; ³ tMélrgVas;EdlCittMélBitCageK. acentric chromosome : Chromosome or chromosome frag- RkUmU:sUmGasg;RTic ³ RkUmU:sUm b¤bMENkRkUmU:sUmEdlKµansg;RtUEm. ment with no . acetabulum : Depression on the pelvic girdle that accommodates Gaestabu‘ylum ³ kMhUgq¥wgRtKakEdlRtÚvnwgk,alq¥wgePøA. the head of the femur.

acetic acid : A carbon compound ³ smasFatukabUn manrUbmnþ CH 3COOH EdlGac with the formula CH 3COOH that GasuItGaesTic can be produced from the breakdown of pyruvic acid before RtUv)anbegáItBIkarbMEbkénGasIutBIruyvic munvdþGasIutsIuRTic. the citric acid cycle. acetyl : The 2-carbon remainder of the carbon skeleton of pyruvic acid GaesTIl ³ sMNl;kabUn-2 éneRKagkabUnrbs;GasIutBIruyvic Edl that is able to enter the mitochondrion. GaccUleTAkñúgmItUkugRTI)an. acetyl CoA : A coenzyme with the A : kUGg;sIummanrUbmnþ C23 H39 O17 N7P3SEdlRtUv)an formula C 23 H39 O17 N7P3S that is GaesTIlkUGg;sIum formed when acetic acid reacts A with coenzyme A at the start of the begáIteLIgenAeBlEdlGasIutGaesTiceFVIRbtikmµCamYykUGg;sIum enA citric acid cycle. edImvdþGasIutsuIRTic. acetylcholine : A compound with C 7H17 O3N the formula C 7H17 O3N that GaesTIlkUlIn ³ smasFatumanrUbmnþ Edlmanmuxgarkñúg functions in the transmission of nerve impulses. karbB¢ÚanrMejacRbsaT. acetylcholinesterase : An enzyme that blocks the function of GaesTIlkUlIeNsEsÞr:as ³ Gg;sIumEdlbg¥ak;muxgarrbs;Gaes- acetylcholine. TIlkUlIn. achene : A dry fruit with a seed enclosed in a thin hard layer EpøsMbkrwg¬rWGaEkn¦³EpøeQIs¶ÜtEdlRKab;sißtenAkñúgRsTab;sMbkesþIg formed from the ovary wall. rwgekIteLIgBIPñasGUEv ¬QUk/GgÁúj ¦. acid : Hydrogen ion donor; a molecule or ion that ionizes to give GasIut ³ GñkeGayGIuy:ugGIuRdÚEsn ¬RbÚtug ¦Cam:UelKul rW CaGIuy:ug up one or more hydrogen ions; a substance that releases hydrogen EdlbMEbkCaGIuy:ugedIm,Ipþl;RbÚtugmYy rWeRcIn. sarFatuEdlbeBa©j ions when mixed with water. GIuy:ugGIuRdUEsnenAeBllayCamYyTwk. acid anhydride : Derivative of an organic acid that is dehydrated, GanIRDItGasIut ³ RsLayrbs;GasIutsrIragÁEdlTTYlrg having the structure O O O O edsIuRdatkmµehIymanTMrg;Ca R C O C R R C O C R acid equilibrium constant (K a): Equilibrium constant for a weak efrlMnwgGasIut ³ efrlMnwgsMrab;GasIutexSaymYy EdlCabnSMén acid, which is a combination of the Ka = [H 20] K eq water concentration (considered to kMhab;Twk ¬cat;Tukfaefr ¦nigefrlMnwg . be constant) and the equilibrium constant. K a = [H 20] K eq acid : A type of pollution caused by the combination of ePøógGasIut ³ RbePTsarFatukxVk;EdlbNþalmkBIbnSMéns

acidosis : Condition that exists pH whenever the blood pH drops PaBGasIut ³ l½kçx½NÐEdlekIteLIgenAeBlEdl rbs;Qam below the normal range; can be metabolic or respiratory in origin. Føak;cuHeRkamkMritFmµta ehIyGacbNþalmkBIbNþÚrrUbFaturWkardkdegðIm kñúgsarBagÁkay. acipenser : A genus of sturgeon sturgeon fish. GasIub:g;es ³ eQµaHBYkénRtIq¥wgx©I . acoelomate : Without a coelom. Lacking a body cavity between the KµansWLÚm ³ KµanRbehagsWLÚm. KµanRbehagxøÜnrvagbMBg;rMlayGahar gut and the outer body wall musculature. The internal organs nigépÞsac;dMuxageRkAénxøÜn. srIragÁxagkñúgsßitenACab;²Kña. are closely packed together. acquired characteristics : Features that an develops lkçN³sMrbtMrUv ³ lkçN³TaMgLayrbs;Pavrs;EdlERbRbYlrWbgáeLIg during its lifetime. kñúgkMLúgeBlrs;enArbs;va. acquired immunodeficiency syndrome (AIDS) : An infectious eGds_ ³ CaCMgWqøg bNþalmkBIRbtivIrus ehAfa vIrusEdlbMpøaj disease caused by a retrovirus HIV called the human immuno- PaBsaMurbs;mnusS ¬ ¦. CMgWenHRtUv)ansMKal;lkçN³edaykar deficiency (HIV). The bMpøaj T-LaMpUsuItrbs;RbBn§½sauMbnþicmþg² / RKunCaerOy² / kar)at;bg; disease is characterized by a gradual depletion of T TMgn; / karqøgCMgWekIneTVeLIg / ehIymanCMgWrlaksYt nigmharIk rYmCa lymphocytes, recurring fever, weight loss, multiple opportunistic mYynUvkarcuHexSayénRbBn§½PaBsaMu. infections, and rare forms of pneumonia and cancer associated with collapse of the immune system. acrocentric chromosome : Chromosome with the centromere RkUmU:sUmGaRkUsg;RTic ³ CaRkUmU:sUmEdlsg;RtUEmmanTItaMgenACitcug located very close to one end. Human 13, 14, 15, bMputénédmçag. RkUmU:sUmmnusSTI 13 / 14 / 15 / 21 / nig 22 21, and 22 are acrocentric. CaGaRkUsg;RTic. acropetal : Toward the apex. basipetal Compare basipetal. GaRkUeb:tal ³ eq

active immunity : Immunity gained by direct exposure to PaBsuaMskmµ ³ PaBsuaMEdlTTYl)anedaykardak;b:HpÞal;eTAnwg antigens followed by antibody production. Gg;TIEsn ehIybnÞab;mkmankarbegáItGg;TIk. active site : Site on an enzyme where the substrate bonds and the mNÐlskmµ ³ mNÐlenAelIGg;sIumEdlsm<½n§s‘ubRsþargRbtikmµ reaction is catalyzed. énkatalIkr. active transport : Movement of solutes across a membrane from dMNwknaMskmµ ³ clnasarFaturlayqøgkat;PñasmYy BIkEnøgEdl low to high concentration; active transport requires energy from mankMhab;TabeTAx

A coenzyme compound made of GaedNUsIunDIpUsVat ³ smasFatukUGg;sIumEdlRtUv)anbegáIteLIgBI adenine, ribose and two molecules of phosphoric acid that can be GaednIn-rIbUs nigGasIutpUsVricBIrm:UelKul EdlGacRtUv)anbMElgeTACa converted into ATP. ATP . adenosine triphosphate (ATP) : A consisting of adenine, GaedNUsIunRTIpUsVat ³ nuyekøGUTItmYyEdlrYmman GaednIn-sárrIbYs ribose, and three phosphate groups; the major source of usable nigRkumpUsVr3. vaCaRbPBfamBlKImId¾sMxan; EdlGaceRbIR)as;)an chemical energy in metabolism; enAkúñgemtabUlIs. enAeBlEdleFVIGIuRdUlIs ATP )at;bg;pUsVrmYy edIm,I when hydrolyzed, ATP loses a phosphate to become adenosine køayeTACaGaedNUsuInDIpUsVat (ADP) nigpþl;nUvfamBlEdlGac diphosphate (ADP) and releases usable energy. eRbIR)as;)an.

adenovirus 2 : A type of virus that 2 causes human respiratory disease; GaedNUvIrus ³ vIrusmYyRbePTEdleFVIeGayRbB½n§degðImmnusSman its role in genetic research involved the discovery of introns. CMgW. tYnaTIrbs;vakñúgkarRsavRCavesenTic Tak;TgnwgrbkKMehIjén GaMgRtug. adhesion : An attraction between unlike molecules due to CMnab;s¥it ³ TMnajrvagm:UelKulxusKñaGaRs½yedaykMlaMgGnþr intermolecular forces. m:UelKul. adipose tissue : Connective tissue specialised to store fat. Calikaxøaj; ³ Calikasn§anEdlmannaTIkñúgkarsþúkxøaj;. A-DNA : An alternate form of the ADN A AND right-handed double helical --- ³³³ CaragmYyénTMrg;regVleTVédsþaMén EdlregVlenaHman structure of DNA in which the karGgÁÜjxøaMgCag ehIyman 11KU)askñúgmYyregVleTV b¤kñúgmYyCMhan. helix is more tightly coiled, with 11 base pairs per full turn of the helix. adrenal gland : An endocrine gland located above the kidney that RkeBjelItMrgenam ³ RkeBjbeB©ajkñúgEdlsßitenAelItMrgenam secretes corticoid hormones and adrenaline. nigbeB©ajGrm:UnK½rTIkUGIut nigGaeRdNalIn. adrenaline : A hormone secreted by the adrenal medulla that acts to GaeRdNalIn ³ Grm:UnEdlbeB©ajedayEpñkkNþalénRkeBjelItMrg increase blood pressure by stimulating heart action and enam nigmanmuxgarbegáInsMBaFQamedayePJacclnaebHdUg nigbRgYm constriction of some blood vessels; srésQammYycMnYn . eKehAvafaeGBIenRhVInpgEdr. also called epinephrine. adventitious root : Any root that grows from a part of the plant that rwsRBeyag ³ rwsEdlduHecjBIEpñkNamYyénrukçCatiEdlminEmnCarws is not the primary root. sMxan;. aerenchyma : A tissue containing large amounts of intercellular Gar:g;sIum ³ CalikamancenøaHGnþrekasikaeRcIn. . aerial respiration : In organisms, ³ bNþÚr]sµ½nGuksIuEsn nig]sµ½nkabUnicBIxül;én exchange of oxygen and CO 2 from dMNkdegðImelIeKak the air. Usually internal (mesophyll of leaves, vertebrate lungs), but can Pavrs;elIeKak. CaTUeTAbNþÚr]sµ½nenHRbRBwtþeTAenAemsUPIlénsøwk be external (skin of amphibia). rukçCatinigsYtstVq¥wgkg b:uEnþk¾GacRbRBwtþeTAenAxageRkApgEdr ¬Es,k GMbUrkEgáb ¦. aerobic : Needing oxygen. manxül; rWRtUvkarxül; ³ tMrUvkarGuksIuEsn. aerobic cellular respiration : The biochemical pathway that degðImekasikamanxül; ³ dMeNIrKImICIv³EdlRtUvkarGuksIuEsn nig requires oxygen and converts food, such as carbohydrates, to carbon bMElgGahardUcCaKøúysIuteGayeTACa]sµ½nkabUnicnigTwk. enAeBl dioxide and water. During this bMElgenHvabeBa©jfamBlsm<½n§KImI CamU:elKul ATP . conversion, it releases the chemical-bond energy as ATP molecules. aestivation : A period of inactivity and reduced metabolism during CIvitRkaMg ³ ry³eBlEdlKµanskmµPaB nigemtabUlIsfycuHenA summer. rdUvR)aMg. afferent : A structure (blood vessel, nerve, etc.) leading toward cUl ³ TMrg; ¬srésQam / srésRbsaT ¦naMcUleTAcMNucNamYy. some point.

agar : A material found in red algae that is used in laboratories to Gaháa ³ sarFatumanenAkñúgsarayRkhm EdlRtUv)anykmkeRbIenA grow and fungi. kñúgmnÞIrBiesaF_¾ edIm,IbNþúH)ak;etrInigpSit. age distribution : The number of organisms of each age in the r)ayGayu ³ cMnYnPavrs;énGayunImYy² kñúgb:UBuyLasüúg. population. agglutination : The joining together of an antigen and an CMnab;Kña ³ karP¢ab;KñarvagGg;TIEsnnigGg;TIkr. antibody. aggregate fruit : A type of fruit that develops from many different EpøRbmuM ³RbePTEpørukçCatiEdllUtlas;BIGUEvepSg²KñaCaeRcInenAkñúg ovaries in a single flower. eg. Blackberry, rasberry Blackberry, rasberry. páaEtmYy. ]TahrN_³ . aggressive behavior : Dominant or fighting behavior. e.g. a dog Gakb,kiriyaQøanBan ³ Gakb,kiriyalubelIeK b¤vayRbharelIeK . defending its territory. ]TahrN_³ EqáEdlecHEtRBusenAeBllWsMribmnusSedIr b¤eXIjstVepSg eTotedIrkat;tMbn;rbs;va. agnatha : A class of vertebrates Mixinoidea that includes the modern lampreys KµanfÁam ³ fñak;stVq¥wgkgmYy EdlrYmmanLMRB½r nig and hagfish and the extinct Ostracoderms ostracoderms. Edlrlt;putBUC. air sac : An organ of gas exchange that opens off the trachea in insects fg;xül; ³ srIragÁbNþÚr]sµ½nEdlebIkcMhredaybMBg;xül; cMeBaH and birds. stVl¥it nigbkSI. akinete : A thick-walled dormant cell derived from a vegetative cell. GaKIENt ³ ekasikaRkaMgmanPñasRkas; EdlmanRbPBBIekasika rukçCati. albinism : A condition caused by the lack of melanin production in ePOk ³ sßanPaBEdlbNþalmkBIkar)at;bg;karplitsarFatuemLanIn the iris, hair, and skin. In humans, most often inherited as an kñúgRbRsIEPñk / sk; / nigEs,k. cMeBaHmnusSPaKeRcInCatMnBUCkMnt; autosomal recessive trait. edayEsnGn;enAelIGUtUsUm. albumen : The white part of an egg. A substance rich in protein Gal;b‘uymIn ³ Epñksrbs;s‘ut. sarFatusMbUrRbUetGIun EdlenAB½T§CuMvij surrounding the yolk in a bird’s egg. s‘utelOgkñúgs‘utbkSI. albumin: A group of proteins, soluble in water or dilute salt Gal;b‘uyEmn ³RkumRbUetGIunrlaykñúgTwknigsUluysüúgGMbil EdlRbT³ solution that are found in and some plants. eXIjcMeBaHstVnigrukçCatimYycMnYn. albuminous cell: Certain ray and axial parenchyma cells in the ekasikaGal;b‘uyEmn ³ ekasika)a:r:g;suIménG½kS nigkaM enAkñúgpøÚEGm phloem of gymnosperms; these cells are closely associated with rbs;rukçCatisuImNUEs

alcoholism : When someone is physically and psychologically ejonRsa ³ enAeBlmnusSmñak;BwgBak;RsaTaMgkay TaMgcitþ. dependent on alcohol. aldehyde : Family of organic compounds formed when an alkyl Gal;edGIut ³ GMbUrsmasFatusrIragÁEdlekItmanenAeBlRkúmGal;KIl group is placed on one of the carbon bonds of a carbonyl group RtÚvP¢ab;eTAnwgsm<½n§mYyrbs;kabUnénRkumkabUnIl nigGIuRdÚEsnmYyRtUv and a hydrogen is placed on the )anP¢ab;eTAsmç½n§kabUnmYyepSgeTot. TMrg;TUeTAKW ³ other. The general structure is O O O O C C Ar C H R C H Ar H R H

The carbonyl group is always on a RkúmkabUnIlCanic©kalenAelIGatUmkabUncugeRkaybMput. terminal carbon atom. aldose : Monosaccharide ald- containing an aldehyde group. The Gal;dUs ³ m:UNUsak;karItEdlmanbgÁúMGal;edGIut . buBVbT prefix ald- indicates the presence –ose of an aldehyde group, and the –ose bBa¢ak;BIvtþmanrbs;RkúmGal;edGIut nigbc©½y bBa¢ak;BIkabUGIuRdat. suffix indicates a carbohydrate. aleurone layer : A layer of protein-rich cells located at the RsTab;GaLWr:Un ³ RsTab;ekasikaEdlsMbUreTAedayRbUetGuIn Edlzit outer edge of the endosperm of many grains, which contains enACayxageRkAénGg;dUUEs

alkaptonuria : An autosomal recessive condition in humans Gal;xab;fUNYero ³ cMeBaHmnusSCasßanPaBGUtUsUmGn; bNþalmkBI caused by the lack of an enzyme, homogentisic acid oxidase. Urine kgVHGg;suImGasIutGUmU:EsnTIsiucGuksuIdas. Twkenamrbs;Éktþ³ GUmU:suIkUt of homozygous individuals turns ERbCaBN’Rkem:AbnÞab; RTaMRTnwg GuksuItkmµGasuItGUmU:EsnTIsiucEdl dark upon standing due to oxidation of excreted homogentisic beBa©jecal. q¥wgx©Irbs;mnusSeBjvy½GUmU:suIkUtERbCaBN’exµAeday acid. The cartilage of homozygous adults blackens from deposition of kMNkCatiBN’EdlmanRbPBBIGasuItGUmU:EsnTIsuic. mnusSTaMgenH eRcIn a pigment derived from homogentisic acid. Such EtekItnUvCMgWsnøak;éd b¤eCIg. individuals often develop arthritis. alkene : Family of hydrocarbon compounds having at least one Gal;Esn ³ GMbUrénsmasFatuGIuRdÚkabYEdlmansm<½n§BIrCan;y:agtic double bond between carbon atoms mYyrvagGatUmkabUnkñúgeRKagm:UelKul CnH2n . in the molecular skeleton. C nH2n alkyl group : Hydrocarbon group made up of a hydrocarbon minus RkúmGal;KIl ³ RkúmGIuRdÚkabYEdlRtÚvdkGatUmGIuRdÚEsnmYyecj. one of its hydrogen atoms. This -ane -yl group is named from the parent RkúmenHeGayeQµaHecjBIGal;kanExSem edaykarCMnYs eday . alkane by replacing the –ane end- RkúmGal;KIlRtÚvtagedaynimitþsBaaØ R . ing with –yl. Alkyl groups are often represented by the symbol R. alkyne : Family of hydrocarbon compounds having at least one Gal;sIun ³ GMbUrénsmasFatuGIuRdÚkabYEdlmansm<½n§bICan;y:agtic triple bond between carbon atoms mYyrvagGatUmkabUnkñúgeRKagm:UelKul CnH2n-2. in the molecular skeleton. C nH2n-2 allantois : A membrane around the outside of the embryo that helps in GaLg;tUGIut ³ PñasCuMvijGMRb‘Íy:ugEdlr:ab;rgkardkdegðIm nigkar respiration and excretion for embryos of birds, reptiles and some beB©ajecal cMeBaHGMRb‘Íy:ugbkSI lµÚn nigfnikstVmYycMnYn. mammals. One of the extra PñasGMRb‘Íyu:gmYyRsTab;éneRsamTwkePøaH. embryonic membranes of the amniotes. allele frequency : A term used to describe how common a specific eRbkg;GaELl ³ BaküeRbIsMrab;erobrab;BIkarekIteLIgénGaELl allele is compared to other alleles for the same characteristic. See yfaRbePTedayeRbobeFobeTAnwgGaELlepSg²eToténlkçN³dUcKña. gene frequency. cUremIleRbkg;Esn. alleles : Different forms of a gene that code for slightly different GaELl ³ TMrg;xusKñaénEsnEdlcMlgRkm sMrab;lkçN³xusKñabnþic traits. bnþÜc. allelic exclusion : The selective action of only one allele in plasma CMerIsGaELl ³ kareRCIserIsénGaELlEtmYy kñúgekasika)aøsµa Edl cells that are heterozygous for an immunoglobulin gene. CaeGetrU:suIkUt cMeBaHEsnkMnt;PaBsaMueKalikatUc. allochthonous : With an origin somewhere other than the region BIkEnøgepSg² ³ EdlmanRbPBenAkEnøgepSgBIkEnøgEdleKCYb where found. RbTH. allopatric : Occurring in different places. tamtMbn;xus²Kña ³ EdlekIteLIgenAkEnøgepSg²Kña. allopatric speciation : Speciation induced by geographical or kMNRbePTtamtMbn;xus²Kña ³ kMNRbePTedaybMENgEckrUb physical separation of the ancestral population. rWPUmisaRsþénb:UBuyLasüúgedIm.

allopatry : Situation in which two or more populations or species GaLÚ)a:RTI ³ sßanPaBEdlb:UBuyLasüúgrWRbePTBIr rWeRcInrs;enAkñúgtMbn; occupy different geographic ranges that can be next to each PUmisaRsþepSgKña nigGacenACitKña. other. allopolyploid : A polyploid with multiple sets of chromosomes that GaLÚb:UlIbøÚGIut ³ b:UlIbøÚGuItEdlmanRkUm:UsUmCaeRcInRkum manRbPBBI originated from more than one species. RbePTeRcIn. allosteric regulation : Regulation that results from a change in the tMrUvGaLÚesþric ³ tMrUvbNþalmkBIkarpøas;bþÚrrUbragénRbUetGIunEdlekIt shape of a protein that occurs when the protein binds a nonsubstrate eLIgenAeBlRbUetGuInenaHP¢ab;CamYym:UelKulminEmns‘ub®sþa. kúñgTMrg;fµI molecule; in its new shape, the rbs;va RbUetGuInmanlkçN³epSgKña. tMrUvskmµPaBGg;sIumedayCMnab; protein usually has different properties; regulation of enzyme m:UelKultUc²eTAkEnøgepSgBIkEnøgskmµ. activity by the binding of small molecules to sites other than the active site. allotetraploid : Diploid for two derived from different GaLÚetRtabøÚGuIt ³ DIbøÚGuItsMrab;esNUmBIrEdlmanRbPBBIRbePT species. epSg²Kña. allozymes : Enzymes that are copied from different alleles of the GaLÚsIum ³ Gg;suImEdlRtUv)ancMlgBIGaEllepSg²KñaénLÚKus same locus; each form is encoded locus by different alleles. ¬ ¦dUcKña. TMrg;nimYy²RtÚv)ancMlgedayGaEllepSg²Kña. alpha ( ααα ) helix : Secondary structure of a protein in which the eGlIsGal;hVa ³ TMrg;TIBIrénRbÚetGIunEdlkñúgenaHeRKagRcvak; polypeptide backbone is arranged into a regular spiral shape. b:UlIbiubTItRtÚv)anerobCarages<ór. alpha ( ααα) particles : Relatively heavy having the mass of PaKli¥tGal;hVa ³ PaKli¥tF¶n;manm:as;GatUmGIuRdÚEsnbYn EdlpÞúk four hydrogen atoms that carry two bnÞúkviC¢manBIrehIyEdlRtÚv)an)aj;ecjBIGatUmviTüúskmµmYycMnYn. positive charges and are fired out of some radioactive atoms. alpha decay : Radioactive decay involving emission of an alpha karbMEbkGal;hVa ³ karbMEbkviTüúskmµedaykarsayecjénPaKli¥t . The daughter product of α α alpha decay has two fewer protons . plitplkUn ¬plitplrg ¦ énkarbMEbk manRbÚtugnigNWRtúgBIr and two fewer neutrons than the ticCagGIusUtUbem ¬GIusUtUbedIm ¦. parent isotope. alpha fetoprotein (AFP) : A kd 70-kd glycoprotein synthesized in eptURbUetGuInGal;hVa ³ KøIkURbUetGuInEdlmanTMgn; 70 EdlRtUv embryonic development by the yolk sac. High levels of this protein )ansMeyaKkñúgkarlUtlas;GMRb‘Íyu:gedayfg;GgÁelOg. kMritx

alpha-ketoglutarate (alpha- ketoglutaric acid) : A five- carbon GasIutXItUKøúytaricGal;hVa ³ GasuItsrIragÁmankabUn 5 Edl)at;bg; organic acid that loses a molecule –CoA of carbon dioxide and gains an ]sµ½nkabUnicmYym:UelKul nigcMeNjRkumGaesTIl enAvKÁTI4én acetyl-CoA group in the fourth step vdþERkb edaypøas;bþÚreTACa succinyl-CoA . kñúgeBlpøas;bþÚrenH of the Krebs cycle, thereby being + converted to succinyl-CoA; also m:UelKulmYyén NAD ®tUv)anbnßyeTACa NADH . during this conversion, one molecule of NAD + is reduced to NADH. alpha-tubulin : A type of globular protein that is a main component of TUb‘UlInGal;hVa ³ RKab;RbUetGuIntUc²mYyRbePT EdlCaFatubgá microtubules. mYyd¾sMxan;rbs;kUnbMBg;. alternation of generations : A cycle of certain plants and animals karqøas;CMnan; ³ vdþCIvitrbs;rukçCatinigstVmYycMnYnEdlkñúgenaHCMnan; in which an asexually reproducing generation is followed by a bnþBUCeday\tePTRtUv)anbnþedayCMnan;bnþBUCedayePT. sexually reproducing generation. altricial (adj) : Young animals that are born at an early stage of ekItmunkMNt; ³ EdlekItmkqab;eBk muneBlkMNt; nigTamTar development and are helpless. eGaymankarCYyEfTaMnigciBa©wmBIem)a. Alu sequence : An DNA sequence Alu ADN of approximately 300 bp long, tMnlMdab; ³ tMnlMdab; manRbEvgRbmaNCa 300KU)as interspersed by other sequences. It is found in the of primates eRCotcUledaytMnlMdab;déTeTot. tMnlMdab;enHRtUv)anrkeXIjkñúg and is cleaved by the restriction esNUmrbs;RBIma:t nigkat;edayGg;suImkMnt; Alu I . cMeBaHmnusSva)an enzyme Alu I. In humans, they are spread throughout the genome. tMerobBaseBjesNUm. mancMnYnBI 300>000 eTA 600>000 KWRbEhl There are 300,000 to 600,000 copies, which make up about 3 to 6 Ca3 eTA6 PaKryénesNUm. ¬emIl SINES ¦ percent of the genome. See SINES. alveolus (pl. alveoli) : A small cavity or pit, such as a microscopic kUnfg;sYt ³ kUnRbehag rWreNþA dUcCakUnfg;xül;tUc²kñúgsYt air sac of the lungs, terminal part of an alveolar gland, or bony socket EpñkbBa©b;énRkeBjkUnfg;sYt rWreNþAeFµj. of a tooth. amber codon : The codon UAG, UAG which does not code for an amino kUdugbBa©b; ³ kUdug EdlmincMlgRkmsMrab;GasuItGamIen bu:Enþ acid but for chain termination. see stop codon stop codon. sMrab;bBa©b;Rcvak;GasIutGamIen. emIl . Ames test : An assay developed by Ames Bruce Ames Bruce Ames to detect compounds etsþ ³ karviPaKeFVIeLIgedayelak edIm,IrkeGay that cause and cancer. The test measures the frequency of eXIjsmasFatuEdlbNþaleGaymanmuytasüúg nigmharIk. etsþenH back mutations in histidine- vas;BIeRbkg;muytasüúgRtlb;kñúg)ak;etrI Salmonella typhimurium dependent Salmonella typhimurium bacteria, so that the mutants do not EdlGaRs½yedayGuIsÞIDIn dUecñHmuytg;minRtUvkarkarbMeBj GuIsÞIDInbEnßm need histidine supplements in their food supply. kñúgGaharrbs;vaeT. amide : Nitrogen-containing compound derived from an acid GamId ³ smasFatumanGasUt)anmkBIGasIut nigGamIn EdlmanTMrg; and an amine with the general structure TUeTA ³ O O R C NH2 R C NH2

amine : Organic compound in which a nitrogen is the central GamIn ³ smasFatusrIragÁEdlkñúgenaHGasUtCaFatusMxan;énRkum- member of the functional group. Since nitrogen atoms have three muxgar. GatUmGasUtmansm<½n§bI Etmansm<½n§EtmYyb:ueNÑaHEdlP¢ab; bonds, only one of which connects eTAnwgGIuRdÚkabYExSem. vaGacCMnYsbEnßmRkúmGal;KIlelIGasUtenaH. to the parent hydrocarbon, it is possible to substitute additional alkyl groups on this nitrogen. amino acid acceptor site : A sequence of that tMbn;TTYlGasuItGamIen ³ lMdab;nuyekøGUTItEdlTTUlsÁal; nigcg recognizes and binds to a specific 3’ ARN amino acid at the 3’ end of a P¢ab;eTAnwgGasuItGamIenyfaRbePTenARtg;cug rbs;m:UelKul molecule of transfer RNA. dwknaM. amino acids : Class of biological compounds whose members GasIutGamIen ³ fñak;énsmasFatuCIv³ Edlman RkúmGamIn nigRkúm possess both an amino group and a carboxylic group. Amino kabuksIul. GasIutGamIenCaFatubgáénbiubTIt nigRbÚetGIun. PaKeRcInén acids are the building blocks of GasIutGamIensMxan;²kñúgFmµCati KWCaGasIutGamIenGal;hVa. emIlTMBr½ peptides and proteins. Most of the important natural amino acids are 317 . alpha-amino acids. See p. 317. aminoacyl tRNA : Covalently ARNt ARN linked combination of an amino GamINUGasuIl ³ bnSMénmU:elKul t nigGasuItGamIen Edl acid and a tRNA molecule. P¢ab;Kñaedaysm<½n§kUva:Lg;. aminoacyl-tRNA synthetase : A ARNt type of enzyme that catalyzes the GamINUGasIul saMgEttas ³ Gg;suImmYyRbePTEdleFVI binding of an amino acid to the amino acid acceptor site on a ktþalIkmµrvagcMNgGasuItGamIeneTAnwgkEnøgTTYlGasuItGamIenenAelI molecule of transfer RNA. m:UelKul ARNt . amitosis : Cell division by simple fission of the nucleus and GamItUs ³ cMENkekasikaedaykarEbgEckéNVy:U nigsIutU)øasy:ag cytoplasm without chromosome differentiation. samBaØedayKµanbMElgÉkeTsénRkUm:UsUmeT. ammonotelic : Excreting nitrogenous wastes primarily as beBa©jGasUt ³ karbeBa©jsMNl;GasUtCasMxan; dUcCaGamU:j:ak;. ammonia. amniocentesis : A procedure by which amniotic fluid is withdrawn viFIbUmykTwkePøaH ³ viFIbUmykTwkePøaHenAeBlmanépÞeBaHedIm,Irk during pregnancy to detect genetic defects. vibtþiesenTicénTark. amnion : A sac filled with fluid that encloses an embryo and fg;TwkePøaH ³ fg;manvtßúraveRsabB½T§CuMvijGMRb‘Íy:ug nigkarBarGMRb‘Íy:ug. protects it. amniotes : Those vertebrates whose embryos possess an amnion, stVmanTwkePøaH ³ stVq¥wgkgEdlGMRb‘Íy:ugmanTwkePøaHbIRsTab;KW chorion, and allantois (i.e., turtles, amnion, chorion allantois lepidosaurs, crocodilians, birds, nig ¬ ]TahrN_³ GeNþIk-RkeBI-bkSI and mammals). nigfnikstV ¦. amniotic fluid : The liquid contained inside the amniotic sac. TwkePøaH ³ vtßúravkñúgfg;TwkePøaH. amoebocyte : An unspecialised cell type having several different ekasikaGamIb ³ RbePTekasikaKµanbMElgÉkeTs b:uEnþmanmuxgar functions in sponges. eRcInepSg²KñaéneGb:ug. amphetamine : A group of drugs that act as stimulants on the central GMeptamIn ³fñaMmYyRkummannaTIePJaceTAelImCÄmNÐlRbB½n§RbsaT. nervous system.

amphicoelous : Vertebral centrum with both the anterior and posterior GMPIEsl ³ EdlmanépÞptxagmuxnigxageRkay cMeBaHq¥wgxñgEpñk surfaces concave. kNaþl. amphidiploid : See allotetraploid. GaMPIDIbøÚGuIt ³ emIl allotetraploid . amphipathic molecules : Molecules with both polar and m:UelKulGMPI)a:Tic ³ m:UelKulEdlmanTaMgtMbn;b:UlnigtMbn;Kµanb:Ul. non-polar regions. amphoteric molecule : Molecule that functions as a base in the m:UelKulGMpUET ³ m:UelKulEdledIrtYCa)askñúgvtþmanGasIut nigCa presence of an acid and as an acid in the presence of a base. GasIutkñúgvtþman)as. amylase : An enzyme that breaks down carbohydrates into smaller GamILas ³ Gg;suImEdlbMEbkkabUGIuRdateTACaÉktatUc²edayGIuRdÚlIs units by hydrolysis of α -1,4- elIsm<½n§KIøkUsIut α -1,4-. glycosidic bonds. amylopectin : A polymer made of up to 50,000 molecules of GamILÚbiucTIn ³ b:UlIEmrEdlekIteLIgBIm:UelKulKøúykUsGal;hVarhUt alpha-glucose with many branches. dl; 50000m:UelKulEdlmanédeRcIn. amyloplast : A type of plastid that stores starch. GamILÚ)aøs ³ )aøsÞItmYyRbePTEdlpÞúkGamIdug . amylose : An unbranched chain of up to several thousand molecules GamILÚs ³ Rcvak;Kµanéd énKøúykUsGal;hVarab;Ban;m:UelKul. of alpha-glucose. anabolism : Part of metabolism that uses energy to build larger, GsmaNkmµ/ GaNabUlIs ³ EpñkénemtabUlIsEdleRbIfamBledIm,I more complex molecules from simpler ones. Biosynthesis. begáItm:UelKulFMCag saMjaMúCagecjBIm:UelKulgayCag. CIvsMeyaK. anadromous : Migrating up a stream or river from a lake or pøas;lMenAeLIgBg ³ pøas;lMenABIbwgrWsmuRTeTAsÞwgrWTenøedIm,IBg ocean to spawn (of fishes). See catadromaous catadromous. ¬RtI ¦. emIl . anaerobic : Not requiring oxygen. Kµanxül; rWminRtUvkarxül; ³ EdlminRtUvkarGuksIuEsn. anaerobic respiration : A ATP biochemical pathway that does not degðImKµanxül; ³ dMeNIrKImICIv³minRtUvkarGuksIuEsn edIm,IbegáIt require oxygen for the production nigmineRbIGuksIuEsnsMrab;TTYlykGIuy:ugGIuRdUEsneT. of ATP and does not use 0 2 as its hydrogen ion acceptor. anal fin : A single fin located ventrally near the tail of a bony RBuyKUT ³ RBuyeTalsßitenAxageBaHCitknÞúyénRtIq¥wg. fish. anal pore : The structure in paramecia through which rn§TVarFM ³ cMeBaH):ar:aemsIu CaTMrg;rn§EdlsarFatuminRtUv)anrMlay undigested material is expelled from the cell. RtUv)anbeB©ajeTAeRkA. analogue : A chemical compound structurally similar to another, but GaNaLÚk ³ smasFatuKImI manTMrg;RsedogKñaeTAnwgsmasFatuKImI differing by a single functional group (e.g., 5-bromodeoxyuridine mYyeTot bu:EnþxusKñaedayRkummuxgareTal¬]TahrN_ 5-RbUmU:edGuk- is an analogue of thymidine). suIGu‘yrIDIn KWCaGaNaLÚkénTImIDIn ¦. anaphase : The third stage of during which GaNapas ³ vKÁTI3énmItUsEdlkñúgkMLúgeBlenaH sg;®tUEmrEckxøÜn split and sister become separate chromosomes that begin nigRkUm:aTItbgb¥ÚnkøayCaRkUm:UsUmdac;BIKñaEdlcab;epþImrMkileq

anaphase I : The first anaphase of I . Homologous GaNapas ³ GaNapasTImYyénemy:Us. ®kUm:UsUmGUm:ULÚkeFVIdMeNIr chromosomes move to opposite poles of the meiotic spindle eTAkan;b:UlpÞúyKñaénRty:UgGaRkUm:aTicénemy:Us Edl)aneFVIeGaycMnYn apparatus, resulting in a halving of ®kUm:UsUmBak;kNþaleFIVdMeNIreTAkan;éNVy:UkUnerog²xøÜn. the number of chromosomes going to each daughter nucleus. anaphase II : The second II II anaphase of meiosis; the GaNapas ³ GaNapasTIBIrénemy:Us . enAkñúgGaNapas centromeres divide, thereby allowing the separation of sister enH sg;®tUEmrEckxøÜn ehIy)aneFVIeGayman karEbgEck®kUm:aTItbgb¥Ún chromatids into independent køayeTACa®kUm:UsUmÉkraCü. chromosomes. androecium (pl. androecia ) :

Collectively, all of the stamens of a kBa©úMeksreQµal ³ eksreQµalTaMgGs;rbs;páaeTalmYy. single flower. androgens : Male sex hormones produced by the testes that cause Gg;RdÚEsn ³ Grm:UnePTeQµalplitedayBgsVas nigbNþaleGay the differentiation of typical internal and external genital male manbMElgÉkeTslkçN³ePTeQµalTaMgxagkñúg nigxageRkA . anatomy. anemia, or anaemia : A disease condition in which the oxygen- kgVHQamRkhm ³ sßanPaBCMgWEdlsmtßPaBdwknaMGuksIuEsnrbs; carrying capacity of the blood is reduced, due to low number of red QamfycuH edaysarkarfycuHéncMnYneKalikaQamRkhm b¤fycuHén blood cells, or in their volume or cMnYneGm:UkøÚb‘Ín. haemoglobin content. aneuploidy : A condition in which the chromosome number is not an GaNWbøÚ:GuIDI ³ sßanPaBEdlkñúgenaHcMnYnRkUmU:sUmminEmnCaBhuKuN exact multiple of the haploid set. RtwmRtUvéncMnYnGabøÚGuIteT. angiosperm : A flowering plant. The most advanced and recently Gg;süÚEs

annulation : External division of a worm-shaped body into a series of karx½NÐCakg; ³ karEbgEckdgxøÜnEdlmanragdUcCadgáÚv Caes‘rIkg rings. xageRkA. anomeric carbon : Carbon atom in the cyclic form of sugars that kabUnGaNUEm ³ GatUmkabUnkñúgTMrg;CasiucénsárEdlCakabUnkabUnIl had been the carbonyl carbon of the open-chain form. rbs;TMrg;ExSebIk. anomers : Pair of isomers that forms when a monosaccharide GaNUEm ³ KUénGIusUEmrEdlekItmaneBlm:UNUsak;karItmanTMrg;Ca forms a ring. The oxygen attached to the anomeric carbon can have siuc. GuksIuEsnEdlP¢ab;nwgkabUnGaNUEmrGacman dMeNATisCaebta either a beta (β) (“up”) or an alpha (β) : xagelI : rWCaGal;hVa (α) : xageRkam : ¦. (α) (“down”) orientation. anorexia nervosa : A nutritional deficiency disease characterized by karP½yxøacFat; ³ CMgWxVHsarFatuciBa©wmsMKal;edaykarcuHTMgn;ry³ severe, prolonged weight loss for fear of becoming obese. This eBlyUreRBaHxøacFat;. vibtþiénkarhUbenHRtUv)aneKKitfabNþal eating disorder is thought to stem mkBIktþasgþmvb,Fm’. from socio-cultural factors. antagonistic pair : Two muscles that oppose each other so that one KUbdibkç ³ sac;duM2EdleFIVkarpÞúyKña mYykRnþak; mYybn§Úr. contracts as the other relaxes. See biceps and triceps biceps and triceps. emIl . antenna : Sensory appendage in mandibulate arthropods. Gg;Etn ³ ExñgviBaØaNkñúgExñgmat;rbs;GakRtUb:Ut. anterior : At the front part of an . xagmux ³ enAEpñkxagmuxb¤Epñkxagk,alstV. anther : The part of a stamen that holds the pollen. e)øaklMGg ³ Epñkrbs;eksreQµalEdlmanpÞúklMGg. antheridiophore : In some liverworts liverworts, the stalk that bears Gg;etrIdüÚpr ³³³TgEdlpÞúkGg;etrIDIénrukçCati³ mYycMnYn. antheridia. antheridium : A sperm producing structure found in some plants. Gg;etrIdüÚm ³ TMrg;plitEs

anticodon : Three nucleotide bases ARN found on each transfer RNA that Gg;TIkUdug ³ )asnuyekøGUTItbIenAelI dwknaMnimYy²EdlcMlgRkm code for a specific amino acid and ARN complement the codon on sMrab;GasuItGamIenyfaRbePT nigbMeBjCamYykUdugrbs; naMsar. messenger RNA. antidiuretic hormone (ADH) : ADH A hormone produced by the Grm:Un ³ Grm:UnplitedayGIub:UtaLamusEdltMrUvkarRsUbTwkkñúg hypothalamus that regulates the vasopressin reabsorption of water in the tMrgenam . vak¾RtUv)aneKehAfa pgEdr. kidney; also called vasopressin. antigen : Large foreign molecules within the body (often a cell Gg;TIEsn ³ m:UelKulcMELkFM²EdlfitenAkñúgsarBagÁkay ¬PaKeRcIn surface protein or carbohydrate), that induces an immune response CaRbUetGuInépÞekasikab¤CakabUnGuIRdat ¦EdlbNþaleGaymancMelIytb which includes the formation of PaBsuaMmYyEdlrYmmankarbegáItGg;TIk. antibodies. antiparallel : Refers to ADN double-stranded DNA, in which pÞúyKña rWminRsb ³ sMedAeTAelIm:UelKul Rcv:ak;eTV EdlTisedA the direction of each strand is opposite to its complementary rbs;Rcvak;nImYy² KWpÞúyKñaeTAnwgRcvak;bMeBjrbs;va. strand. antipodal cell : Cells that form the embryo sac, opposite the ekasikaGg;TIb:Ut ³ ekasikaEdlekIteLIgenAkñúgfg;GMRb‘Íy:ugQmnwg micropylar end. mIRkUBIl. antisense strand : In DNA, the antisense strand of a gene is the Rcvak;bdin½y ³ Rcvak;bdin½yrbs;EsnmYy KWCaRcvak;minpÞúklMdab; one that does not contain a coding ARN sequence for a molecule of RNA; RkmsMrab;sMeyaKm:UelKul ehIyRcvak;bdin½yenHmin®tUv)anbkERb the antisense strand is not RkmeT. transcribed. anus : Posterior opening of the alimentary canal through which TVarFM ³ rn§xagcugbMBg;rMlayGahar EdlsarFatuminRtUv)anrMlayRtUv undigested material is expelled from the body. )anbeBa©jBIsarBagÁkay. aorta : A large artery leading from 322 the heart. See p. 322. GaGk ³ srésGaETFMecjBIebHdUg. emIlTMBr½ . aortic semilunar valve : Valve in the heart at the base of the aorta. RbwsGaGk ³ RbwsKl;GaGkenAkñúgebHdUg. aphotic : Without light e.g. in deep-sea habitats or caves. KaµnBnøW ³ ]- kEnøgrs;enA)atsmuRTeRCA b¤kñúgrUg. apical dominance : The reduction in growth of lateral buds caused by lubkMBUl ³ karfycuHnUvkarlUtlas;rbs;BnøkEmk bNþalmkBI the presence of a terminal bud. vtþmanénBnøkRtYy. apical meristem : Unspecialised cells that divide to produce new emCalikakMBUl ³ ekasikaminbMElgÉkeTsEdleFIVcMENk edIm,IbegáIt cells at the tips of roots or shoots. ekasikafµI²enAk,alrws b¤cugRtYy. apocrine gland : Type of gland in which the apical part of the cell RkeBjGab:URKIn ³ RbePTRkeBjEdlEpñkxagcugénekasikabeBa©j from which the secretion is holocrine gland released breaks down in the RtUv)anpþac;ecjkñgdMeNIrbeBa©j. emIl . process of secretion. See holocrine gland . apoenzyme : The protein part of cofactor an enzyme that requires a cofactor GabU:Gg;suIm ³ EpñkRbUetGuInrbs;Gg;suImmYy EdlRtUvkarRkum or prosthetic group to be prostheric functional. b¤Rkum edIm,IeFVIeGaymandMeNIrkar.

apomixis: Asexual reproduction of seeds. Gab:UmicsIus ³ karbnþBUCeday\tePTénRKab;. apomorphic : A character that is changed from its preexisting lkçN³ERbRbÜl ³ lkçN³Edlpøas;bþÚrxusBIlkçN³edImrbs;va. condition. See autapomorphy . emIl autapomorphy . apoplastic movement : The movement of water and solutes in clnaGab:U)aøsÞic ³ clnaTwk nigsarFaturlaykñúglMhcenøaHCalika the free of the tissue; the free space includes cell walls and EdlcenøaHenHrYmman PñaseRKagnigcenøaHGnþrekasika. intercellular spaces. aposematic : Device (color, sound, behavior) used to advertise the Gab:Uesm:aTic ³ RBmanedaymeFüa)ay ¬BN’ semøg Gakb,kiriya ¦ noxious qualities of an animal. edIm,IbgðajPaBBisBulrbs;xøÜnénstVNamYy. apothecium : An open ascocarp; it is usually cup or saucer-shaped. Gab:UetsüÚm ³ GasáÚkabcMhEdlCaTUeTAmanragdUcEBg rWfas. appendage : Any structure that grows out from the main part of the Exñg ³ TMrg;EdlduHecjBIEpñksMxan;énxøÜn. body. appendicular skeleton : The pelvic and pectoral girdles and eRKagq¥wgbrisidæ ³ q¥wgRtKak q¥wgsµa nigq¥wgGvyv³stVVq¥wgkg. limb bones in vertebrates. appendix : A small projection from the large intestine that helps ExñgeBaHevon ³ ExñgtUcmYyduHecjBIeBaHevonFM EdlCYyrMlayEslu- digest cellulose in some animals but has no significant function in yLÚscMeBaHfnikstVmYycMnYn b:uEnþKµanmuxgarsMxan;cMeBaHmnusSeT. humans. See p.322. emIlTMBr½ 322 . aquatic respiration : In organisms that live in water, exchange of degðImkñúgTwk ³ cMeBaHPavrs;Edlrs;enAkñúgTwk KWCakarbþÚrGuksuIEsn nig oxygen and CO 2 from water. Some have special structures with large ]sµ½nkabUnicBITwk. cMeBaHPavrs;mYycMnYnmanTMrg;Biess épÞFM ]TahrN_ surface areas e.g. gills in fish. ³RskIRtI. aqueous humour : Fluid between the cornea and lens in the TwkkBa©k;EPñk rWGu‘ym½rTwk ³ KWCavtßúravEdlsßitenAcenøaHrvagken nig vertebrate eye. EkvEPñkénstVq¥wgkg. aquifer : A layer of rock underground that can hold water. GaKIEP ³ RsTab;fµeRkamdIEdlGacpÞúkTwk)an. arcade : Curve or arch in a structure, such as the tooth row of Gakat ³ TMrg;CaExSbnÞat;ekag rW ragFñÚdUcCYreFµjmnusS. humans. archaebacteria : Primitive with distinctive Gaek)ak;etrI ³ RbUkarIy:UtCan;edImEdlmanTMrg; niglkçN³KImIxus² chemical and structural features. 312 see p. 312. BIKña. emIlTMBr½ . Archaeopteryx : An extinct fossilised animal that represents a GaekGubetric ³ stVpUsIulnigvinassabsUnü EdltMNageGay stage in the evolution of reptiles to birds. dMNak;kalvivtþBIlµÚneTAbkSI. archaic : Form typical of an earlier evolutionary time. When a capital Can;cas; ³ TMrg;éndMeNIrvivtþn_kalBIsm½yedIm. eBlsresrGkSrFM KW letter is used, it refers to the 2.5 Archaeozoic period, more than 2.5 CayuKsm½yGaekeGogEdlmanGayuCag Ban;lanqñaM. billion years ago. See p. 320. emIlTMBr½ 320 . archegoniophore : In some Liverwort liverworts, the stalk that bears GaekkUNüÚpr ³ TgEdlpÞúknUvGaekkUnénrukçCati mYycMnYn. archegonia.

archegonium : An egg producing reproductive structure in mosses. GaekkUn ³ TMrg;bnþBUCrbs;EsøEdlbegáItkaEm:tjI. archenteron : A cavity that eventually becomes the digestive Gakg;etru:g ³ RbehagEdlnwgkøayCabMBg;rMlayGaharstVeBjv½y b¤ tract of the adult or larva; formed 2 during the development of a kUnjas;. vakekIteLIgenAkñúgkMLúgeBlénkarlUtlas;RsTab;TI én deuterostome embryo. GMRb‘Íy:ug. archipterygium : Fin skeleton, as in a lungfish, consisting of GaKIbetrIsüÚm ³ eRKagq¥wgRBuy ¬cMeBaHRtImansYt ¦ EdlmankaMtMerob symmetrically arranged rays that extend from a central skeletal axis. suIemRTIKña latsn§wgecjBIG½kSeRKagq¥wg. aril : A fleshy structure that may partially envelop a seed. GarIl ³ TMrg;sac; EdlGacmanEpñkxøHeRsabRKab;. aromatic : Class of ring compounds that have alternating Gar;:Um:aTic ³ fñak;énsmasFatuCasiucEdlmankarqøas;sm<½n§BIrCan;nigkar double bonds and subsequent pi electron delocalization. An BRgayeGLicRtúg πbnÞab;mk ehIysmasFatuGar:Um:aTiceKarBtamviFan aromatic compound obeys the 4n + 2 4n + 2 rule. . Arrhenius’s model for an acid : Arrhenius Svante- Arrhenius Idea proposed by Svante Arrhenius KMrU sMrab;GasIut ³ )anelIkeLIgfa that acids are molecules that ionize to produce hydrogen ions when GasIutCam:UelKulEdlbMEbkCaGIuy:ug edIm,IbegáItCaGIuy:ugGIuRdÚEsnrWRbÚtug placed in water. enAeBldak;vaeTAkñúgTwk. arteriole : A small artery. kUnGakET ³ GakETtUc. arterioscelosis : A disease in which the walls of the blood CMgWRkinsrésQam ³ CMgWEdlPñassrésQameLIgRkas;ehIyrwg. vessels thicken and harden. artery : A blood vessel with thick elastic muscular walls, that carries GakET ³ srésQamEdlmanépÞsac;dMuRkas;nigyWt EdldwknaMQam blood away from the heart. See p. 323 323. ecjBIebHdUg. emIlTMBr½ . artificial selection : Selection by humans of specific traits in CMerIsnimit ³ CMerIsedaymnusS nUvlkçN³yfaRbePTénPavrs;EdleK organisms being bred to produce desired characteristics. kMBugbgáat; edIm,IbegáItlkçN³EdleKcg;)an. ascocarp : A reproductive asci structure of ascomycetes, in which GasáÚkab ³ TMrg;bnþBUCrbs;GasáÚmIEst EdlGas ¬ ¦®tUv)anbegáIt asci are formed. eLIg. ascogenous hyphae : Hyphae with paired male and female nuclei; GIuhVbegáItGas ³ GIuhVEdlmanKUéNVy:UjI nigeQµal EdlbegáIt)anCa ascogenous hyphae eventually asci) produce asci. Gas ¬ . ascogonium (plural: ascogonia) :

The female sexual structure of GasáÚkUn ³ TMrg;bnþBUCjIrbs;GasáÚmIEst. ascomycetes. ascomycetes : A large group of true fungi with hyphae that have GasáÚmIEst ³ CaRkumd¾FMénpSitBitEdlGuIhVmansnÞHx½NÐ ¬emIl septa (see septum ); they produce septum conidiospores asexually and ¦. vabegáItkUnIdüÚs,:\tePT nigGasáÚs,:manePTenAkúñgGas. ascospores sexually within asci. ascospore : A spore produced within an ascus. GasáÚs,: ³ s,:Edl®tUv)anplitkñúgGas. ascus ( plural asci) : In fungi, the 4 8 sac enclosing the four or eight Gas ³ cMeBaHpSit vaCafg;bitEdlmanGasáÚs,: b¤ . ascospores.

-ase : Suffix used to indicate that the substance is an enzyme. -Gas ³ bc©½yEdl)aneRbIedIm,IbBa¢ak;fasarFatuenaHCaGg;sIum. asexual reproduction : A method of producing offspring without the karbnþBUCeday\tePT ³ viFIbnþBUCedayKµankarrlaycUlKñaén joining of two gametes; binary fision, reproduction without fertilization. kaEm:tBIreT. karbnþBUCedayKµankarbgákMeNIt. emIl See binary fision, budding, budding, fragmentation, sporulation, vegetative propagation . fragmentation, sporulation, vegetative propagation. assay : The qualitative determination of the components of kareFIVviPaK b¤kareFIVetsþ ³ karkMNt;KuNPaBénFatubgárbs;fñaM . a drug. assimilation : The physiological process that takes place in a living smankmµ ³ dMenIrsrIr³enAkñúgPavrs;EdlbMElgcMNIGahareGayeTACa cell as it converts nutrients in food into specific molecules required by m:UelKulyfaRbePTEdlPavrs;enaHRtUvkar. the organism. associative learning : See classical conditioning classical conditioning. karsikSal½kçx½NÐ ³ emIl . assortative mating : Mating between males and females of a karbnþBUCkñúgRkum ³ karbgáat;rvagePTeQµalnigePTjIénRbePTmYy species in which the choice of partner is affected by the genotype, EdlkñúgenaHCMerIsédKU TTYl\T§iBledayesNUTIb KWfakarbgáat;mintam i.e. mating is non-random. karécdnüeT. kareRCIserIsKYbgáat;EdlesNUTIbdUcKña KWviC©man Selection of mates with the same genotype is positive; selection of ehIykareRCIserIsKUbgáat;EdlmanesNUTIbpÞúyKña KWGviC©man. mates with opposite genotypes is negative. astral rays : Fibrils that form around the centriole during mitosis. vg;kaMsrés ³ srésekIteLIgCuMvijsg;RTIy:UlenAeBlmItUs. asymmetrical : Lacking any regular shape. minsIuemRTI ³ ragminesµIKña b¤minsuIKña. atmosphere (atm) : Normal 1atm 760mm Hg atmospheric pressure, where 1.00 Gat;mU:EsV‘ ³ sm

atomic number : Number of protons (positive charges) in the elxGatUm rWelxlMdab; ³ cMnYnRbÚtug :bnÞúkviC¢man : enAkñúgéNVy:U nucleus of an atom. The atomic number is also the number used to rbs;GatUm. elxGatUmCaelxEdleRbIpgEdrsMrab;bBa¢ak;TItaMgrbs;Fatu position an element in the periodic kñúgtaragxYb nigerobrab;cMnYneGLicRtúgenACMuvijéNVy:Urbs;GatUmNWt. table and to describe the number of electrons surrounding the nucleus of a neutral atom. ATP (see adenosine ATP triphosphate) : A compound that ³ smasFatuEdlsþúkfamBlcaM)ac;sMrab;RKb;skmµPaBrbs; stores the energy needed for all ekasika. cellular activities. ATP phosphohydrolase (ATPase) ATP : A type of transport protein that pUsVrGIuRdÚLas ³ RbUetGuIndwknaMmYyRbePTEdleRbIR)as;famBl uses energy from the hydrolysis of ATP ATP to actively transport ions or BIkareFVIGuIRdUlIs edIm,IdwknaMy:agskmµnUvGuIy:ug b¤sarFaturlay other solutes against their epSg²eTot Tl;nwgkMritkMhab;rbs;va. concentration gradient. ATP synthase : A type of ATP membrane-bound enzyme in saMgtas ³ RbePTGg;suImCab;PñasenAkúñgmItUkugRTI EdlbEnßm mitochondria that adds phosphate ADP ATP to ADP to form ATP by using m:UelKulpUsVateTAelI edIm,I)anCa edayeRbIfamBlbnSay energy from the diffusion of BIRbUtugtamry³Gg;suIm. protons through the enzyme. atrioventricular valves : Valves located between the atria and RbwsftelI-eRkam ³ RbwscenøaHftelInigfteRkamebHdUg EdlTb; ventricles of the heart that prevent the blood from flowing backward QammineGayhUrRtlb;BIfteRkamebHdUgeTAftelIebHdUgvij. from the ventricles into the atria. atrium : The heart chamber that receives blood from the veins in ftelIebHdUg ³ ftebHdUgEdlTTYlQamBIEv:n cMeBaHstVq¥wgkg. vertebrates; the auricle. attached-X chromosome : Two X X 2 joined X chromosomes that share a RkUmU:sUm Cab;Kña ³ RkUmU:sUm Cab;Kña Edlmansg;RtUEmrYmKñaEtmYy. single centromere. attachment site : A specific point on the surface of the enzyme where kEnøgPa¢b; ³ kEnøgEdlGg;sIumP¢ab;eTAnwgs‘ubRsþa. cMnucyfaRbePT it can physically attach itself to the substrate; also called binding site. enAelIépÞGg;sIum EdlP¢ab;Gg;sIumeTAnwgs‘ubRsþa GacehAfakEnøgcg P¢ab;pgEdr. attenuator : A nucleotide sequence between the promoter GaefnüÚeGF½r ³ lMdab;nuyekøGUTItrvagcMnuccab;epþImnigEsnTMrg; én and the structural gene of some ARN operons that can act to regulate the GUeb:ru:gxøHEdlGaceFVIskmµPaBtMrUvkarqøgkat;rbs;Gg;suIm bU:lIEmra:s transit of RNA polymerase and dUecñHvaeFVIkarRtYtBinitüelIkarcMlgRkménEsnTMrg;. thus control transcription of the structural gene. auditory canal : The outer ear canal leading to the eardrum. rn§RtecokeRkA ³ bMBg;rn§RtecokBIeRkAdl;RkdasRtecok. aural : Of the external or internal ear or sense of hearing. énRtecok ³ énRtecokeRkA rWRtecokkñúg rWesatviBaØaN. auricle : An ear-like growth at the top of the leaf sheath in grasses. Rtecoksøwk ³ TMrg;dUcsøwkRtecokEdlduHenAcugRsTbsøwkénrukçCati RkamIen. autapomorphy : An attribute unique to one group of organisms. GUtab:UmPI ³ lkçN³EtmYyKt;rbs;RkummYyénPavrs;. autochthonous : With an origin in the region where found. tMbn;edIm ³ EdlmanedImkMenItenAkñúgtMbn;EdlRbTHeXIj.

autogamy : A process of self-fertilization resulting in GUtUkamI ³ dMeNIrsV½ybgákMenItEdlbegáIt)anCaGUmU:suIkUt. homozygosis. autoimmune disease : The production of antibodies that CMgWsV½yPaBsaMu ³ karplitGg;TIk EdlCalT§plénkareqøIytbrbs; results from an immune response to a person’s own molecules, cells, PaBsaMueTAnwgmU:elKul ekasika b¤CalikapÞal;rbs;mnusSmñak;. cMelIy or tissues. This response results tbenHbNþalmkBIGsmtßPaBénRbBn§½PaBsuaM kñúgkarEbgEckekasika from the inability of the immune system to distinguish its own cells rbs;vapÞal; BIekasikaepSgeTot. CMgWxøHdUcCa QWsnøak;éd-eCIg CMgW;rwg from other cells. Diseases such as arthritis, scleroderma, systemic Es,k / CMgWesIEs,kbNþalmkBIkarsÞHQam b¤rlak nigRbEhlCa lupus erythematosus, and perhaps diabetes are considered to be eraKTwkenamEp¥mpgEdr RtUv)aneKKitfaCaRbePTCMgWsV½yPaBsaMu. autoimmune diseases. autonomic nervous system : Motor neurons that connect the RbB½n§RbsaTsV½yRbvtþ ³ NWrU:nclkrEdlP¢ab;RbB½n§mCÄmNÐl central nervous system to smooth muscles, cardiac muscles, and RbsaTeTAsac;duMrlIg sac;duMebHdUg nigRkeBj. vaRtYtBinitüskmµPaB glands. It controls the involuntary GqnÞ³rbs;sarBagÁkay. emIlenA Sympathetic nervous system and activities of the body. See Sympathetic nervous system and Parasympathetic nervous system . Parasympathetic nervous system. autopolyploid : A polyploid with n multiple sets of chromosomes that sV½yb:UlIbøÚGuIt ³ b:UlIbøÚGuItEdlRkumRkUm:UsUmekIteLIgtamBhuKuNén comes from more than one species. EdlekItmkBIRbePTeRcInCagmYy. autoradiography : Production of a photographic image by radioactive sV½yviTüúft ³ karplitrUbftedaykarbMEbkvITüúskmµ. viFIenHRtUv)an decay. Used to find the position of radioactively labelled compounds eKeRbIedIm,IrkTItaMgsmasFatuEdlmansBaØaviTüúskmµenAkñúgekasika within cells and tissues. nigCalika. autosome : Any chromosome other than the sex chromosomes. RkÚm:UsUmFmµta ³ RkUm:UsUmTaMgLayNaEdlminEmnCaRkUm:UsUmePT. autotroph (adj. autotrophic) : An organism that can produce its food sV½yCIB ³ Pavrs;EdlGacsMeyaKGaharrbs;vaBIsarFatugay dUcCa from simple substances, such as carbon dioxide. ]sµ½nkabUnic. ]>rukçCati. auxin : A plant hormone (growth regulator) that influences cellular GuksIun ³Grm:UnrukçCatimYyRbePT ¬niy½tkrkarlUtlas; ¦ Edlman elongation: also referred to as indole-3-acetic indole-3-acetic acid, or 1AA. \T§iBleTAelIkarlUtEvgrbs;ekasika. vak¾sMedAeTAelI acid b¤ 1AA pgEdr. auxotroph : A mutant microorganism or cell line which GUsURtUb ³ mIRkUsarBagÁkay b¤ekasikamuytg; EdlRtUvkarsarFatu requires a substance for growth that can be synthesized by edIm,IlUtlas; EdlGacRtUv)ansMeyaKedayBUCéRB. wild-type strains. Avogadro’s number : Number of atoms or molecules in 1 mole of a cMnYnGav:UkaRdÚ ³ cMnYnGatUm rwmU:elKulkñúgmYym:Ulrbs;sarFatumYy 23 substance, which is 6.023 x 10 . EdlesµInwg 6,023 x10 23 . awn : In grasses, a bristle like structure that extends from the knÞúysMbk ³ cMeBaHrukçCatiRkamIen CaTMrg;dUceramEdlduHlUtecjBI central veins of the lemmas. RTnugénsMbkxñgRKab;. axial filament : A series of fibres that are part of a cilium or PILam:g;G½kS ³ esrIsrésqµar²EdlCaEpñkrbs;eramj½r b¤pøaEsl. flagellum.

axial skeleton : The skull, vertebral column and rib cage in eRKagq¥wgG½kS ³ cMeBaHstVq¥wgkg q¥wgllak,al q¥wgxñg nigq¥wgCMnIr. vertebrates. axil : The upper angle between the stem and a leaf. mMusøwk ³ RCugEkgxagelI rvagedImnigTgsøwk. axillary bud : Buds that occur in the axil of a leaf. BnøkEmk ³ RtYyBnøkEdlduHeLIgenARtg;mMusøwwk. axillary placentation : The attachment of ovules along the CMnab;tamG½kS ³ karCab;énGUvulenACMuvijG½kSénGUEv EdlmanftpÞúk central axis of an ovary that has lily more than one ovule-bearing GUvuleRcIn. ]TahrN¾ ³ páalIlI ¬ ¦. chamber; lily is an example plant that has axillary placentation. axolotl : A type of laval salamander capable of reproducing. Gak;sULút ³ RbePTkUnjas;rbs;saLam:g;EdlGacbnþBUC)an. axon : A long thin branch of a neuron that carries impulses away Gak;sUn ³ ExñgravEvgrbs;NWr:UnEdldwknaMcrnþRbsaTecjBItY from the cell body. ekasika. B B horizon (subsoil) : The layer of soil immediately beneath the RsTab;dIbnÞab; ³ RsTab;dICab;pÞal;BIeRkamRsTab;dIelI EdlCaTUeTA topsoil, usually about 25 to 50cm. thick. mankMras;RbEhl 25 eTA 50 s>m. bacilli : Rod-shaped bacteria. )asIu ³ )ak;etrIragdMbg. back-cross : A cross involving an ³ KWCakarbgáat;rvag CMnan; F1 eGetrU:suIkUt nigemb¤)a ¬b¤ F1, heterozygote and one of the P, bgáat;Rtlb; parents (or an organism with a genotype identical to one of the Pavrs;mYymanesNUTIbdUcTaMgRsugeTAnwgem rW)aenaH ¦. parents). background radiation : Radiation received from naturally radioactive kaMesµImCÄdæan ³ kaMrsµITTYl)anBIFatuviTüúskmµFmµCatikñúgbriyakas elements in the atmosphere and the 65% earth’s surface and from cosmic nigelIépÞEpndI ehIynigBIkaMrsIµGvkas. RbEhl énkaMrsµIRbcaMqñaM radiation. About 65 percent of our )anmkBIkaMrsµImCÄdæan. annual radiation dose comes from background radiation. bacterial lawn : A bacterial culture covering the culture RsTab;)ak;etrI ³)ak;etrIbNþúH EdllUtlas;BIelImCÄdæanbNþúH. medium uniformly. bacterio-chlorophyll : One type of chlorophyll that is the primary kør:UPIl)ak;etrI ³ kør:UPIlmYyRbePT EdlCaCatiBN’sMrab;cab;BnøW light-trapping pigment in green and purple photosynthetic bacteria. d¾sMxan;enAkúñg)ak;etrIrsµIsMeyaKBN’sVay nigébtg. bacteriophage : A virus that infects bacteria. )ak;etrIy:Upas ³ vIrusEdlbgáCMgWdl;)ak;etrI. bacteriostatic : A compound that inhibits the growth of bacteria, but Rbti)ak;etrI ³ smasFatuEdlraraMgkarlUtlas;rbs;)ak;etrI bu:Enþmin does not kill them. sMlab;vaeT. bacterium (pl. bacteria) : A very (1 µm – 10 µm) small (1 µm – 10 µm), unicellular )ak;etrI ³ RbÚkarIy:UtbrCIBÉkekasikatUc éRkElg. heterotrophic . balanced equation: A chemical equation in which the number of smIkarmanlMnwg ³ smIkarKImIEdlcMnYnGatUmnimYy²kñúgRbtikrnigkñúg each kind of atom in the reactants and products is the same. plitplesµIKña.

balanced lethals : Recessive, lethal genes, that are not alleles, Esnbgásøab;manlMnwg ³ EsnGn;bgáeGaysøab;EdlminEmnCaGaELl which are carried on different homologous chromosomes. When RtUv)anpÞúkenAelIRkUm:UsUmGUm:ULÚkxusKña. enAeBlPavrs;manpÞúkEsn organisms carrying balanced lethal bgásøab;RtUv)aneKbgáat;rvagKña manEtPavrs;EdlmanesNUmdUcem)a genes are interbred, only organisms with genotypes identical to the TaMgRsugeT EdlGacenArs;)an. parents (heterozygotes) survive. balanced polymorphism : Genetic polymorphism maintained in a BhusNæanmanlMnwg ³ BhusNæanesenTicEdlmanenAkñúgb:UBuyLa- population by natural selection. süúgedayCMerIsFmµCati. ball and socket joint : A type of joint allowing movement in many snøak;BhuTis ³ RbePTénsnøak;EdlGacmanclnaeRcInTis. different directions. bar : A unit of pressure; one bar is the atmospheric pressure of air at )ar ³ ÉktasMBaF. mYy :)ar : KWCasMBaFxül;briyakasenAkMrit sea level and room temperature. TwksmuRT eFobnigsItuNðPaBkñúgbnÞb;. barb : A branch from the central shaft of a feather. RBuysøab ³ eramEdlduHecjBIG½kSsøab. barbiturate : Any of a group of depressant drugs used to cause fñaMsrésRbsaT ³ RkumfñaMrMgab;GarmµN_EdlbNþaleGaygguyedk sleep or relaxation. b¤GarmµN_FUrRsal. barbules : Tiny hooks that connect the barbs of a feather. kUnRBuysøab ³ eramTMBk;tUc²EdlP¢ab;KñaCaRBuysøab. bark : All the tissue outside the vascular cambium in the woody sMbkeQI ³ CalikaxageRkATaMgGs;énkMbüÚmsrésnaMedImrukçCati. stem. Barr body : Densely staining Barr nuclear mass seen in the somatic GgÁ ³ karbnSúIBN’ma:séNVyU:eGayditxøaMg emIleXIjkñúgéNVyU: nuclei of mammalian females. Discovered by Murray Barr, this ekasikalUtlas; énfnikstVjI . GgÁenHRtUv)anrkeXIjedayelak body is thought to represent an Murray Barr nigRtUv)aneKKitfa vatageGayRkUmU:sUm X GskmµPaB . inactivated X chromosome. basal disk : A specialised area outside of the sessile organism eCIgTMr ³ tMbn;ÉkeTsxageRkAénPavrs;enAnwgkEnøgEdlÉktþP¢ab;eTA where a polyp attaches to the surface. nwgépÞénTMr. basal metabolic rate : The amount of energy required to GRtaemtabUlIs)at ³ brimaNfamBlEdlRtUvkaredIm,IrkSaskmµ maintain normal body activity while at rest. PaBFmµtaénsarBagÁkayenAeBlsMrak. base : 1. Any substance that combines with hydrogen ions to )as ³ 1- sarFatuEdlpSMCamYyGIuy:ugGIuRdUEsnbegáIt)anGMbil nigTWk. form a salt and water. Hydrogen ion acceptor. 2. one of the GñkTTYlykGIuy:ugGIuRdÚEsn rWRbÚtug. 2- FatubgámYykñúgcMeNamFatubgá components of nucleotides TaMgLayrbs;nuyekñøGUTIt. base analogue : Any chemical that has a similar structure to one of the )asGaNaLÚk ³FatuKImIEdlmanTMrg;RsedogKñaeTAnwgTMrg;)asmYykñúg bases in DNA or RNA, and so can ADN ARN act as a mutagen. See analogue. cMeNam)asTaMgLayrbs; b¤ ehIyGacmanGMeBICamuy- taEsn. sUmemIl analogue . base : A in which a nucleotide base is lost kar)at;bg;)as ³ muytasüúgEdlmankar)at;bg;)asnuyekøGUTItBI from the DNA sequence. lMdab; ADN .

base insertion : A mutation in which an extra nucleotide base is karbEnßm)as ³ muytasüúgEdlmankarbEnßm)asnuyekøGUTIteTAkñúg added to the DNA sequence. Ggát ;ADN . base pair (bp) : A pair of bp ADN: A T complementary nucleotides. In KU)as ¬ ¦ ³ KUmYyénnuyekøGUTItbMeBjKña. kñúg bMeBj DNA, A-T and G-C. In RNA, A-U G C ARN A U G C and G-C. See p. 319 nig bMeBj cMENkkñúg vij bMeBj nig bMeBj . emIlTMBr½ 319 . base substitution : A single base ADN change in a DNA molecule that karCMnYs)as ³ karpøas;bþÚr)asmYykñúgmU:elKul EdlbNþal produces a mutation. There are two types of substitutions: transitions, eGaymanmuytasüúg. mankarCMnYs)as 2RbePT ³ karbþÚrRsb Edlkñúg in which a purine is substituted for enaHBuyrInmYyRtUvCMnYsedayBuyrInmYyeTot b¤BIrImIDInRtUvCMnYseday a purine or a pyrimidine for a pyrimidine; and transversions, in BIrImIDInmYyeTot nigkarbþÚrRcas;EdlkúñgenaHBuyrInRtUvCMnYsedayBIrImIDIn which a purine is substituted for a pyrimidine, or vice versa. b¤bRBa©as;mkvij. base-pairing rule : The statement ADN ARN that in DNA and RNA each base c,ab;KU)as ³ c,ab;Edl)asnImYy²kñúg nig cab;KUEtCa pairs with only one other base. mYy)asmYyepSgeTotb:ueNÑaH. basidiocarp : A reproductive structure of basidiomycetes, in )asuIdüÚkab ³ TMrg;bnþBUCrbs;)asuIdüÚmIEst EdlCakEnøg)asuIdüÚm which basidia are formed. kekIteLIg. basidiomycetes : A large and diverse group of true fungi with )asuIdüÚmIEst ³ RkumFM nigepSg²KñamYy énpSitBitedaymanGuIhVsnÞH septate hyphae; they produce basidiospores externally on basidia x½NÞ. vaplitnUv)asuIdüÚs,:enAxageRkAelI)asuIt. basidium : A club-shaped reproductive structure that forms )asIut ³ TMrg;bnþBUCragdMbgEdlbegáIts,: cMeBaHpSitmYycMnYn. spores in certain fungi. basilar membrane : A membrane in the cochlea containing sensory Pñas)at ³ PñasenAkñúgbMBg;ragKUTxügmanekasikaviBaØaN EdlRtUv cells that are stimulated by the vibrations caused by sound waves. )anePJacedaylMj½rénrlksMelg. basipetal : Toward the base. acropetal Compare acropetal . )asIueb:tal; ³ Edleq

benthic (adj) : A term used to describe organisms that live on the )atsmuRT ³ BaküeRbIsMrab;BN’naPavrs;Edlrs;enA)atsmuRT. ocean bottom. benthic zone : The floor in the sublittoral zone. tMbn;)atsmuRTrak; ³ tMbn;)atsmuRTTwkrak;²enAEk,reqñr. benthos : Organisms that live on the ocean floor. Pavrs;)atsmuRT ³ sarBagÁkay Edlrs;enA)atsmuRT. benzene : Simplest aromatic hydrocarbon. bg;Esn ³ GIuRdÚkabYGarU:m:aTicgaybMput. benzyl : Alkyl group derived from toluene by loss of a hydrogen from bg;sIul ³ RkúmGal;KIl)anmkBItUluyEGneday)at;GatUm the methyl group. GIuRdÚEsnmYyBIRkúmemTIl. beta ( βββ) decay : Radioactive decay involving emission of a beta karbMEbkebta ³ karbMEbkviTüúskmµEdlcUlrYmkñúgkarbeBa©jkaMrsIµén particle. The daughter product of a β β beta decay has one fewer neutron PaKli¥t . plitplénkarbMEbk manNWRtúgmYyticCagnigRbÚtugmYy and one more proton than the eRcInCagGIusUtUbedIm. parent isotope. beta ( βββ) particles : Negative, electron-sized particles fired out of PaKl¥itebta ³ PaKli¥tGviC¢man maDb:uneGLicRtúg EdlRtÚv)an)aj; a radioactive atom. ecjBIGatUmviTüúskmµ. beta oxidation : Metabolic pathway that oxidizes fatty acids to GuksIutkmµebta ³ clnkarénemtabUlIsEdleFVIGuksIutkmµGasIutxøaj; acetyl-CoA and reduced A coenzymes. eGayeTACaGaesTIl-kUGg;sIum nigkUGg;sIumbRgYm. beta-carotene : An orange pigment that is made of eight kar:UEtnebta ³ CatiBN’ BN’TwkRkUcEdlbgáeLIgedayÉktþaGuIsUERbn isoprene units; it occurs in most 8 plants as an accessory pigment to cMnYn . vamanenAkúñgrukçCatiPaKeRcIn EdlCaCatiBN’bnÞab;bnSMsMrab; photosynthesis. rsµIsMeyaK. beta-glucose : The form of glucose whose structure, when drawn in KøúykUsebta ³ TMrg;KøúykUsEdlTMrg;rbs;vaeBlKUrkñúgbøg;rab man flat plane, has a hydroxyl group at the first carbon that points up. RkumGuIRduksuIlmYyenAelIkabUnTImYyEdlcg¥úleLIgelI. beta-tubulin : A type of protein that is a main component of TUb‘UlInebta ³ RbUetGuInmYyRbePT EdlCaFatubgásMxan;énkUnbMBg;. microtubules. biceps : A muscle in the upper arm that moves the lower arm. It sac;dMuvavBIr ³ sac;duMm:üagsßitenAedIméd EdleFVIeGaykMPYnédman has two ‘heads’ or connecting points with bone, and forms an clna. sac;duMenHmank,al2 b¤cMnucP¢ab;BIreTAnwgq¥wg ehIybegáItCa antagonistic pair with the triceps KUbdibkçKñaCamYysac;dMuvavbI. emIlTMBr½ 326 . muscle. See p. 326. bicuspid valve : A valve in the heart between the left atrium and RbwsftelI-eRkameqVg ³ RbwskñúgebHdUgenAcenøaHftelI nigft left ventricle. eRkameqVg. biennial : A plant that grows for two growing seasons. BIrqñaM ³ rukçCatiEdlrs;)an2rdUv . bilateral symmetry (bisymmetry) : Characteristic of a body which sIuemRTIBIrxag ³ lkçN³xøÜnEdlGacRtUv)anEckCaBIresµIKña qøúHKña can be divided into mirror-image halves by a single plane of space. edaybøg;kñúglMhmYy.

bilayer : In referring to phospholipids, a bilayer is a ®sTab;eTV ³ sMedAelIpUsVrlIBIt vaCaRsTab;eTVEdlbgáeLIgeday spontaneously formed double layer of lipid, with an interior of RsTab;lIBItBIrCan; edaymanGuIRdUkabYrminRCabcitþTwkenAxagkúñg nig hydrophobic hydrocarbons and an RkumpUsVatcMNUlTwkenAEpñkxageRkA. knÞúyminEmnb:UlbegáItCasñÚlenA exterior of hydrophilic phosphate groups. The nonpolar tails form an xagkñúg ehIyRkúmk,alb:UlbegáItépÞub:Ul. interior core, and the polar head groups make the surfaces polar. bile : A substance produced by the liver that aids in the digestion of TwkRbmat; ³ sarFatuplitedayefIøm EdlCYyrMlayxøaj;. fat. bile duct : A tube that transports bile from the gall bladder to the bMBg;TwkRbmat; ³ bMBg;dwknaMTwkRbmat;BIfg;TwkRbmat;eq

biochemical reactions of photosynthesis : The reactions that RbtikmµKImICIv ³énrsµIsMeyaK ³ RbtikmµEdlBwgEp¥keTAelIsItuNðPaB depend on temperature, or “dark reactions,” of photosynthesis that ¬b¤RbtikmµvKÁggwt ¦énrsµIsMeyaK EdlbMElg]sµ½nkabUniceGayeTACa reduce carbon dioxide to kabUnGuIRdat . RbtikmµenHekIteLIgenAkúñg®sþÚm:aénkør:U)aøs . carbohydrate; occur in the stroma of chloroplasts. biochemistry : The chemistry of living things, often called KImICIv ³ ³ KImIviTüaénPavrs; eRcInehAfaKImICIvsaRsþ. biological chemistry. biodegradable (adj) : Capable of being broken down by biological GacbMEbk)anedaydMeNIrCIv ³ ³ EdlGacbMEbk)anedaydMenIrbMEbk decomposition. CIvsaRsþ. bioenergetics : Study of energy in living systems. CIvfamBlviTüa ³ karsikSaBIfamBlkñúgRbB½n§CIv³. biogenesis : The idea that all living things come from other similar kMeNItCIvit ³ KMnitEdlfa Pavrs;TaMgGs;ekItmkBIPavrs;dUcKñaepSg living things. eTot. : The study of geographic distributions of CIvPUmiviTüa ³ karsikSaBIr)ayPavrs;BIGtIt³ nig bc©úb,nñ organisms past and present, and the processes that caused these eTAtamPUmisa®sþ nig)atuPUt EdlbNþaleGaymanr)ayTaMgenH. distributions. biological clock : An internal biological timing system that naLikaCIv³ ³ RbB½n§kMNt;eBlCIvsaRsþenAxagkúñg Edlman\T§iBl influences cyclic phenomena. eTAelI)atuPUtvdþ. biological magnification : The increasing concentration of a karBRgIkCIv³ ³ karbegáInkMhab;sarFatukñúgCalika rbs;Pavrs; substance in the tissues of organisms as it is passed along in a enAeBlEdlvaqøgkat;Rcvak;cMNIGahar. food chain. biological species concept : A species consists of groups of bBaØatþBIRbePTCIvsaRsþ ³ RbePTmYy EdlmanRkuménBUkÉktþ³ actually or potentially interbreeding natural populations FmµCatiEdlGacbgáat;KñaeTAvijeTAmk ¬kñúgRbePTEtmYy ¦)an ehIyEdl that produce viable offspring GacbegáItkUnEdlmanlT§PaBlUtlas;)an. biologists : Scientists who investigate living things. CIvviTU b¤GñkCIvviTüa ³ GñkviTüasaRsþEdlsikSaRsavRCavBIPavrs;. biology : The study of living things. CIvviTüa ³ karsikSaBIPavrs;. bioluminescence : The ability of living organisms to give out light. CIvBnøW ³ lT§PaBbeBa©jBnøWrbs;Pavrs;. ]TahrN_ ³ stVGMBilGMEBk. e.g. firefly. biomass : A measure of the total mass of organic present in a büÚm:as ³ m:assrubb¤TMgn;srubénFatusrIragÁkñúgtMbn;NamYy. given area. biome : A large geographical area with characteristic life forms. e.g., tMbn;CIv ³ b¤büÚm ³ tMbn;PUmisaRsþd¾FM EdlmanTMrg;CIvitCalkçN³ tundra, tropical rain forest, marine. sMKal;. ]³ éRBTunRda éRBtMbn;RtUBic tMbn;smuRT. : The life zone of earth that includes the lower atmosphere, mNÐlCIv ³ ³ tMbn;EdlmanPavrs;rs;enA rYmmantMbn;briyakasTab land, and water to a depth of 2 kilometers. elIdI nigkñúgTwkeTAdl;CeRmABIrKILÚEm:Rt.

biosynthesis : The process of producing more complex CIvsMeyaK ³ dMeNIrplitm:UelKulEdlmanlkçN³saMjúaMCag molecules from simple ones in a living organism. BIm:UelKulsamBaØenAkñúgsarBagÁkay. : The science of gene manipulation. bec©kviTüaCIv ³ ³ viTüasaRsþEdlsikSaGMBIrebobcl½tEsn . biotic : Referring to living organisms. büÚTic ³ sMedAeTAelIPav³manCIvit . biotic community : All the populations of interactive living shKmn_büÚTic ³ b:UBuyLasüúgTaMgGs;énPavrs; EdlmanGnþr organisms sharing a common environment. TMnak;TMng nigeRbIR)as;brisßanrUmKñamYy. biotic factor : A living organism in the environment that affects ktþamanCIvit ³ Pavrs;kñúgbrisßanEdlman\T§iBleTAelIPavrs;epSg another organism. eTot. biotic potential : The highest rate of reproduction for a population skþanuBlCIv ³ ³ GRtabnþBUCx

blastula : A hollow sphere of cells that is an early stage in the )øasÞÚLa ³ sMNuMekasikaEdlmanragEsV‘RbehagkñúgéndMNak;lUtlas; development of an embryo. dMbUgrbs;GMRb‘Íy:ug. blepharoplast : A granule at the kinetosome base of a flagellum or cilium; a ebøhVar:U)aøs ³ RKab;Kl;pøaEsl rWKl;eramj½rehAfa . kinetosome. blind spot : The point where the optic nerve leaves the retina of the cMNucxVak; ³ cMnucEdlsrésRbsaTGubTicecjBIerTIn. vaKµanekasika eye. It does not have rod or cone cells and so cannot respond to ragdMbg b¤ekaneLIy dUecñHehIyeTIbvaKµankareqøIytbeTAnwgBnøWeT. light. blood : A liquid composed mainly of plasma (water, ions, proteins, Qam ³ sarFaturavbgáeLIgCasMxan;eday)aøsµa ¬Twk-GIuy:ug-RbUetGIun fibrin and clotting factors), blood cells (leukocytes and erythrocytes) PIRb‘Ín-ktþakk ¦ ekasikaQam ¬eKalikas nig eKalikaRkhm¦ nig and platelets. It transports nutrients )øaEkt. vadwknaMsarFatuciBa©wm ¬GasIutGamIen KøúykUs GuksIuEsn (amino acids, glucose, oxygen, lipids), cell wastes (urea, carbon niglIBIt ¦ sMNl;BIekasika ¬G‘uyer: ]sµ½nkabUnic kMedA ¦Grm:Un nigFatu dioxide, heat), hormones and parts of the immune system, to and from énRbB½n§bnSúMa rWRbB½n§karBareTAekasikarWBIekasika. cells. blood grouping : A method of describing blood from different karcat;RkumQam ³ vIFIénkarBiN’naGMBIQamEdl)anmkBImnusS individuals by the presence or absence of antigens on their red epSg²Kña edayEp¥keTAelIvtþman rWGvtþmanénGg;TIEsnenAkñúgeKalika blood cells. See ABO blood Rkhm. emIl ABO blood groups , rhesus blood groups, Lutheran blood groups, rhesus blood groups, Lutheran blood groups. groups . bloom : 1- A rapid increase in the number of microorganisms in a 1- kMeNIty:agrh½s ³ karekIneLIgy:agelOnnUvcMnYn body of water. 2- Flower. mIRkUsarBagÁkaykñúgTwk . 2- rIky:agrh½s ¬páa¦. blowout : An area of exposed soil caused by ripping out part of tMbn;valedayxül; ³ tMbn;dIval EdlbNþalmkBIxül;bk;yk the vegetation cover rukçCatieTA)at;. blubber : A thick layer of fat in some aquatic mammals. eg whale. RsTab;xøaj; ³ RsTab;xøaj;Rkas;rbs;fnikstVrs;enAkñúgTwkmYycMnYn. ]TahrN_ ³ RtI)aELn. body cell : One of two cells produced when the generative cell ekasikaem ³ ekasikamYykúñgcMeNamekasikaBIr EdlbegáIteLIgenA of a gymnosperm male gametophyte divides; the body cell eBlEdlekasikabgákMeNIténkaEm:ttUPIteQµalrbs;suImNUEs

Bohr’s planetary electron model: Bohr Niels Bohr Model proposed by Niels Bohr KMrUeGLicRtugPB ³ KMrUesñIeLIgeday Edlpþl; suggesting that electrons rotate around a nucleus in a set of fixed eyabl;faeGLicRtugvilCMuvIjéNVy:UkñúgKnøg nwgdUcCaPBTaMgLay orbits like planets around the sun. enACMuvijRBHGaTitü. KMrUenHkNt;Camunfa BnøWRtÚv)anbeBa©jenAeBl The model predicts that light is given off when electrons jump eGLicRtúgelatecjBIKnøgxageRkAeTAKnøgxagkñúg. from outer orbits to inner orbits. boiling point : Temperature at which a substance in the liquid kMritBuH ³ sItuNðPaBEdlsarFatukñúgsPaBrav )anbMElgCasPaB]sµ½n state is converted to the gaseous state. The gaseous form of the ehIyTMrg;]sµ½nénsarFatuenaHeFVIkugdg;kmµeTACaravenAsItuNðPaB substance condenses into a liquid dEdl. at the same temperature. bond strength : Ability of one atom to hold onto another. Stronger kMlaMgsm<½n§ ³ lT§PaBénGatUmmYyEdlcab;ykGatUmepSgeTot. sm<½n§ bonds hold atoms together more tightly, resulting in higher melting kan;EtxøaMg CMnab;GatUmCamYyKñakan;EtmaM naMeGaycMNucrlayrbs; points for their compounds. smasFatumankMritkan;Etx

brain : Collection of neurons located at the anterior (front) end xYrk,al ³ bNþMúNWr:UnÉkeTssßitenAEpñkxagmux EdledIrtYCa of an animal that acts as a control center for body processes. mCÄmNÐlRtYtBinitüdMeNIrRbBwtþeTAénsarBagÁkay. branch root : A root that grows from an older root. rwsryagx©I ³ rwssEdlduHecjBIrwscas;². branchial : Relating to the gills. eRbnexol ³ EdlTak;TgeTAnwgRskI. branchiomeric : Segmentation of structures associated with, or eRbnXIGUmWrik ³ TMrg;x½NÐCaGgát;EdlTak;TgeTAnwgrWEdlmanRbPBmk derived from, the ancestral Metameric pharyngeal arches. See metameric . BIFñÚRskIedImkénbuBV. emIl . BrdU (5-bromodeoxyuridine) : An analogue of thymidine in which 5-RbUmU:edGuksuIGu‘yrIDIn ³ FatuRsedogKñanwgTImIDIn EdlkñúgenaHRkum the methyl group at the 5’ position 5’ (Br) in thymine is replaced by bromine. emTIlenARtg;TItaMg énTImInRtUv)anCMnYsedayRbUm . vaGac It can cause mutations. bNþaleGaymanmuytasüúg. breathing : The process of pumping air in and out of the kardkdegðIm ³ dMenIrxül;bWtxül;cUlnigecjBIsYt. lungs. breathing center : A part of the medulla oblongata that controls mCÄmNÐldegðIm ³ EpñkmYyrbs;xYrkBa©wgk EdlRtYtBinitüdegðIm. breathing. bronchiole : Tiny branches of the bronchi in the lungs. kUnTgsYt ³ EmktUc²rbs;TgsYtenAkñúgsYt. bronchus (pl. bronchi) : One of the two large tubes branching from TgsYt ³ bMBg;mYykñúgcMenambMBg;FM²BIrEdlEbkEmkBIbMBg;xül;. the trachea. Bronsted-lowry model for an Bronsted-lowry acid : Theory that defines an acid KMrU sMrab;GasIut ³ RTwsþIEdlkMnt;faGasIutCasarFatu as a substance that can donate a proton . The proton acceptor is GaceGayRbÚtug. GñkTTYlRbÚtugmaneQµaHfa)as. called a base. brood patch : An area of enlarged blood vessels in a bird’s chest that kEnøgpþl;kMedA ³ tMbn;srésQamrIkFM²enAnwgRTUgbkSI Edlman functions during incubation for warmth. muxgarpþl;kMedAenAeBlRkabBg. brooding : Parental care of developing young. karEfTaM ³ karEfTaMkUnEdlkMBuglUtlas;edayem)a. Brownian motion : Constant, Brown random motion characteristic of clna ³ clnaefr nigécdnüEdlCalkçN³énPaKl¥itvilvl;kñúg colloidally suspended particles. sUluysüúgkULÚGIut. bryophyte : Member of a division of nonvascular Plants; the mosses, Rb‘Íy:UPIt ³ smaCikénsaxamYyrbs;rukçCatiKµansrésnaMrYmmanEsø hornworts, and liverworts hornworts nig liverworts . BSE : See Bovine Spongiform Bovine Spongiform Encephalopathy Encephalopathy CMgWeKaqáÜt ³ emIl . bud scale : A small thick modified leaf that protects a bud. søwkBnøk ³ søwkkMENERbtUc-Rkas; EdlkarBarBnøkRtYy. budding : A form of asexual reproduction in which new karecjBnøk ³ TMrg;énkarbnþBUC\tePTEdlÉktá³fµIduHlUt-las;ecj individuals develop from a part of (Bryozoa) the parent in all bryozoans and in BIEpñkmYyénem)a dUcCacMeBaHRb‘Íy:UsUEG‘ TaMgGs; RbÚtUsUEG‘Ca many protozoans, cnidarians and eRcIn KñIED (Cnidaria) nigdgáÚvxøÜnkg;maneramsURteRcIn. RbePTénkar polychaetes. A type of grafting in which the scion is a bud. bMe)Am:üagEdlExñgbMe)AKWCaBnøk.

buffer : Mixture of roughly equal parts weak acid and the salt of the tMb:ug ³ l,ayénPaKesµIKñarvagGasIutexSaynigGMbilrbs;GasIutenaH acid (its conjugate base) whose pH pH changes little when small amounts ¬)asrbs;va ¦Edl rbs;vaERbRbÜlticenA eBlbEnßmbrimaNtictYc of either acid or base are added. énGasIutrW)aseTAkñúgl,ay. bulb : A short, underground stem surrounded by many fleshy leaves. emImRsTab; ³ edImeRkamdIxøI² EdlB½T§CMuvijedaysøwksac;y:ageRcIn. eg Onion. ]> emImxÞwm)araMg. bulimia : A nutritional deficiency disease characterized by a b‘uylImI ³CMgWxVHsarFatuciBa©wmEdlsMKal;edaykarhUby:ageRcIn binge-and-purge cycle of eating. It is thought to stem from ehIybeBa©jecalvijPøam. eKKitfaCMgWenHbNþalmkBIvibtþipøÚvcitþ. psychological disorders. bulliform cells : Large epidermal cells that occur in groups on the ekasikaragBBuH ³ ekasikaeGBIEDmFM² EdlmanenACaRkumelIEpñkxag upper surface of leaves of many grasses; loss of turgor pressure in elIénsøwkrbs;BYkesµAPaKeRcIn. kar)at;bg;sMBaFe)a:genAkúñgekasika these cells causes leaves to roll up TaMgenH bNþaleGaysøwkrmYrkúñgkMLúgeBlxVHCatiTwk. during water stress. bundle sheath : A layer of tightly packed cells around a leaf vein. in eRsam rWPñasEv:n ³ RsTab;ekasikatMeroby:agENnmYyRsTab;Edl C4 plants, the bundle sheath is C4 photosynthetic and prominent B½T§CuMvijEv:nsøwk. cMeBaHrukçCati eRsam)ac;srésenHeFVIrsµIsMeyaK ehIylyecjmkeRkA . buoyant density : A property of particles (and molecules) that dg;suIetvtßúrav ³ lkçN³énPaKl¥it ¬nigmU:elKul ¦EdlGaRs½yelI depends upon their actual density, as determined by partial specific dg;suIetBitR)akdrbs;va dUcEdl)ankMnt;edaycMNuHyfaRbePTeday volume and degree of hydration. Epñk nigkMriténGuIRdatkmµ. vapþl;CamUldæanRKwHsMrab;karEjkCMralkMhab; Provides the basis for density gradient separation of molecules or rvagmU:elKul b¤PaKl¥it. particles. C C horizon (parent material) : The C B layer of soil between bedrock and RsTab; ¬sarFatuem¦ ³ RsTab;dIcenøaHkMralfµ nigRsTab; . the B horizon. It varies in thickness between about 10 centimeters and kMras;vaERbRbYlBI10s>meTABIr-bIEm:Rt b¤CYnkalGacKµanRsTab;eT. several meters, or it may be absent C3 plant : Plant in which the first C3 Calvin fixation of carbon is via the Calvin rukçCati ³³³ rukçCatiEEdlCMnab;TImYyénkabUn KWtamvdþ . cycle. The first stable product of photosynthesis is a three carbon plitplesßrPaBdMbUgénrsµIsMeyaK KWsmasFatukabUn3. compound. See p. 330. emIlTMBr½330 . C4 plant : Plant (eg corn) in which C4 the first fixation of carbon rukçCati ³³³ rukçCati ¬]>eBat ¦EdlCMnab;TImYyénkabUn plitGasuIt produces a four-carbon acid. C4 kabUn4. rukçCati C4 GacP¢ab;CO 2enAkEnøgNaEdlmankMhab;Tab plants can fix CO 2 in places where the concentration is low eg ]> éRBtMbn;RtUBic. emIlTMBr½ 330 . Tropical forests. See p. 330. CAAT box : A DNA sequence that CAAT ADN is similar in different organisms RbGb ; ; ³ tMnlMdab; EdlRsedogKñakñúgPavrs;epSg²Kña found about 75 base pairs 5’ to the ‘ site of transcription in eukaryotic nigmanRbEhl75KU)asRtg; 5 enAkEnøgcMlgRkménEsnGWkarIyU:t. genes.

Caccum (pl.cacca) : Pouches branching from the stomach in fñk;RkBH ³ fg;EbkecjBIRkBHstVl¥it. insects. caenogenesis : In the development of an organism, the new stages that XINUeCnensIus ³ enAkñúgkarlUtlas;rbs;Pavrs; dMNak;fµIEdl have arisen in adaptive response to the embryonic mode of life, such elceLIgenAkñúgkarbnSaMueTAnwgrebobrs;enArbs;GMRb‘Íyu:g dUcCaPñasTwk- as the fetal membranes of ePøaHénKP’. amniotes. callose : A complex carbohydrate in sieve tubes of sieve tube kal;LÚs ³ kabUnGuIRdatsaMjauM enAkúñgbMBg;RbehagénFatubMBg; members; callose is especially abundant in injured sieve tubes. Rbehag. vamaneRcInCaBiessenAkúñgbMBg;RbehagEdlmanrbYs ¬xUcxat ¦. calmodulin : enzymes in membranes; as much as 2% of the kalm:UDuylIn ³ Gg;suImenAkñúgPñasekasika. RbEhl plasma membrane may be calmodulin. 2PaKryénPñas)aøsµa GacCakalm:UDuylIn. calorie (cal) : 1. A unit of heat; (cal) one calorie is the amount of heat kaLÚrI ³ 1- ÉktaénkMedA . mYykaLÚrI KWCabrimaNkMedAEdl®tUv required to raise the temperature of (1 = 4.12 J) 1 g of water1 oC; 1 cal = 4.12 J. karedIm,IbegáInsItuNðPaB1GgSaresénTwk1Rkam. kaLÚrI . 2. © Unit of energy used in 2- © ÉktaénfamBlEdleRbIkñúgcMNIGahar. vaesµInwgmYyKILÚkaLÚrI . It is equal to 1 kcal or 1000 “small” calories. rWmYyBan;kaLÚrI. Calvin cycle : Series of enzymatic Calvin ³ es‘rIénRbtikmµGg;suImEdlkúñgenaH CO 2 ®tUv)anbnßy reactions in which CO 2 is reduced vdþ to 3phospho-glyceraldehyde (a three-carbon compound) and the eTACaKøIesr:al;edGuIt-3-pUsVat ¬smasFatuEdlmankabUn 3 ¦ ehIy CO 2 acceptor (ribulose, 1,5-bis- GñkTTYl CO 2 (ribulose, 1,5-bisphosphate) ®tUv)anbegáIteLIgvij. phosphate) is regenerated. calyptra : The covering that partially or entirely covers the kalIbRta ³ KMrbEdlRKbmYyPaK b¤RKbTaMgRsugBIelIkab;s‘ulrbs; capsule of some species of mosses. RbePTésømYycMnYn . calyx : A group of specialised leaves that surround the flower . kB©aMúRtbk ³ RkumsøwkbMElgÉkeTsenACuMvijpáa. CAM : see Crassulacean Acid CAM Crassulacean Acid Metabolism Metabolism ³ emIl . cambium : A tissue in higher plants that produces new xylem kMbüÚm rWRsTab;emkñúg ³ Calikarbs;rukçCatifñak;x

canonical sequence : See consensus sequence consensus sequence. lMdab;tamlMnaM ³ emIl . canopy : The leafy covering of a forest provided by the tallest trees. éRBdMbUl ³ KMrbsøwkRtQwgRtéQénedImeQIx

carbonyl : Family of organic compounds composed of a carbon kabUnIl ³ GMbUrénsmasFatusrIragÁEdlmansm<½n§BIrCan;rvag double-bonded to an oxygen. The two remaining carbon bonds may kabUnnigGuksIuEsn. sm<½n§BIreTotrbs;kabUnEdlenAsl;RtÚv be connected to other atoms or cgP¢ab;eTAnwgGatUmdéT rWRkúmGal;KIl. alkyl groups. carbonyl group : Functional group characterized by a carbon oxygen RkúmkabUnIl ³ bgÁMúmuxgarsMKal;edaysm<½n§BIrCan;rvagkabUn nig double bond. GuksIuEsn. C = O carboxyl group : Group of atoms composed of a carbonyl group with RkúmkabuksIul ³ RkúmGatUmEdlmanRkúmkarbUnIlCamYynwg an—OH connected to one of the free carbon bonds. Carboxyls are GIuRdúksIulP¢ab;eTAnwgsm<½n§TMenrrbs;kabUnmYy . karbuksIul the characteristic group of organic CaRkúmbgðajlkçN³GasIutsrIragÁ. C = O acids. OH carboxylate anion : Resonance- stabilized anion resulting from Gaj:ugkabuksIuLat ³ Gaj:úgmansßirPaBénersUNg; Edl)anmkBIkar removal of the acid proton of an C = O organic acid. )anBIkarpþac;RbÚtugGasIuténGasIutsrIragÁ. O - carboxylic acid : Organic compound containing one or more GasIutkabuksIulic ³ smasFatusrIragÁEdlmanRkúmkabuksIulmYy carboxyl groups. rWeRcIn. R C = O OH carcinogen : A physical or chemical agent that causes cancer. Pñak;garmharIk ³ Pñak;garrUb b¤KImIEdlbNþaleGayekItCMgWmharIk. carcinogenic (adj) : Capable of inducing the formation of cancer GacekItmharIk ³ PaBEdlGacbNþaleGaymankarkekItekasika cells. mharIk. cardiac muscle : The muscle that makes up the heart in vertebrates. sac;dMuebHdUg ³ sac;duMEdlbgáCaebHdUgénstVq¥wgkg. sac;duMenHman It has some characteristics of striated muscle (its fibres are lkçN³xøHCasac;dMuqñÚt ¬srésrbs;vaqñÚt ¦ ehIylkçN³xøHCasac;duM striated), and some characteristics rlIg ¬ sac;duMenHminmankarenOyht;eT bnÞab;BImanrMejacdEdl² of smooth muscle (it does not become tired after repeated ehIyekasikanImYy²manéNVyU:EtmYyKt; ¦. stimulation, and each cell has only a single nucleus). carnivore : An animal that eats other animals for food. mMsasI ³ stVEdlsIustVepSg²eTotCaGahar. carotenoid : Any compound in a class of yellow, orange, or red kar:UetNUGIut ³ smasFatuEdlzitkñúgfñak;énCatiBN’bnÞab;bnSMGac fat-soluble accessory pigments that are derived from eight isoprene rlaykñúgxøaj; BN’Rkhm TwkRkUc b¤elOg EdlmanRbPBmkBIÉkta units linked together; the most GuIsUERbncMnYn8Cab;Kña. kar:UetNUGIutkñúgrukçCati EdleRcInCageKKW β- widespread carotenoid in plants is beta-carotene. kar:UEtn. carpel or pistil : The female reproductive structure of a flower kBa©úMeksrjI rWBIsÞIl ³ TMrg;bnþBUCjIrbs;páa EdlmanGUEvmYy keksrjI made from a single ovary, style, and stigma. nigsÞIcm:at. carpellate flower : A flower Monoecious whose reproductive parts consist páajI ³ páaEdlEpñkbnþBUCrbs;vamanEteksrjI. emIl . only of carpels. See Monoecious.

carpellate plant : An individual plant whose flowers bear carpels rukçCatijI ³ rukçCatimYyedImEdlmanEtpáajI KWpáarbs;vamanEtkBa©úMeksr but not stamens; a fruiting mulberry is an example of a plant jI KµaneksreQµaleT. edImetñatjIKW]TahrN_mYyEdlCarukçCatimanEt that is exclusively carpellate páajITaMgRsug GacbegáItEpøEdlGaclUtlas;)anenAeBlEdlRKab;lMGg (mulberries can form fertile fruits only when pollen is transferred ®tUv)andwknaMBIrukçCatimaneksreQµaleTAkan;rukçCatiEdlmaneksrjI ¦. from a staminate plant to a carpellate plant) See dioecious. emIl dioecious . carrageenan : A slimy polysaccharide, consisting mostly xar:aCINan; ³ b:UlIsakarItragxab;Gn§il EdlmanpÞúkPaKeRcInUvl,ay of a specific mixture of alpha- galactose sulfates that surround the Gal;hVakaLak;tUssu‘lpat EdlB½n§CMuvijPñaseRKagénsarayRkhmmYy cell walls of certain red algae; the cMnYn. RbPBBaNiCkmµd¾sMxan;én carrageenan KWRbePTénBUk main commercial sources of are species of the genus Chondrus. Chondrus . carrier : 1- An individual that is 1- heterozygous for a recessive trait. GñkpÞúk rWGñkdwknaM ³ Éktþ³eGetrU:suIkUt sMrab;lkçN³Gn;. 2- Person infected with a disease 2- but does not show symptom. GñkpÞúkCMgW ³ GñkEdlrgkarbgáCMgW b:uEnþminelcecjnUveraKsBaaØ. carrion flower : A type of flower carrion that is foul smelling (carrion odor) páakøins¥úy ³ páamYyRbePTEdlmankøinGaRkk; ¬køin ¦ehIy and attracts flies or beetles as pollinators. Tak;TajstVruy b¤stVGeNIþkmasCaGñkdwknaMRKab;lMGg. carrying capacity : The limit at which the environment can support smtßPaBRTRTg; ³ kMritEdlbrisßanGacRTRTg;b:UBuyLasüúgmYy a certain population. cMnYn. cartilage : A specialised connective tissue that is strong but q¥wgx©I ³ Calikasn§anbMElgÉkeTs EdlrwgmaMb:uEnþTn;Pøn; nigbgáCa flexible and composes some part of the endoskeleton in all vertebrates. eRKagq¥wgxagkñúg cMeBaHstVq¥wgkgTaMgGs;. caryopsis : A dry fruit whose ovary wall is joined to the seed EpøRKab;sac; ³ EpørukçCatis¶ÜtEdlépÞrbs;GUEvP¢ab;eTAnwgsMbkRKab;. coat. eg. cereal grains. ]TahrN_ RKab;FBaØCati. casparian strip : The waterproof layer covering the side and end bnÞHkas,:arI ³ RsTab;minRCabTwkEdlRKbBIelIekasikaGg;dUEDménrws. walls of endodermal root cells. catabolism : The chemical reactions that break down large Gsmankmµ/ katabUlIs ³ RbtikmµKImIEdlbMEbkm:UelKulFM²eGay molecules into smaller molecules with the release of energy. eTACam:UelKultUc² edaybeBa©jfamBl. catabolite activator protein : See CAP CAP . emIl . catabolite repression : The selective inactivation of an operon karTb;katabUlIt ³ skmµkmµEdl)aneRCIserIsénGUeb:ru:geday by a metabolic product of the enzymes encoded by the operon. plitplemtabUlIsénGg;suImEdlcMlgRkmGUeb:ru:g. catadromous : Migrating down a river or stream to a lake or ocean to pøas;lMenAcuHBg ³ bMlas;lMenABIsÞwgrWTenøeTAbwgrWsmuRTedIm,IBg spawn (of fishes). See anadromous. ¬RtI ¦. emIl anadromous . catalyst : Compound that increases the rate of a reaction. It makes katalIkr ³ smasFatuEdlbegáInel,ÓnRbtikmµ.vaeFVIeGayRbtikmµ reactions faster by providing an alternative reaction pathway with ekInelOnedaykarpþl;clnkarRbtikmµqøas; EdlmanfamBlskmµkmµ lower activation energy. The TabCag. katalIkrminRtÚv)anbMpøajeTenAkñúgRbtikmµ. catalyst is not destroyed in the reaction.

catastrophism : The concept that geologic changes result from RTwsþImhnþray ³ KMnitEdlfa karERb®bYlFrNIKWCalT§plén sudden, violent, large-scale, worldwide catastrophic events RBwtiþkarN_mhnþrayBaseBjBiPBelak RTg;RTayFM-xøaMgkøa nigrh½s. cathode ray : Particles of negative electricity traveling through a kaMrsµIkatUt ³ PaKl¥itEdlmanbnÞúkGKÁIsnIGviC¢manqøgkat;tambMBg; vacuum tube, from cathode to anode. We know cathode rays suBaØakasBIkatUteTAGaNUt. bc©úb,nñenHeyIgdwgfakaMrsµIkatUtCa)ac;BnøW today as the beam that sweeps Edlrt;kat;muxGMBUlTUrTsSn_edIm,IbegáItCarUbPaB. across the face of a television tube to produce the picture. cation : A positively charged ion. kacug ³ GuIyu:gEdlmanbnÞúkGKÁisnIviC¢man. caudal fin : A single fin located on the tail of a bony fish. RBuyknÞúy ³ RBúyeTalsßitenAnwgknÞúyRtIq¥wg. cdc mutation : A class of cdc mutations in yeast that affect the muytasüúg ³ fñak;mYyénmuytasüúgkñúgemnMbu½gEdlman\T§iBl timing and progression through the cell cycle. eTAelIkarkMNt;eBlevla nigdMeNIrvivDÆn_tamqøgkat;vdþekasika. cDNA : See complementary cDNA : complementary DNA DNA. emIl . cell : Basic structural unit of life; the smallest part of a living ekasika ³ ÉktaTMrg;RKwHénCIvit. EpñktUcbMputrbs;Pavrs;EdlGac organism that can carry out life processes by itself. dMeNIrCIvit)anedayxøÜnÉg. cell cycle : Sum of the phases of growth of an individual cell type; vdþekasika ³ cMnYnsrubénvKÁlUtlas;rbs;RbePTekasika. vdþenH divided into G 1 (gap 1), S (DNA EckecjCavKÁG1 ¬gap1 ¦ vKÁ S ¬sMeyaK ADN ¦ vKÁ G 2 ( gap 2 ) nig M synthesis), G 2 (gap 2), and M (mitosis). ¬mItUs ¦. cell fractionation : The isolation of different organelles or parts of karEjkekasika ³karEjkecjBIKñaénFatuekasika b¤Epñkénekasika cells by centrifuging a homogenized cell extract in a edaykarbgVilRbTajecjnUvsarFatuesµIsac;cMraj;ecjBIekasikaeTA concentration gradient of, for tamlMdab;kMritkMhab;sakar:UsCa]TahrN_. example, sucrose. cell membrane : The outer boundary membrane of the cell Pñasekasika ³ Pñasx½NÐxageRkArbs;ekasikaEdlpSMeLIgBIpUsVrlIBIt composed of phospholipids and proteins. Some of the proteins have nigRbUetGIun. RbUetGIunmYycMnYn)anP¢ab;eTAnwgkabUGIuRdatb¤xøaj;. eKk¾ attached carbohydrates or fats; ehAvapgEdrfaPñas)øasµa b¤PñassIutU)øas. also known as the plasma membrane. cell plate : The disk-shaped structure that forms from the fusion bnÞHekasika ³ TMrg;manragCafas EdlekIteLigBIkarrlaycUlKñaén of vesicles at the equator of the spindle apparatus during early fg;enAelIGk½SeGkVaT½rénRty:UgGaRkUm:aTic kñúgedImvKÁetLÚpascMeBaH telophase in plants and some algae; rukçCati nigsaraymYycMnYn. eBleBjv½ybnÞHekasikaenHkøayCa when mature, the cell plate becomes the middle lamella. bnÞHesþIgkNþal . cell wall : Rigid structure that surrounds bacterial and plant cells. PñasEsluyLÚs ³ PñaseRKagrwgrMuBT½§CMuvijekasika)ak;etrI nigrukçCati. It protects the cell from rupturing in hypotonic solutions. vakarBarekasikaBIkarpÞúHEbkkñúgsUluysüúgGIub:UtUnic.

cell-free extract : A preparation of the soluble fraction of cells, made sMrg;Kµanekasika ³ karerobcMEpñkrlayénekasika EdlbegáIteday by lysine cells and removing the solid particles, such as nuclei, ekasikalIsuIn nigkarykecjEpñkrwg dUcCaéNVyU: PñasnigFatuekasika. membranes, and organelles. Often viFIenHRtUv)aneKeRbICajwkjab;enAkñúgkarkarsMeyaKRbUetGuIn edaykar used to carry out the synthesis of proteins by the addition of specific, bEnßmmU:elKul ARN m yfaRbePT. extra mRNA molecules. cellular respiration : The process of converting food energy into a degðImekasika ³ dMenIrbMElgfamBlcMNIGahareGayeTACaTMrg;mYy form usable by cells that takes place in the mitochondria. EdlGaceRbIR)as;)anedayekasikaEdlRbRBwtþeTAenAkñúgmItUkugRDI. cellulase : An enzyme that breaks down cellulose into smaller units EsluyLas ³ Gg;suImEdlbMEbkEsluyLÜseGayeTACaÉktatUc² by cleaving the 1,4 linkages 1,4 β between molecules of beta-glucose. edaypþac;cMNg rvagm:UelKul -KøúykUs. cellulose : Plant polysaccharide β 1,4 made up of β 1,4 linked glucose. EsluyLÚs ³ b:UlIsak;karItrukçCatibgáeLIgBIsm<½n§ P¢ab;KøúykUs. The structural material in plants. KWCasarFatueRKagrbs;rukçCati. Celsius scale : Temperature scale Celsius used worldwide in which water maRtdæan ³ xñatsItuNðPaBEdlRtÚv)aneRbIR)as; o o freezes at 0 C and boils at 100 C. TUTaMgBiPBelak KWTwk kkenA 0oC nigBuHenA 100 oC. cementum : A hard layer of material just under the enamel of a sMbkrwseFµj ³ RsTab;rwgénsarFatuEdlsißtenACab;xageRkam tooth. kacaeFµj. CEN : In yeast, fragments of CEN ADN chromosomal DNA, about 120 bp ³ cMeBaHemnMb½ug vaCaGgát; kñúgRkUmU:sUm manRbEvgRbEhl long. When inserted into plasmids 120KU)as. enAeBldak;bBa©Úlkñúg)aøsµIt vanwgmanlT§PaBEjkdac; they give the ability to segregate during mitosis. These segments edayELkkñúgkMLúgeBlmItUs. Ggát;TaMgenHya:gehacNas;k¾man contain at least three types of sequence elements associated with tMnlMdab;3RbePTEdr EdlmanTMnak;TMngCamYynwgmuxgarsg;RtUEm. centromere function. Cenozoic : The geological era from the Mesozoic to the present esNUsUGiuc ³ s½kPUKBÖsaRsþ cab;BIs½kemsUsUGuicmkdl;bc©úb,nñ (about 65 million years). See p. 320 320 ¬RbEhl 65 lanqñaM¦. emIlTMBr½ . centimeter (cm) : Metric unit of 1/100 m length equal to 1/100 m (the sg;TIEm:t ³ xñatRbEvgCaEm:tesµInwg ¬buBVbTsg;TImann½yfa decimal prefix centi- means times 1/100 1/100). KuNnwg ¦. centimorgan : A unit of distance between genes on chromosomes. sg;TImr½kg; ³ xñatcMgayrvagEsnenAelIRkUmU:sUm. mYysg;TImr½kg; One centimorgan represents a value of 1 percent crossing over tageGaytMélRkUsuIgGUevI1 °rvagEsn2. between two genes. central dogma : The concept that ADN ARN information flow progresses from bBaØtþRKwH ³bBaØtEdlfa mankarbBa©ÚnBt’manBI eTA nigeTA DNA to RNA to proteins. Although exceptions are known, RbUetGuIn. eTaHbICamankarelIkElgk¾eday k¾KMnitenHCamUldæany:ag this idea is central to an under- sMxan;karEsVgyl;BImuxgarEsn. standing of gene function. central nervous system : The brain and spinal chord. RbB½n§mCÄmNÐlRbsaT ³ xYrk,alnigxYrq¥wgxñg. central placentation : Refers to the attachment of ovules along the CMnab;GUvulkNþal ³ sMedAeTAelIkarP¢ab;rbs;GuvultambeNþay central axis of an ovary that has just one ovule-bearing chamber bNþÚlGk½SkNþalénGUEv EdlmanftEtmYy.

centric fusion : See Robertsonian Robertsonian translocation translocation. CMnab;kNþal ³ emIl . centriole : A cylindrical organelle near the nucleus during inter-phase sg;RTIy:Ul ³ FatuekasikaragsuILaMg sßitenACitéNVy:UenAcenøaHvKÁ that moves to the spinal poles during mitosis. Usually found in ehIyeFVIdMeNIreTAb:UlenAeBlmItUs. eRcInRbT³eXIjenAkñúgsg;RtUsUm the centrosome and considered to nigRtÚv)ancat;TukCamCÆmNÐlskmµéncMENkekasika. be the active division center of the cell. centromere : The region where two chromatids are joined and sg;RtÚEm ³ kEnøgEdlRkUm:aTItTaMg2P¢ab;Kña nigRtUv)anP¢ab;eTA attached to a spindle fiber. nwgsrésGaRkUma:Tic. centrosome : Region of the cytoplasm containing the centriole. sg;RtUsUm ³ tMbn;énsuItU)øasEdlmansg;RTIyU:l. centrum : Vertebral element formed in or around the notochord tYq¥wgkg ³ Fatuq¥wgkgEdlkekIteLIgkñúgrWCMuvijBYrq¥wgxñg (plural, centra). ¬Bhuvcn³ Centra) . cephalic : Relating to the head. k,al ³ EdlTak;TgeTAnwgk,al. cephalisation : A trend in animal evolution toward larger brains and vivtþn_xYrk,al ³ karvivtþn_rbs;xYrk,alkan;EtFMeTA² nigkan;Etman more complex senses in the head. viBaØaNsµúKsµajCagenAkñúgk,al. cephalothorax : One of two main body parts in some arthropods k,alRTÚg ³ EpñkmYyénEpñksMxan;TaMgBIrrbs;GakRtUb:UtmYycMnYn made of a fused head and thorax. EdlekIt eLIgBIkarrlaycUlKñaénk,alnigRTUg. ceratotrichia : Keratin fibers that support the web of the fins of esr:atURTIs ³ srésekra:TInEdlRTRTg;bNþajRBuyRtIq¥wgx©I. chondrichthyes. cerebellum : The region of the brain lying below the cerebrum and xYrtUc ³ tMbn;xYrk,alenAxageRkamGDÆeKalxYrnigxagelITgxYr Edl above the pons that controls muscular coordination and balance. RtYtBinitüclnasac;duMniglMnwg. cerebrospinal fluid : A fluid in the brain and spinal cord that cushions TwkxYr ³ sarFaturavkñúgxYrk,alnigxYrq¥wgxñg EdlkarBarvaTb;Tl;nwg them against shock. karb:HTgÁic. cerebrum : The largest part of the human brain that is the control area GDÆeKalxYr ³ EpñkFMbMputénxYrk,almnusSEdlCatMbn;RtYtBinitükar for reasoning, memory, and voluntary nervous activity. KitBicarNa karcgcaM nigskmµPaBRbsaTedayectna. cervix : A muscular ring of tissue at the place where the uterus and ks,Ún ³ Calikasac;duMkg EdlCakEnøgCYbKñarvags,Ún nigpøÚveyanI. vagina join. chain reaction : Series of very rapid reactions that occur among RbtikmµCaes‘rI ³ es‘rIénRbtikmµelOnbMputEdlekIteLIgkñúgeBlbMEbk fissionable atoms if they are close enough together. The products of GatUm ebIsinCavaenACitKña. lT§plénRbtikmµnimYy²bNþaleGayman each reaction cause several other RbtikmµepSg²eTotekIteLIg ehIyGRtaénRbtikmµenHekIneLIgCalMdab;. reactions to occur so that reaction rate accelerates.

chalaza : 1. the base of the ovule in a flowering plant to which the kaLas ³ 1- EpñkxagKl;énGUvulcMeBaHrukçCatimanpáa EdlCakEnøg funicle is attached, and through which the pollen tube sometimes TgGUvul®tUv)anP¢ab; nigCYnkalCakEnøgEdlbMBg;lMGgcUleTAkñúgGUvul enters the ovule prior to munkarbgákMeNIt. 2- bnÞ³rages<órmçagkñúgEpñksrbs;s‘utbkSI vaeFVI fertilization. 2. one of the opposite pair of spiral bands in the white of eGayEpñkelOgGENþtkñúgsMbknigkarBarkMueGaymankarxUcxat. a bird’s egg which suspend the yolk within the shell to prevent it from being damaged. chaparral : A type of vegetation with low shrubs that have thick éRBKuem

chemical periodicity : Cyclic or periodic repeating of chemical and xYbénFatuKImI ³ vdþrWxYbénlkçN³KImIniglkçN³rUbrbs;FatuKImICamYy physical properties with increasing atomic weight caused by the kMenInma:sGatUm EdlbNþalmkBIkartMerobeGLicRtúgCMuvijGatUm. arrangement of electrons around atoms. chemical reaction : A reaction where bonds between atoms are RbtikmµKImI ³ RbtikmµEdlsm<½n§rvagGatUmRtUv)ankat;pþac; rWbegáIteLIg. broken or formed. chemical symbol : A one or two letter abbreviation used to nimitþsBaØaKImI ³ GkSrkat;mYytY rWBIrtY EdleRbIsMrab;tageGayFatu represent each of the elements. nImYy². chemiosmotic theory : Theory stating that the energy released by RTwsþIKImIGUsµÚs ³ RTwsþIEdlEcgfafamBlEdlRtUv)anrMedaHedaykarepÞr the flow of electrons along the electron-transport chain is used to eGLicRtúg tamExSdwkbBa¢ÚneGLicRtúgRtÚv)aneRbIR)as;edIm,IbegIátlMdab; establish a proton gradient. This kMritRbÚtug. famBlx ¦ ³ ExSKgExVgKñaénRkUma:TItminEmnbgb¥Ún emIl chromatids seen in diplotene of the I first meiotic division. Regarded as eXIjkñúgvKÁDIbøÚEtnéncMENkemyU:s . va®tUv)aneKcat;TukCaPsþútag the cytological evidence for ekasikaviTüaEdlbgðajBIkarbþÚrsMPar³RkUmU:sUm b¤RkUsuIjGUevI. exchange of chromosomal material, or crossing over. chiral center : An atom with four different substituents. mCÄmNÐlKIra:l; ³ GatUmEdlmanCMnYsbYnxusKña. chirality : An object is chiral if it cannot be superimposed on its PaBKIra:l; ³ vtßúmYyCaKIra:l;luHRtaEtvaminGacRtÜtelIKña)antamrUbPaB mirror image. This word is derived from the Greek word for “hand” rbs;vakñúgkBa©k;. BaküenHkøaymkBIBaküRkicKW {éd}eRBaHédmanlkçN³ because hands are chiral. KIra:l;. chi-square (χ2) analysis : Statistical test to determine if an karviPaKXI-kaer ³ etsþsþaTIsÞIc edIm,IkMnt;faTinñn½ysegátsmRsb observed set of data fits a eTAnwgkarrmBwgTuktamRTwsþIb¤eT. theoretical expectation. chitin : A hard carbohydrate material found in the exoskeletons KITIn ³ kabUGIuRdatrwgéneRKagq¥wgxageRkArbs;GakRtUb:Ut nigPñas of arthropods and also in the cell walls of some fungi. It is similar to eRKagrbs;pSitmYycMnYn. vamansNæanRbhak;RbEhlnwgEsluyLÚs cellulose but has an amide in place EtmanRkúmGamItCMnYs -OH enAelIkabUnelxBIrénKøúykUs. of an –OH on carbon number 2 of the glucose residues. chlorenchyma : Parenchyma tissue containing chloroplasts in kør:g;sIum ³ Calika)a:r:g;sIumEdlpÞúkkør:U)aøsénrukçCatifñak;x

chloroplast : A plastid containing chlorophyll. kør:U)aøs ³ )aøsÞItEdlpÞúkkør:UPIl. choana : Internal nostrils (plural, choanae). rn§RcmuH ³ rn§RcmuHxagkñúgEdlbgáeLIgedayq¥wgx©I. cholesterol : Most abundant steroid in animals. An important kUelesþr:ul ³ esþr:UGIutEdlsMbUrbMputcMeBaHstV. CaPñaslIBItd¾sMxan; membrane lipid with significant health implications. Excess Edlman\T§iBlsMxan;elIsuxPaB. brimaNkUelesþr:ulelIskñúgQam cholesterol in the blood can cause GacbNaþaleGaymanCMgWebHdUg. heart attack. chondrification : Formation of cartilage. kMNq¥wgx ©I ³karkekItq¥wgx©I. chordate : Any organism with a notochord, dorsal nerve cord and kred ³ Pavrs;EdlmanBYrq¥wgxñg BYrRbsaTq¥wgxñg nigrgVHRskI. gill slits. See p. 315. emIlTMBr½ 315 . chorion : The outer membrane that surrounds the embryo of the kUrü:úg ³ PñasxageRkAénfg;TwkePøaHCMuvijGMRb‘Íyu:génstVmanTwkePøaH amniotes; in mammals it helps form the placenta; a thin membrane cMeBaHfnikstVPñasenHbegáIt)anCasuk. inside the shell of an egg that has PñasesIþgCab;xagkñúgsMbks‘ut. been laid. chorionic biopsy : See chorionic chorionic villus sampling villus sampling. karBinitükUrIy:ug ³ emIl . chorionic villus sampling (CVS) : A technique of diagnosis before karykRCaMgkUr:üúg ³ Cabec©keTsvinic©½yeraKmuneBlekIt EdlGac birth that can detect cytogenetic and biochemical defects in the rkeXIjvibtþiGMRb‘Íy:ugEdlbNþalmkBIesenTicekasika nigKImICIv³ eday embryo by taking samples of fetal ykKMrUekasikaKP’BIRCaMgkUrüúgmkBinitü. cells from the chorionic villus. choroid : A layer behind the retina of the vertebrate eye which kUr:UGIut ³ RsTab;EdlenAxageRkayerTInénEPñkstVq¥wgkg Edl contains blood vessels and pigment. pÞúksrésQam nigCatiBN’. : A single strand of the chromosome pair formed by RkÚm:aTIt ³ édmçagrbs;RkUm:UsUm ekIteLIgedaykarEbkCaBIrénRkUm:UsUm splitting of a chromosome during mitosis. enAeBlmItUs. chromatin : A compound of nucleic acids and proteins that RkÚm:aTIn ³ smasFatuGasIutnuyekøGiucnigRbUetGiunEdlbgáCaRkUm:UsUm. makes up chromosomes. chromatin fibers : See nucleoproteins nucleoproteins . srésRkÚm:aTIn ³ emIl . chromatography : Technique for the separation of a mixture of viFIEjkl,ay ¬RkUma:tURkabPI¦ ³ molecules dissolved in a liquid or gas phase, by differences in their bec©keTssMrab;Ejkl,aym:UelKul EdlrlaykñúgvtßúFaturav b¤l,ay movement over a stationary ]sµ½nedayPaBxusKñaénclnaelIs‘ub®sþaEdlenAnwg. karEjkl,ay substrate. Separation of the mixture occurs because of differences in ekIteLIgedaysarPaBxusKñaénlT§PaBrlaynig /b¤karRsUbénm:UelKul solubility and/or adsorption of the molecules for the two different sMrab;vKÁBIrxusKña. s‘ubRsþaGacCasarFatuxab;Gn§il b¤sarFaturwg. va phases. The substrate can be a Gel or a solid. It can be packed into a Gacdak;eTAkñúgbMBg;ragsuILaMg b¤BRgayeTAkñúgRsTab;esþIg)an. cylindrical column or spread into a thin layer. chromatophore : A cell or a group of cells with pigment in the RkUm:atUpr ³ ekasika rWRkúmekasikamanCatiBN’enAkñúgsuItU)øasEdlstV cytoplasm which can be used to change the color of the animal. eRbIR)as;sMrab;bþÚrBN’rbs;va.

chromocenter : An collection of centromeres and heterochromatic RkUmU:sg;ET ³ bNMþúsg;RtUEm nigFatueGetrU:RkUma:TicénRkUmU:sUmbU:lIEtn. elements of polytene chromosomes. chromomere : One of the many dark stained bands on the salivary RkUmU:Em ³ bnÞHmYyénbnÞHbnSúIBN’exµACaeRcInsßitenAelIRkUmU:sUmRkeBj gland chromosomes of some insects. Each band is thought to Twkmat;énstVl¥itxøH. bnÞHnimYy²tageGayRkumEsnnImYy²epSgKña. represent a different gene group. chromoplast : A plastid containing red, orange or yellow pigments. RkÚm:U)aøs ³ )aøsÞItEdlpÞúkCatiBN’Rkhm BN’TwkRkUc nigBN’elOg. chromosomal mutation : A change in the gene arrangement in muytasüúgRkÚm:UsUm ³ karpøas;bþÚrénkartMerobEsnenAkñúgekasika Edl a cell as a result of breaks in the ADN DNA molecule. Can affect whole énkarkarEbkkñúgm:UelKul . Gacman\T§iBleTAelIRkUmU:sUmTaMgmUl chromosomes (see polyploidy , ¬sUmemIl polyploidy,aneuploidy) b¤Tak;TgeTAnwgkarpøas;bþÚrTMrg;enA aneuploidy ), or involve structural changes within chromosomes (see kñúgRkUmU:sUm ¬ sUmemIl inversion , duplication , translocation ¦. inversion, duplication, translocation ). Also compare sUmeRbobeFobpgEdrCamYy point mutation . point mutation. chromosomal polymorphism : Alternate structures or arrange- BhusNæanénRkUmU:sUm ³ TMrg;qøas;Kñab¤kartMerobRkUmU:sUmEdlpÞúk ments of a chromosome that are carried by members of a edaysmaCikénb:UBuyLasüúg. population. chromosomal rearrangement : Mutations in which chromosomal kartMerobRkÚm:UsUmeLIgvij ³ muytasüúgEdlEpñkrbs;RkUm:UsUmElg pieces are no longer present in their original location. sßitenAkEnøgedImrbs;vaeTotehIy. chromosome : In , a ADN DNA molecule complexed with RkUmU:sUm ³ cMeBaHGWkarIyU:t vaCamU:elKul rYmCamYyRbUetGuInGuIsþÚn histone proteins to form a threadlike structure containing edIm,IbegáItCaTMrg;qµar²dUcsrésrGMe)aH pÞúkBt’manesenTic tMerobCa genetic information arranged in a lMdab;ExS. cMeBaHRbUkarIyU:t vaCamU:elKul ADN Kµansg;RtUEm EdleRcIn linear sequence. In prokaryotes, a DNA molecule without EtmanragCargVg;mUl nigpÞúkesNUm. centromere, often circular and containing the genome. chromosome banding : Technique for staining mitotic or meiotic bnÞHRkÚmU:sUm ³ bec©keTsbnSúIBN’RkUmU:sUm kñúgmItUs b¤emyU:sepSg² chromosomes differently to produce a characteristic banding BIKña edIm,IbegáItCaKMrUlkçN³bnÞ³ b¤bnSúIBN’CMerIs edIm,IeGayemIleXIj pattern or selective staining of tMbn;RkUmU:sUmc,as;las; dUcCasg;RtUEm/ tMbn;erobcM begáItnuyekøGUl nig certain chromosomal regions such as centromeres, the nucleolus tMbn;sMbUr CC-b¤ AT-. kareFVIEbbenH KWedIm,IkMueGayRcLMCamYyKMrUbnÞH organizer regions, and CC- or AT-rich regions. Not to be EdlmanenAkúñgRkumRkUmU:sUmbU:lIEtnminmankarbnSúIBN’EdlRtUv)anplit confused with the banding pattern present in unstained polytene edaykartMerobRkUmU:Em. chromosomes, which is produced by the alignment of chromomeres. chromosome mapping : A method of determining the relative position karkMNt;TItaMgRkÚmU:sUm ³ viFIkMnt;TItaMgrbs;EsnenAelIRkUm:UsUm of genes on a chromosome using information on crossing-over edayeRbIBt’maneRbkg;bNþÚrExVg . frequency.

chromosome puff : A localized uncoiling and swelling in a ek¥gRkUmU:sUm ³ kEnøgrlanigeLIge)a:gkñúgRkUmU:sUmb:UlIEtn CaFmµtaRtUv polytene chromosome, usually regarded as a sign of active )aneKcat;TukfaCasBaØabBa¢ak;BIkarcMlgRkmy:agskmµ. transcription. chromosome theory : The idea that genes are located on the RTwsþIRkÚm:UsUm ³ KMnitEdlfaEsnsßitenAelIRkUm:UsUm. chromosomes. chymase : See rennin. sIum:as ³ emIl rennin . chyme : Partially digested leaving stomach. sIum ³ cMNIGaharRtÚv)anrMlayEdlcakecjBIRkBH. cilia (singular, cilium) : Tiny projections like hairs; used for eramj½r ³ eramqµar²sMrab;eFIVclnabMlas;TIénRb:UTIsþmUycMnYn movement in some , containing a highly organized array EdlbgáeLIgedaykUnbMBg;CaeRcInxøICagpøaEsl. of microtubules; shorter than a flagellum. ciliary body : The thick edge of the choroid in the vertebrate eye. It rgVg;sac;dMueRkayRbRsI ³ EKmRkas;énkUr:UGIutEPñkstVq¥wgkgEdlsßit surrounds the lens and iris and contains the ciliary muscle and enACMuvijEkvEPñknigRbRsIEPñk bgáeLIgedaysac;dMumaneramnigbeBa©j secretes the aqueous humour. TwkkBa©k;EPñk. ciliary muscle : In the vertebrate eye, the muscle that surrounds the sac;dMuEkvEPñk ³ cMeBaHEPñkstVq¥wgkg Casac;duMB½T§CuMvijEkvEPñk nig lens and is responsible for changing its shape. mantYnaTIpøas;bþÚrragrbs;EkvEPñk. circadian rhythm : Cyclic behavior patterns that are repeated cgVak;skmµPaBRbcaMéf¶ ³ KMrU\riyavdþEdlRbRBwtþeTAerogral;24em:ag. every 24 hours. circulation : The movement of blood through the body’s blood rbt;Qam ³ clnaQamkñúgsrésQaménsarBagÁkay. vessels. cirrhosis of the liver : When scar tissue gradually replaces healthy sIur:UseføIm ³ CMgWEdlsMKal;edaykarpøas;bþÚrekasikaeføImedayekasika liver cells. sMlakCabnþbnÞab;. cirrus (pl. cirri) : Among ciliated protozoans, a group of cilia that eramExñg ³ cMeBaHRbUtUsUEG‘maneramj½r CaerammYyRkummanmuxgarCa function as a single unit; among Cirripedia barnacles, the thoracic appendages, FatuekasikamYy. cMeBaHRKusþaes CaExñgRTUgEkERbsMrab; which are modified for food RbmUlykGahar. cMeBaHRKINUGIut CaExñgsÞabenACMuvijmat;eRbIR)as; collection; among crinoids, the prehensile appendages located sMrab;edIr nigsMrab;etagelIs‘ubRtarwg. aborally that are used for walking and for clinging to solid substrates. cis- : Prefix used to designate two similar groups on the same side of sIus ³ buBVbTEdleRbIsMrab;kMnt;RkúmBIrRbhak;RbEhlKñaenAelI a molecule. RCúgdUcKñaénm:UelKulmYy. cis configuration : The arrangement of two mutant sites rUbsNæansIus ³ kartMerobTItaMgmuytg;BIrkñúgEsnmYyelIGUmU:LÚkdUc within a gene on the same trans homologue. Contrasts with a trans Kña. pÞúyBIkartMerob EdlGaELlmuytg;sßitenAelIGUmU:LÚkpÞúyKña. arrangement, where the mutant alleles are located on opposite homologues.

cis dominance : The ability of a gene to affect the expression of lkçN³lubsIus ³ lT§PaBrbs;EsnEdlC³\T§iBldl;karsMEdgecj other genes adjacent to it on the chromosome. rbs;EsnCitvaepSgeTotelIRkUmU:sUm. cisterna : (plural Cisternae ) The flattened tubes and saclike regions sIusEsÞn ³ bMBg;sMEb:tnigkEnøgdUcfg;énerTIKuyLÚmGg;dU)aøs nig of the endoplasmic reticulum and of dictysomes. DictüÚsUm. cis-trans test : A genetic test to determine whether two mutations etsþsIus-Rtg;s_ ³ etsþesenTicedIm,IkMnt;faetImuytasüúgBIrsßitenA are located within the same cistron. kñúgsuIs®sþúgdUcKñarWeT. cistron : That part of a DNA ADN molecule that codes for a single suIs®sþúg ³ EpñkénmU:elKul EdlcMlgRkm sMrab;Rcvak;bU:lIbuibTIt polypeptide chain; defined by a genetic test as a region within mYyExSnigEdlRtUv)ankMnt;edayetsþesenTic faCatMbn;EdlkñúgenaH which two mutations cannot muytasüúgBIrminGacbMeBjKña)an. complement each other. citrate (citric acid) : A six-carbon organic acid that is converted to sIuRtat ¬GasuItsuIRTic ¦³ GasuItsrIragÁmankabUn 6Edl®tUv)anpøas;bþÚr isocitric acid in the second step of the Krebs cycle. eTACaGasIutGIusUsIuRTicenAkúñgdMNak;kalTIBIrénvdþERkb. citric acid cycle : A series of reactions in the aerobic phase of vdþGasIutsIuRTic ³ es‘rIRbtikmµenAkñúgvKÁmanxül;éndegðImekasikaEdl cellular respiration that breaks A down acetyl CoA to form carbon bMEbkGaesTIlkUGg;sIum eGayeTACa]sµ½nkabUnic nigTwk nigbeB©aj dioxide, water and releases energy. famBl. emIl Krebs cycle . See Krebs cycle. clade : Phylogenetic lineage originating from a common køat ³ BUCGMbUrEdlmanRbPBedImecjBIbuBVrYméncMENkfñak; nigrYmman ancestral taxon and including all grade descendants. See also grade . snþaneRkayTaMgGs;. emIl . cladistic : Refers to the branching sequences of phylogenesis. køaDIsÞic ³ sMedAeTAelIdMeNIrbnþKñaénEmkFagkñúgkMNkMeNItBUC GMbUr. cladistics : A method of classifying based on an analysis of køaDIsÞic ³ viFIcMENkfñak;tamkarviPaKedayELkrYmKñaEdlbgðajBI shared features that shows ancestral relationships among TMnak;TMngbuBVkñúgcMeNamPavrs;. organisms cladogram : A line diagram of a branching pattern of evolution, køadURkam ³ düaRkamCaEmkFagénkarvivtþn_ edayeRbIbBaØtþnig using the concepts and methods of cladistics. viFIénkøaDIsÞic. cladophyll : A stem or branch that resembles a leaf køadUhVIl ³ Emk b¤edImEdldUcKñaeTAnwgsøwk. clamp connection : A loop-like lateral connection between CMnab;rgVg; ³ CMnab;tamcMehogragCargVg; rvagekasikaenACitKña Edl adjacent cells, occurring in the mycelium of certain basidiomycete ekIteLIgenAkúñgmIeslüÚmrbs;pSit)asuIdüÚmIEst. fungi. class : A group of related orders in (classification). A fñak; ³ RkuménlMdab;EdlmanTMnak;TMngKñakñúgrebobcMEnkfñak;. taxonomic category ranking between division and order. See p. cMNat;fñak;;énrebobcMENkfñak;sßitenAcenøaHsaxaniglMdab;. emIlTMBr½ 311. 311 .

classical conditioning : A form of learning in which an organism l½kçx½NÐTMlab; ³ TMrg;énkarsikSaEdlPavrs;pSMrMejacnigtMNb Edl associates a previously unrelated stimulus and response. minTak;TgKñaBImunmk. classification : To put organisms that are similar into groups called cMEnkfñak; ³kardak;Pavrs;EdlmanlkçN³ Rbhak;RbEhlKñaeTACa taxa. eg Kingdom, phylum, division, class, order, family, Rkum² ehAfaÉktacMENkfñak;. ]TahrN_ ³ rC¢³- saxa- fñak;- lMdab;- genus, species. Classification is GMbUr- BYk- RbePT. CacMENkfñak;eRcInEtEp¥kelI TMnak;TMngvivtþn_. usually based on evolutionary (phylogenetic) relationships. See emIl cladistics . emIlTMBr½ 311 . Cladistics. See p. 311 cleavage : One of the first cell divisions in a zygote. cMENkekasikadMbUg ³ cMEnkekasikamYykñugcMenamcMEnkekasikadMbUg énsIukUt. cleavage furrow : A fold of the cell membrane at the beginning of cg¥ÚrEckekasika ³ pñt;rbs;PñasekasikaenAeBlcab;epþImeFIVcMEnk cytokinesis in animal cells. sIutU)aøsénekasikastV. cleidoic egg : An egg that is independent of the environment s‘utekødUGiuc ³ s‘utmincMNuHbrisßan elIkElgkarbþÚrkMedA nig]sµ½n except for heat and gas exchange (carbon dioxide, oxygen, water ¬]sµ½nkabUnic GuksuIEsn cMhayTwk¦. lkçN³sMKal;rbs;stVmanTwk- vapor). Characteristic of amniotes. ePøaH. cleistothecium : A closed, more or less spherical ascocarp. ekøsþÚefsüÚm ³ GasáÚkabbiTCit EdlmanragmUlticb¤xøaMg. climacteric rise : Point during the ripening of some fruit in which kMenInx

closed circulatory system : A circulatory system in which blood RbB½n§rbt;QambiT ³ RbB½n§rbt;QamEdlQamsßitenAEtkñúgsrés is enclosed in vessels throughout the body. QamBaseBjsarBagÁkay. clutch : A group of bird’s eggs laid at one time. s‘utrYmCMnan; ³ s‘utbkSI;EdlemBgmYyelIk².

CO 2 compensation point : CO 2 ³ kMhab; CO 2EdlkarRsUbcUlesµInwgkarbeBa©j. Concentration of CO 2 at which the cMNucesµI uptake of CO 2 equals the release of CacMNucEdlrsµIsMeyaKesµInwgdegðIm. CO 2; that is, the point at which photosynthesis equals respiration. coacervate : A collection of organic macromolecules kUGaEs‘v:a ³ bNþúMm:UelKulsrIragÁFM²EdlB½n§CMuvijedaym:UelKulTwk surrounded by water molecules, aligned to form a sphere. tMerobKñaedIm,IbegáItCaEs‘VmYy. coated pit : A bristle-like structure that occurs in clusters in certain kMhUgPñas ³ TMrg;ragdUceramrwg² EdlekIteLIgpþúMKñaenAkEnøgxøHénPñas regions of the plasma membrane; these regions form vesicles that )aøsµa. tMbn;TaMgenHbegáIt)anCafg;Edldac;cUleTAkñúgekasika edIm,ICMruH pinch off into the cell, thereby ecalnUvPñas)aøsµaEdlelIstMrUvkar. removing excess plasma membrane. cocci : Eubacteria with spherical shapes. )ak;etrIragEsV‘ ³ )ak;etrIBitEdlmanragEs‘V. cochlea : A fluid filled coiled tube in the middle ear receiving bMBg;ragKUTxüg ³ vtßúravkñúgbMBg;ragKUTxügenAkñúgRtecokkNþal vibrations that stimulate the auditory nerve. manmuxgarTTYlrMj½rEdlePJacsrésRbsaTesatviBaØaN. code : See . Rkm ³ emIl genetic code . codominance : A condition that occurs when both alleles of a lubmineBjelj ³ l½kçx½NÐEdlekItmanenAeBlGaELlTaMg heterozygous gene are expressed equally. BIrénEsneGetr:UsuIkUt®tUv)ansMEdgecjesµIKña. codon : A sequence of three ARNm nucleotides in a gene or molecule kUdug ³ lMdab;nuyekøGUTItbIkñúgEsnmYy b¤m:UelKul EdlRtUvKña of mRNA that corresponds to a specific amino acid or to a stop eTAnwgGasIutGamIenyfaRbePTmYy rWsBaØabBa©b;énsnmYy. mankUdug signal at the end of a gene; there cMnYn 64kñúgenaHman 61cMlgRkmsMrab;GasuItGamIen nigbIeTotCakUdug are 64 possible codons, 61 are codes for amino acids and three are sþúb. stop codons. coefficient of coincidence : A ratio of the observed number of emKuNCYnKña ³ smamaRténcMnYnsegátRkUsuIjGUevIBIrdgEckeGaycMnYn double-crossovers divided by the expected number of such rMBwgénRkUsuIjGUevIenH. crossovers. coefficient of selection : See selection coefficient selection coefficient. emKuNCMerIs ³ emIl . coelogastrula : The typical gastrula derived from a sWLÚhÁaRsÞÚLa ³ hÁaRsÞúLatYy:agmanRbPBecjBIsWLÚhÁaRsÞÚLa. coeloblastula; a two or three— layered stage in . dMNak;GMRb‘Íyu:gEdlmanBIrb¤bIRsTab;. coelom : A body cavity filled with fluid surrounded by mesoderm. sWLÚm ³ RbehagsarBagÁkaymansarFaturav nigB½T§CMuvijeday emsUEDm.

coenocyte : An organism, or part of an organism, that is sWNUsIut ³ Pavrs; b¤CaEpñkrbs;Pavrs;BhuéNVy:U Edlmin®tUv)anEck multinucleate, the nuclei not being separated by membranes or cross- edayPñasb¤PñaseRKageT. walls. coenzyme : A nonprotein molecule that works with an enzyme to kUGg;sIum ³ m:UelKulminEmnRbUetGIun EdlrYmCamYyGg;sIumedIm,ICMuruj catalyze a reaction. el,ÓnRbtikmµ. coenzyme Q see Ubiquinone kUGg;sIum Q ³ emIl Ubiquinone . coevolution : Complex biological interaction and adaptation resulting shvivtþn_ ³ GnþrGMeBI nigbnSMaCIv³pSMKñaEdleFVIeGaymanlkçN³rYm in unique features in both inter- acting species. eg. insects and the mYy kñúgRbePTGnþrGMeBITaMgBIr. ]TahrN_ ³ stVl¥itnigpáa ¬EdlGnþrGMeBI flowers they pollinate. kñúgdMeNIrlMGg ¦. cofactor : A non-protein substance required by enzymes for proper kUhVak;T½r ³ sarFatuminEmnRbUetGuIn Edl®tUvkaredayGg;suImsMrab; function. dMeNIrkareGay)anl¥. cohesion : The attraction between like molecules. kMlaMgTMnaj ³ TMnajrvagm:UelKulnigm:UelKul. cohesive end : Sections of DNA DNA single-stranded DNA at the ends of cugP¢ab; ³ Epñkén Rcvak;eTal sßitenAxagcug Rcvak;eTV double-stranded DNA that can stick the two ends of the molecule EdlGacP¢ab;cugm:UelKulTaMgBIrCamYyKñaedaykarbMeBjKU)asKña. together by complementary base pairing. coitus : See sexual intercourse . emIl sexual intercourse . colchicine : An alkaloid compound that inhibits spindle formation and kulsuIsuIn ³ smasPaBGal;kaLÚGIut Edlbg¥ak;karbegáItRtyUgGa- induces polyploidy in plants during cell division. Used in the RkUma:Tic nigeFVIeGaymanb:UlIbøÚGIutcMeBaHrukçCatikñúgeBlcMENkekasika. preparation of karyotypes to collect vaRtUv)aneRbIR)as;kñúgkarerobcMkarIyU:TIbedIm,IRbmUlb:UBuyLasüúgekasika a large population of cells inhibited at the metaphase stage of mitosis. d¾¾FM EdlRtUv)anbg¥ak;enAvKÁemtapasénmItUs. cold-blooded : Having a body temperature that changes with the GefrkMedA ³ EdlmansItuNðPaBsarBagÁkayERbRbYleTAtam temperature of the surroundings. sItuNðPaBbriyakas. coleoptile : The first leaf of a monocot that forms a protective eRsamsøwkBnøk ³ søwkTImYyrbs;m:UNUkUTIeldUnEdlCaRsTab;karBar sheath around the growing shoot. CuMvijBnøkRtYy. coleorhiza : The protective sheath around the embryonic root in grass eRsamrwsBn¶k ³ eRsamkarBarenACMuvijrwsGMRb‘Íy:ugkñúgRKab;RkamIen. seeds colicin : A bacteriocidal protein E coli produced by certain strains of E. kUlIsIun ³ RbUetGuInRbqaMg)ak;etrI pliteday)ak;etrI > xøH nig coli and other closely related E.coli bacterial species. RbePT)ak;etrIepSgeTotEdlmanRsLayCamYy . colinearity : The linear relationship between the nucleotide TMnak;TMngExSrYm ³ TMnak;TMngCaExSrvagtMnlMdab;nuyekøGUTItkñúgEsn sequence in a gene (or the RNA ARN transcribed from it) and the order ¬b¤ EdlcMlgRkmecjBIva ¦ niglMdab;GasuItGamIenkñúgRcvak; of amino acids in the polypeptide b:UlIbuibTItkMNt;edayEsnenaH. chain specified by the gene. collagen : A fibrous protein that is found in connective tissue. kULaEsn ³ srésRbUetGIunenAkñúgekasikasn§an.

collar cell : Flagellated cell lining the internal cavities of a sponge. ekasikacgáMk ³ ekasikamanpøaEslEdltMerobenAépÞRbehagxagkñúg rbs;eGb:ug. collecting duct : A small tube that drains urine from the nephron into bMBg;TTYlTwkenam ³ bMBg;dwknaMTwkenamBIenRhVúgeTAkEnøgRbmUlpþMú the renal pelvis. Twkenam. collenchyma : A plant tissue specialised for strength and kULg;sIum ³ CalikarukçCatiEdlmannaTIBRgwgnigRTRTg;. support. colligative properties : Properties of solutions that are affected only lkçN³xUlIehÁFIv ³ lkçN³rbs;sUluysüúgEdlmanTak;TgEtnwg by the concentration of the solute, not by its chemical identity. kMhab;Faturlayb:ueNÑaHminTak;TgnwgGtþsBaØaNkmµKImIrbs;vaeT. colloid : Mixture in which the solute is evenly distributed but kULÚGIut ³ l,ayEdlkñúgenaHGgÁFaturlayRtÚv)anBRgaysBV b:uEn þ present in particles of sufficient size to reflect or scatter light. CaPaKl¥itEdlmanTMhMsmlµmnwgbMpøatrWbMEbkBnøW. colon : Large intestine. See p. 322 eBaHevonFM ³ emIlTMBr½ 322 . colonial : A term used to describe a collection of cells that cooperate kULÚnI ³ BaküeRbIedIm,Ierobrab;BIkarenApþúMKañrbs;ekasikaEdlshkarKña to a small extent. CaRTg;RTaytUc. colony : A cluster of genetically identical individuals formed kULÚnI ³ RkumÉktþ³EdlmanlkçN³esenTicdUcKña kekIteLIgBIkar asexually from a single colonizing individual. bnþBUCeday\tePTénÉktþ³mYykñúgkULÚnI . colony hybridization : A (probes) technique that uses probes to find GIuRb‘ÍtkmµkULÚnI ³ bec©keTsEdleRbIRb:Ub edIm,IEsVgrkkULÚnI bacterial colonies that contain a gene of interest. )ak;etrI EdlmanpÞúknUvEsnEdleKcg;)an rWEsnEdlmanRbeyaCn_. colour blindness : Inability to see any difference between some or all ggwtBN’ ³ KµanlT§PaBemIleXIjPaBxusKñarvagBN’mYycMnYn rWRKb; colours. The most common is red- green colour blindness which is BN’TaMgGs;. ggwtBN’CaTUeTAbMputenaH KWRkhm-ébtg EdlRtYtBinitü controlled by a recessive gene on edayEsnGn;enAelIRkUmU:sUm X. the X chromosome. columella : 1. Cells in the center of the root cap; 2. column of sterile kUluyEml ³ 111-1 ekasikaenAEpñkkNþalénk,alrws . 222-2 ssrén cells in the center of the capsule in mosses; 3. pillar supporting the ekasikaminbnþBUCsßitenAkNþalkenSaménEsø. 333-ssrRTRTg;s,:r:gsIum3 sporangium in some fungi; 4. énpSitmYycMnYn. 444-4 GkS½ rW sñÚlkNþalrbs;EpøeQI. central axis of a fruit. combined gas law : Combination of Charles’ law (compensating for c,ab;pSM]s½µn ³ bnSM;rvagc,ab;sal ¬bMErbMrYl sItuNðPaB ¦ nigc,ab; temperature change) and Boyle’s PV Boyle = constant law (compensating for pressure ¬bMErbMrYlsMBaF ¦. T . change). commensalism : A symbiotic relationship in which one organism GDÆshR)aN ³ TMnak;TMngshR)aN EdlPavrs;mYyTTYlpl nig benefits and the other is unaffected. Pavrs;mYyeTotminxatpl. community : All the populations of organisms living in a specific shKmn_ ³ b:UBuyLasüúgTaMgGs;énPavrs;;Edlrs;enAkñúgtMbn;NamYy. area.

companion cell : A type of parenchyma cell found in ekasikatam ³ RbePTénekasika)a:r:g;sIum EdlP¢ab;CamYyFatubMBg; association with sieve-tube elements in phloem tissue. They RbehagenAkñúgCalikapøÚEGm. ekasikaTaMgenHRbEhlGactMrUvbMlas;TI probably regulate translocation of FatukñúgFatubMBg;Rbehag. materials in sieve-tube elements. competence : In bacteria, the transient state or condition during kMeb:tg; ³ cMeBaH)ak;etrI CasPaB rWl½kçx½NÐkñúgkMLúgeBlxøI which the cell can bind and ADN internalize exogenous DNA EdlekasikaGacP¢ab;nigbBa©ÚleTAEpñkxagkñúgnUvmU:elKul BIeRkA molecules, making transformation EdleFVIeGaymanbMElgekIteLIg. possible. competition : The interaction between individuals that use one or karRbkYtRbECg ³ GnþrGMeBIrvagÉktþ³EdleRbIFnFanmYyb¤eRcIndUcKña. more of the same resources. competitive exclusion principle : One of two competing species will eKalkarN_QñH ³ RbePTmYyénRbePTRbkYtRbECgKñaBIr Edl be better able to control the use of the common resource thus nwgRKb;RKgFnFanrYm dUecñHeFVIeGayRbePTmYyeTotRtUv)at;bg;. eliminating the other species. competitive inhibition : The formation of a temporary karbg¥ak;RbECg ³ karbegáItCabeNþaHGasnñ nUvkuMepøcGg;sIum-Gñkbg¥ak; enzyme-inhibitor complex that interferes with the normal Edlbg¥ak;karbegáItkuMepøcGg;sIum-s‘ubRsþa eFIVeGaydMeNIrkarrbs; formation of enzyme-substrate Gg;sIumfycuH. complexes, resulting in a decreased turnover. competitive inhibitor : Reversible inhibitor that binds to the active GñkraMgxÞb;RbECg ³ GñkraMgxÞb;EdlP¢ab;eTAnwgkEnøgskmµénGg;sIum nig site of an enzyme and thus competes with the substrate. bnÞab;mkRbECgCamYys‘ubRsþa. complementarity : See complementary base complementary base. eKalkarN_bMeBjKñaén)as ³ emIl . complementary base : A base that can form hydrogen bonds with )asbMeBj ³ )asEdlGacP¢ab;sm<½n§GIuRdUEsnCamYy)asmYyeTot another base of a specific nucleotide. e.g. guanine pairs with énnuyekøGUTItyfaRbePTmYy. ]TahrN_³háanInKUCamYysIutUsIun cytosine and adenine pairs with nigGaednInKUCamYyTImIn ¬ rWGu‘yra:sIulkñúg ARN ¦. thymine (or uracil in RNA). complementary DNA (cDNA) : ADN ADN DNA that is made by reverse bMeBj ³ EdlRtUv)anbegáIteLIgedaykarbkERbRtlb; transcribing mRNA into its DNA ARNm ADN ADN complement; the collection of eGayeTACa bMeBjrbs;va. karRbmUlpþMúGgát; køÚnvicT½r vector cloned cDNA fragments of rbs;Pavrs;mYyCasmUh ADN bMeBjrbs;va. an organism are its cDNA library. complementation test : A genetic test to determine whether two etsþbMeBjKña ³ etsþesenTic edIm,IkMnt;faetImuytasüúgBIrekIteLIg mutations occur within the same gene. If two mutations are kñúgEsndUcKñab¤eT. ebIsinCamuytasüúgBIrRtUbv)anbBa©ÚleTAkñúgekasika introduced into a cell at the same enAeBlEtmYy nigmankarplitepNUTIbéRB ¬KWfavabMeBjKñaeTAvijeTA time, and produce a wild-type phenotype (i.e., they complement mk ¦ vaeRcInEtminEmnCaGaELlnwgKñaeT. ebIsinCaepNUTIbmuytg; each other), they are often not alleles. If a mutant phenotype is RtUv)anplit enaHmuytasüúgKµankarbMeBjKñaeT ehIyeRcInEtCaGaELl produced, the mutations do not complement each other and are nwgKña. often alleles.

complete dominance : A condition that occurs when the lubeBjelj ³ l½kçx½NÐEdlekIteLIgenAeBlEdlepNUTIbrbs; phenotype of one allele completely masks the phenotype of another GaElsmYylubTaMgRsugeTAelIepNUTIbrbs;GaElsmYyeTotsMrab; allele for a heterozygous gene. EsneGetr:UsuIkUt. complete flower : A flower that has sepals, petals, stamens and a páaeBjelj ³ páaEdlmanRtbk RsTab; kBa©MúeksreQµal nigkBa©úM pistil. eksrjI. complete linkage : A condition in which two genes are located so CMnab;Cit ³ l½kçx½NÐEdlEsnBIrmanTItaMgsßitenACitKñaeBkrhUtdl; close to each other that no recombination occurs between eFVIeGayKµanbnSMeLIgvijekIteLIgenAcenøaHEsnTaMgBIrenaH. them. complete protein : Protein molecules that provide all the RbÚetGIuneBjelj ³ m:UelKulRbUetGIunEdlpþl;RKb;GasIutGamIen essential amino acids. sMxan;TaMgGs;. complex carbohydrates : Macromolecules composed of kabUGIuRdatkMuepøc ³ m:aRkUm:UelKulbgáeLIgedaymU:elKulsárgay simple sugars (fructose, glucose) fructose, glucose that have joined together by ¬ ¦EdlP¢ab;Kñaedaymankarpþac;mU:elKulTwWkecj releasing molecules of water; or b¤b:UlIsakarItEdlGacrMlay)anénGahar PaKeRcInKWGamIdug. digestible polysaccharides of the diet, mostly starches. complex locus : A gene within which a set of functionally related LÚKuskMuepøc ³ EsnEdlRkumGaELlEdlmanTMnak;TMngKñaEpñkmuxgar pseudoalleles can be identified by bithorax recombinational analysis (e.g., the GacsMKal;)anedayviPaKbnSMeLIgvij ¬]TahrN¾ LÚKus bithorax locus in Drosophila ). énRdUsUPIl ¦. complexity : In genetics, the total number of nucleotides or PaBsaMBaJaMú ³ kñúgesenTic CacMnYnsrubénnuyekøGUTIt b¤KUnuyekøGUTIt nucleotide pairs in a population of reassociation nucleic acid molecules as kñúgb:UBuyLasüúgénmU:elKulGasuItnuyekøGuicEdlkMnt;eday determined by reassociation kinetic . emIl reassociation kinetics . kinetics. See reassociation kinetics . compost : Partially decayed organic matter used in farming and kMub:us ³ sarFatusrIragÁpuyrlYy EdleKeRbIkñúgkareFVIksikmµ nigkar gardening to enrich the soil and increase its water-holding capacity. eFVIsYn edIm,IbegáInCICatidI nigbegáInsmtßPaBpÞúkTwkrbs;va. compound : Pure substance containing two or more chemically smasFatu ³ sarFatusuT§EdlmanFatuBIr rWeRcInEdlP¢ab;Kñaeday bonded elements in definite and constant proportion. For example, sm<½n§KImI kñúgsmamaRtkMnt;nigefr. ]TahrN_sármankabUn42/1 sugar (sucrose) is always 42.1 PaKry GIuRdÚEsn6/4PaKry nigGuksIuEsn51/5PaKryénma:s. percent carbon, 6.4 percent hydrogen, and 51.5 percent oxygen smasPaKrbs;vaGacEjkecjBIKñaEttammeFüa)ayKImI. by mass. Its components can only be separated by chemical means. compound eye : An eye made up of many individual light-sensitive EPµñkEkveRcIn ³ EPñkEdlbgáeLIgedayÉktarYsBnWøeRcIn. units. compound formula : Formula of an ionic compound, which gives rUbmnþsmasFatu ³ rUbmnþénsmasFatuGIuy:UnicEdlpþl;nUv the identity and number of each atom in the smallest repeating unit GtþsBaØaN nigcMnYnGatUmnimYy²enAkñúgÉktaEdltUcbMputrbs; of the compound. smasFatuenaH.

compound leaf : A type of leaf in which many small leaflets are søwkrYm ³ RbePTsøwkEdlkUnsøwktUc²CaeRcInCab;KñaelITgsøwkEtmYy. attached to the same petiole. compound microscope : A magnifying device with two lenses mIRkUTsSn_smas ³ ]bkrN¾BRgIkEdlmanEkvBRgIkBIr KWGubsiucTIb – objective and eyepiece. nigEkvBRgIkEk,rEPñk. compression wood ( see reaction reaction wood wood ) : compression wood forms sac;eQIENn ¬emIl ¦ ³ sac;eQIENnenAEpñkxag along the lower side of leaning stems; compression wood expands eRkamtambeNþayedImeRTt. sac;eQIenHBRgIknigrujedImeTAelITb;Tl; and pushes the stem up against nwgTMnajEpndI. gravity. concatemer : A chain or linear series of subunits linked together. tMNCaExS ³ Rcvak; b¤es‘rIExSbnÞat;énÉktargEdlP¢ab;Kña. dMeNIr The process of forming a concatenation concatemer is called concatenation begáIttMNCaExSenHehAfa ¬]TahrN¾ BhuÉktaén (e.g., multiple units of a phage esNUmpasEdlekIteLIgenAeBlsV½ydMelIgeTV ¦. genome produced during replication). concentration : Measure of the amount of solute per unit of kMhab; ³ rgVas;brimaNGgÁFaturlaykñúgmYyxñatsUluysüúgEdlbBa¢ak; solution, expressed as mass per unit volume, mass percentage, BIma:skñúgmYyxñatmaD PaKryCama:s- PaKryCamaD rWCam:UlkñúgmYy volume percentage, or moles per lIRt. liter. concentration gradient : The gradual change in the number of CMralkMhab; ³ karERbRbYlbnþicmþg²éncMnYnmU:elKulkñúgmYyÉkta molecules per unit of volume over distance. maDeTAtamkEnøgsßitenA. ]TahrN¾ ³ TwkføaxagelImankMhab;exSay CagTwkmankkrxageRkam. conceptacles : Reproductive organs found in brown algae. kugsibtak ³ srIragÁbnþBUCrbs;sarayetñat. conception : Fertilization. karbgákMenIt concordance : Pairs or groups of individuals identical in their kugkrdg; ³ KU b¤RkumÉktþ³EdlmanepNUTIbdUcKña. kñúgkarsikSaBI phenotype. In twin studies, a condition in which both twins kUnePøaH Cal½kçx½NÐEdlkUnePøaHTaMgBIr)anbgðaj b¤min)anbgðajeGay exhibit or fail to exhibit a trait eXIjnUvlkçN³sMKal;edaykarGegát. under investigation. condensed formula : Condensed representation of a chemical rUbmnþbMRbÜj ³ kartagbMRbÜjénTMrg;FatuKImIEdlmineRbIsm<½n§Qr nig structure that leaves out the vertical CH 3CH 2CH 3 bonds and shows the whole bgðajTMrg;TaMgmUlenAkñúgCYrEtmYy dUcCa . structure set on one line, such as CH 3CH 2CH 3. conditional mutation : A mutation that expresses a wild-type muytasüúgl½kçx½NÐ ³ muytasüúgEdlsMEdgecjnUvepNUTIbéRB phenotype under certain (permissive) conditions and a eRkaml½kçx½NÐ ¬TUlay ¦mYycMnYn nigepNUTIbmuytg;eRkaml½kçx½NÐ mutant phenotype under other ¬mankMnt;; ¦déTeTot. (restrictive) conditions. conditioned response : The behavior displayed when the tMNbmanl½kçx½NÐ ³ karsMEdgGakb,kiriyaeqøIytbeTAnwgrMejacpSM neutral stimulus is given after association has occurred. bnÞab;BIkarpSMrMejacenHCamYyrMejacFmµta. ]TahrN_³ sñÚrCYgpSM CamYycMNIGahardak;eGayEqárbs;elak):avLÚv.

cone : 1. A light-sensitive cell of the retina that responds to bright 1>ekasikaekan ³ ekasikarYsBnøWrbs;erTInEdleqøIytbeTAnwgBnøW lights and colours; 2. Seed or pollen bearing structure in xøaMgnigBN’ . 2>ekan ³ RKab;rWTMrg;pÞúklMGgénrukçCatisIumNUEs

conspecific : Belonging to the same species as that under rYmRbePT ³ sßitenAkñúgRbePTdUcKña EdlkMBugBiPakSaenAeLIy. discussion . See heterospecific . emIl Heterospecific . constrictor : A snake that kills its prey by encircling and suffocating Bs;rit ³ Bs;EdlsMlab;rMBarbs;vaedayriteGayfb;degðIm. it. consumer : An organism that gets its food from another organism or GñkeRbIR)as; ³ Pavrs;EdlTTYlcMNIGaharBIPavrs;epSgeTot rW BI organic matter. sarFatusrIragÁ. continuous spectrum : Continuous band of all colors s,iúcCab;³ bnÞ³BN’TaMgGs;Cab;²Kña Edl)anbeBa©jedayGgÁFaturwg emitted by a hot solid. ekþA. continuous synthesis : The ADN 5’ uninterrupted synthesis of DNA in sMeyaKCab; ³ sMeyaK\tQb;Qrén enAkúñgTisedA eTATis the 5’ to 3’ direction; continuous 3’ synthesis occurs in the same edA . sMeyaKCab;ekIteLIgenAkúñgTisedAdUcKñaeTAnwgTisedArbs; direction as a growing replication CMBamsV½ydMeLIgeTV. fork. contour feathers : Any of the large flight feathers or long tail søabmFüm ³ søabEdlduHRKbBIelIeramsMLI eRcInEtenAelIdgxøÚnnig feathers of a bird. Kl;knÞúy. contour plowing : A method of erosion prevention in which karP¢Ürkat;TTwg ³ viFIkarBarsMNwkedaykarP¢Ürkat;TTwgdICMral. plowing is done across a slope. contractile vacuole : An organelle that maintains osmotic pressure v:aKuyGUlk®nþak; ³ FatuekasikaEdlrkSasMBaFGUsµÚs nigbeBa©jTwk expels excess water from a . EdlelIsecjBIRbUTIsþ. control group : The situation used as the basis for comparison in a RkumRtÜtBinitü b¤ RkumeKal ³ sßanPaBEdleRbICamUldæansMrab; controlled experiment. eg. If we want to identify bacteria in the soil, eRbobeFobkñúgBiesaFn_RtYtBinitü. ]TahrN_ ³ RbsinebIeyIgcg;sÁal; we can put some soil onto sterile )ak;etrIenAkñúgdI eyIgGacdak;dImYycMnYntUceTAelImCÄdæanbNþúHEdlKµan culture medium in a Petri dish. But we have another dish with the emeraKenAkñúgRbGb;eb:RTI. b:uEnþeyIgmanRbGb;eb:RTImYyepSgeTot Edl same medium without soil for comparison, so we are sure that manmCÄdæanbNþúHdUcKña EtGt;mandak;dIeT sMrab;eFVIkarRtYtBinitü dUecñH the bacteria we see are only from the soil. The dish without soil is eyIgdwgc,as;fa )ak;etrIEdleyIgeXIjmanRbPBEtmkBIdI. RbGb;eb:RTI called the control. EdlKµandIehAfaRbGb;eb:RTIRtYtBinitü. control processes : Mechanisms that ensure that an organism will dMeNIrRtÜtBinitü ³ clnkarEdlFanafa Pavrs;eFIVskmµPaB carry out all metabolic activities in the proper sequence (coordination) emtabUlIsTaMgGs;tamlMdab;RtwmRtUv nigtamGRtaRbRBwtþeTARtwmRtUv. and at the proper rate (regulation). control subject : The part of an experiment that is used as a kmµvtßúRtÜtBinitü ³ EpñkénBiesaFn_EdlRtUv)aneRbIeFIVCaKMrUeRbobeFob standard of comparison for experimental observations. sMrab;karsegátBiesaFn¾. controlled breeding : Allowing only the individuals with a selected karbgáat;RtÜtBinitü ³ edayGnuBaØateGayEtÉktþ³ EdlmanlkçN³ trait to reproduce. eRCIserIseFVIkarbnþBUC. controlled experiment : An experiment in which only one BiesaFn_RtÜtBinitü ³ BiesaFn_EdlmanEtktþaEtmYyKt;EdlRtUv)an factor is varied. eFVIeGayERbRbYl.

convergence see convergent Convergent evolution evolution kugEvsg; ³ emIl . convergent evolution : The process whereby similar vivtþn_rYmcUl ³ lMnaMEdllkçN³dUcKñaRtUv)anvivtþedayÉkraCüénRkum characteristics are independently evolved by different groups of Pavrs;xus²KñaeqøIytbeTAnwgl½kçx½NÐCMerIsdUcKña. ]TahrN_ ³ organisms in response to similar ragrbs;RtI nigdUlhVIn. selective pressures. eg. the shape of fish and dolphins. conversion factor : Fraction in which numerator and denominator emKuNbMElg ³ RbPaKEdlkñúgenaHPaKyknigPaKEbgmanÉktaxusKña are in different units, but which are equal to the same quantity. The b:uEnþmanbrimaNdUcKña. tMélBICKNitrbs;emKuNbMElgKW1. algebraic value of the conversion factor is always 1. convolution : A fold, twist, or coil of any organ especially the brain. Knøg rWpñt; ³ pñt;bt;Ebn rWrmYrénsrIragÁNamYy CaBiessxYrk,al. coordinate covalent bond : Covalent bond in which both elec- sm<½n§kUva:Lg;esµIKña ³ sm<½n§kUva:Lg;EdleTVtaeGLicRtúgRtÚv)anpþl; trons are contributed by one of the atoms. edayGatUmmYyénGatUmTaMgGs;. cori cycle : Cycle in which lactic acid produced in muscle is vdþkUrI ³ vdþEdlkñúgenaHGasIutLak;Ticplitkñúgsac;dMuRtÚv)anbMElg converted back to glucose in the liver. eTACaKøúykUsvijenAkñúgeføIm. cork : A water-resistant outer layer of cells in plant roots and Elüs ³ RsTab;ekasikaxageRkAEdlFn;nwgTwkenAkñúgrws rWedImrukçCati. stems. cork cambium : A layer of cells that produces water-resistant cork RsTab;emeRkA ³ RsTab;ekasikaEdlbegáItekasikaElüsFn;nwgTwk. cells. corm : A short, thick fleshy underground stem in some edImemIm ³ edImeRkamdIxøI nigmansac;Rkas;rbs;rukçCatim:UNUkUTIeldUn monocots. Does not have fleshy leaves. eg Gladioli . mYycMnYn. vaKµasøwksac;eT. ]TahrN_ ³ cn§Úm:ael. cornea : The transparent covering of the eye. kren ³ EpñkføaénRKab;EPñk. corolla : The petals of a flower. kBa©úMRsTab;páa coronary circulation : The supply of blood to the heart. rbt;QamkUr:UEn ³ karpÁt;pÁg;QameGayebHdUg. corpus luteum : Tissue that forms from a ruptured ovarian follicle GgÁelOg ³ CalikaEdlekItBIpUelKulGUEvbnÞab;BIGUvulxÞat;ecj nig and that produces progesterone. EdlplitGrm:UnRbUesesþr:Un. cortex : A food-storage area in plants that extends from the EpñksMbk ³³³ kEnøgsþúkGaharénrukçCatiEdllatsn§wgBIeGBIEDm epidermis to phloem. dl;pøÚEGm. corticoid hormones : Hormones secreted by the adrenal cortex that Grm:UnkrTIkUGIut ³ Grm:UnbeBa©jedayEpñksMbkénkenSamelItMrgenam help maintain water and salt balance and blood sugar level in EdlCYyrkSalMnwgTwknigGMbil nigrkSakMritsárkñúgQaménsarBagÁkay. the body. cosmid : A vector designed to ADN allow cloning of large segments of kUsµúIt ³ vuicTr½ EdlbegáItsMrab;GaceGayeFVIkøÚnGgát;pSMén BIeRkA. foreign DNA. Cosmids are hybrids composed of the cos sites of kUsúµItCaGuIRb‘ÍtEdlekIteLIgBItMbn;kUsrbs;)ak;etrIyU: -pasLam;daEdl bacteriophage lambda, inserted into s‘kbBa©ÚleTAkñúg)aøsµItrbs;)ak;etrI. a bacterial plasmid.

cosmine : Form of dentin containing branching canals kUsµIún ³ TMrg;énPøúk manbMBg;EbkEmktUc² EdlCalkçN³sMKal;én characteristic of the cosmoid scales Crossopterygian of crossopterygian fishes and early RskaPøúkénRtIq¥wg nigRtImansYtCMnan;mun. dipnoans. cotyledon : Embryonic leaf of a seed plant that provides food for kUTIeldug ³ søwkGMRb‘Íy:ugkñúgRKab;rukçCati Edlpþl;Gahardl;kUn the young plant. rukçCati. cotylosaur : A primitive group of fossil reptiles that arose from the kUTILÚs½r ³ RkumlµÚnpUsuIlCMnan;edIm Edl)anvivtþlUtlas; BIGMbUrkEgáb labyrinthodont amphibians and labyrinthodont became the ancestral stem of all CMnan;edIm nigkøayeTACabuBVénlµÚndéTeTotTaMgGs;. other reptiles. countershaded : Color pattern in which the aspect of the body that is BN’pÞúyKña ¬rvagEpñkxñg nigEpñkeBaH¦ ³ KMrUBN’énTidæPaBxøÜnEdlRtUv more brightly lighted (normally, the dorsal surface) is darker BnøWxøaMg ¬FmµtaEpñkxagxñg ¦manBN’ditxøaMgCagépÞEdlminsUvRtÚvBnøW colored than the less brightly ¬xageBaH ¦. \T§iBlénKMrUBN’enHeFVIeGayeKBi)akEbgEckstVBImCÆdæan illuminated surface. The effect of countershading is to make an Edlvars;enA. animal harder to distinguish from its back-ground. coupled cotransport system : A set of active and passive transport RbB½n§dwknaMrYmKña ³ Rkum®bUetGuIndwknaMskmµ nigGkmµEdleFVIbMlas;TI proteins that work to actively move ions across a membrane against GuIy:ugqøgkat;Pñasy:agskmµBIkEnøgEdlmankMhab;TabeTAkEnøgEdl their gradient, then passively allow mankMhabx

cranial : Related to the cranium or skull, a unique and unifying llad¾k,al ³ EdlTak;Tgnwgllad¾k,al b¤eRKagq¥wgk,alEdlCa characteristic of all vertebrates. lkçN³EtmYy nigmanÉksNæanPaBrbs;stVq¥wgkgTaMgGs;. cranial nerve : A nerve that branches from the brain. srésRbsaTxYrk,al ³ srésRbsaTEdlEbkecjBIxYrk,al. cranium : The skull of vertebrates. llad¾k,al ³ llad¾k,alénstVq¥wgkg. Crassulacean acid metabolism (CAM) CO (CAM) : A type of photosynthesis emtabUlIsGasIutRkas‘ulLaes ³ RbePTrsµIsMeyaKEdl 2 in which CO 2 is fixed at night into four-carbon acids; during the day, ®tUv)anP¢ab;eTAnwgGasuItEdlmankabUn4enAeBlyb;. enAeBléf¶ the stomata close and the carbon is sþÚma:tbiT ehIykabUn®tUv)anP¢ab;tamry³ vdþ Calvin . CAM CYyrukçCati fixed via the Calvin cycle; CAM helps plants conserve water and is eGayrkSaTwknigeRcInEtCalkçN³sMKal;rbs;rukçCatiduHenAtMbn;s¶ÜthYt often characteristic of xerophytic plants. Ehg. crenation : Shrinkage and dehydration of a cell that occurs eRkNasüúg ³ karsVitrYjnigedGIuRdatkmµénekasikaEdlekItmanenA when blood cells are placed in a solution of more than isotonic eBlekasikaQamRtÚv)andak;eTAkñúgsUluysüúgEdlmankMhab;xøaMgCag concentration and water moves out kMhab;GIusUtUnicehIyTwkRCabecjtamPñasekasika. through the cell membrane. cri-du-chat syndrome : A clinical syndrome in humans produced by a sheraKsBaØasMErkqµa ³ sheraKsBaØamnusSenAmnÞIrBüa)al Edl deletion of a portion of the short arm of chromosome 5. Afflicted ekIteLIgedaykardac;Ggát;mYyBIédxøIrbs;RkUmU:sUmTI 5. TarkEdlmanCMgW infants have a distinctive cry which enHyMxusEbøkBIFmµta KWmansMelgyMdUcqµa. sounds like that of a cat. cristae ( singular, crista) : The Crista tubular or vesicle shaped folds of cMraj ³ ¬Ékvcn³ ¦ pñt;ragdUcsrés² b¤dUcbMBg;rbs;Pñasxag the inner membrane of mitochondria; cristae contain kñúgénmItUkugRDI. vapÞúksIutURkUmnigsmasFatuepSg²eTotrbs;Rcv:ak;dwknaM cytochromes and other components eGLicRtugEdlCab;Tak;TgnwgsMeyaK ATP . of the electron transport chain that are involved in the synthesis of ATP. crop : 1. An enlargement at the 1- base of the esophagus in birds that EK ³ tMbn;rIkFMxagcugbMBg;Gaharrbs;;bkSIEdlsþúkGaharmuneBl stores food before passage to the 2- stomach. 2. A storage organ in the eTAdl;RkBH. srIragÁsþúkGaharénRbB½n§rMlayGaharrbs;dgáÚvxøÚn digestive system of most kg;PaKeRcIn. segmented worms. crop rotation : Planting different crops on a piece of land every dMNaMqøas; ³ viFIdaMdMNaMxus²Kñaerogral;qñaMenAelIdImYykEnøgedIm,I season to replace soil nutrients. dUrCICatidI ¬rkSaKuNPaBdIeGayenAdEdl ¦. crossing-over : Exchange of parts 2 between two homologous bNþÚrExVg ³ karpøas;bþÚrGgát;rvagRkUm:UsUmGUm:ULÚk . chromosomes. cross-reacting material (CRM) : Nonfunctional form of an enzyme, sarFatubg¥ak;Rbtikmµ ³ TMrg;Kµanmuxgarrbs;Gg;suImmYy Edlplit produced by a mutant gene, which is recognized by antibodies made edayEsnmuytg; EdlsÁal;edayGg;TIk EdlRtUv)anbegáIteLIgedIm,I against the normal enzyme. RbqaMgnwgGg;suImFmµta. cryptorchidism : A develop- mental condition in which the RKIbT½rKIDI ³ CasßanPaBEdlBgsVasminrMkilecjBIkñúgeBaHeTAkñúg testes do not migrate from the abdomen through the inguinal fg;sVas. canal to the scrotum.

C-terminal amino acid : The C terminal amino acid in a peptide GasIutGamIencug ³ GasuItGamIencugeRkaybg¥s;kñúgRcvak;buibTIt chain which carries a free carboxyl group. EdlmanRkumkabuksuIlesrI. cubic centimeter (cm 3or cc) : Unit of volume equal to 1 mL; the sgÞIEm:tKUb ³ ÉktaénmaDesµInwgmYymIlIlIRt. xñatEdleK preferred unit in medicine (for “cc” which the abbreviation “cc” is cUlcitþeRbIxagEpñkevC¢saRsþ nigsresrkat; . used). culm : The stem of grasses. edIm ³ edIménrukçCatiRkamIen. cultivar : A variety of plant that is selected for cultivation through KulTIv:a ³ RbePTrukçCatiEdl®tUv)aneRCIserIssMrab;kar hybridization and not found in . daMduHtamry³karbgáat; nigEdlKµanenAkúñgFmµCati. culture : 1. The complex behavior 1- patterns that distinguish a social, vb,Fm’; ³ KMrUGakb,kiriyasaMjaMu EdlbgðajnUvPaBedayELk ethnic, or religious group. 2. A 2- growth of living cells or micro- énsgÁm-CatiBn§ nigRkumsasna. karbNþúH ³ karbNþúHekasika organisms in a controlled rWmIRkUsarBagÁkayenAkñúgbrisßanRtYtBinitümYy. environment. cupule : Refers to the seed-bearing structure of an extinct group of KubBUl ³ TMrg;pÞúkRKab;énRkumrukçCatiEdlvinasputBUC ehAfa plants called the seed ferns bNѽgÁCatimanRKab;. Curie (Ci) : Amount of radiation 3.7x10 11 equal to 3.7 x 10 11 disintegrations KuyrI ³ brimaNrsµIµesµInwg bMENkkñúgmYyvinaTI. per second. cuticle : A tough outer surface that protects the bodies of parasitic 1- KuyTIKul ³ PñassVitxageRkAénsarBagÁkaydgáÚv brasitxøÜnsMEb:t flatworms from the digestive action of their hosts; a waxy covering on EdlkarBarTb;Tl;skmµPaBrMlayénFµÜlrbs;va. the epidermis of plants. 2- sMeNI ³ sarFatuRkmYnEdlRKbBIelIeGBIEDmrbs;rukçCati. cuticular wax : Wax that is embedded in a cuticle. RkmYnKuyTIKul ³ RkmYnEdlenACab;nwgsMeNI. cutin : The main waxy substance in a cuticle; it consists of KuyTIn ³ sarFatuRkmYnenAkñúgsMeNI. vapÞúkGasuItxøaj;GuIRduksuIl hydroxylated fatty acids that are linked together in a complex array. Edl®tUv)anP¢ab;CamYyKñakñúglMdab;tMerobsaMjaM. cutting : A type of vegetative propagation in which a leaf or xñat;bNþúH ³ RbePTénkardaMduHEdlsøwkrWEpñkmYyénedImRtUv)ankat;ecj piece of a stem cut from a parent plant and placed in water or damp BIrukçCatiem)anigdak;daMeTAkñúgTwk rWkñúgdI. rwsRBeyagk¾lUtlas;BI sand. Adventitious roots develop ekasikakMbüÚmEdlb:HnwgTwk rWdIenaH. from exposed cambium cells. cyanophycin : A polypeptide functioning as an energy reserve in süaNUhVIsIun ³ b:UlIbuibTItmanmuxgarCafamBlbMrugTukkñúg cyanobacteria. süaNU)ak;etrI. cyclic AMP (cAMP) : An (cAMP) important regulatory molecule in GaedNUsIunm:UNUpUsVatvdþ ³ mU:elKultMrUv b¤RtYtBinitüd¾sMxan; both prokaryotic and eukaryotic organisms. It controls the rate of EdlmanTaMgkñúgPavrs;GWkarIyU:tnigRbUkarIyU:t. vaRtYtBinitüdMenIrRbRBwtþ some cellular processes, produced eTArbs;ekasikamYycMnYn EdlekItmanenAkñúgekasikaxøH kñúgkareqøIytb in some cells in response to hormone binding to the cell eTAnwgGrm:UnCab;Pñasekasika. cAMP CaGñknaMsarTIBIr. membrane; cAMP is a second messenger.

cyclic photophosphorylation : The light-induced flow of electrons pUtUpUsV½rkmµvdþ ³ crnþbegáItBnøWrbs;eGLicRtugEdlmanRbPBBInig originating from and returning to ATP photosystem 1; cyclic eq

cytophotometry : A method of studying cells by staining selected sIutUpUtUemRTI ³ viFIénkarsikSaBIekasika edaybnSIBN’eTAelIEpñkEdl parts, such as the nucleus, and measuring how much light they eKeRCIserIs ¬]>éNVy:U ¦ ehIyvas;emIlBIbrimaNBnøWEdlva RsUb. absorb; the absorbance of stained karRsUbénRkUm:aTInEdl)anbnSIBN’enAkñúgéNVy:U KwsmamaRteTAnwg chromatin in a nucleus is proportional to the amount of DNA brimaN ADN EdlvapÞúk. it contains cytoplasm : A gel-like material filling all of the cell except the sIutU)aøs ³ sarFatuxab;Gn§ilEdlsßitenAeBjekasikaTaMgmUl elIk nucleus. ElgEtéNVy:U. cytoplasmic inheritance : Non-Mendelian form of inheri- tMNBUCtamry ³suItU)øas ³ TMrg;éntMNBUCminEmnm:g;Edl Edlva tance involving genetic information transmitted by self- Tak;TgnwgkarbBa©ÚnBt’manesenTic edays½VytMelIgeTVxøÜnÉgnUvFatu replicating cytoplasmic organelles suItU)øasdUcCa mItUkugRDI kørU:)øas.l. such as mitochondria, chloroplasts, etc. cytoplasmic male sterility (cms) : A male-sterile condition in which PaBGaeQµaledaysIutU)aøs ³ l½kçx½NÐeQµalGa EdlPaBGaenH sterility is controlled by mitochondrial (cytoplasmic) genes. ®tUv)anRtYtBinitüedayEsn ¬suItU)aøsµic ¦mItUkugRDI. cytosine : A nitrogen base with the ³ )asGasUtmanrUbmnþ C4H5ON 3 EdlmanenAkñúg ADN nig formula C 4H5ON 3 that is found in sIutUsIun DNA and RNA. See p. 319. ARN . emIlTMBr½ 319 . cytoskeleton : A system of microtubules and other proteins in eRKagq¥wgekasika ³ RbB½n§bMBg;tUc²nigRbUetGIunepSg²enAkñúgsIutU)aøs the cytoplasm that provides internal support for the cell. EdlbgáCaTMrxagkñúgrbs;ekasika. cytosol : Fluid interior of the cell, containing the ions and molecules sIutUsUl ³ GgÁFaturavxagkñúgekasikaEdlmanGIuy:ugnigm:UelKul that support life. Organelles are suspended in it. sMrab;RTRTg;CIvit ehIymanFatubgáekasikaGENþtkñúgenaH. D dalton : A unit of mass equal to 1.67 X that of the hydrogen atom, which is dal;tun ³ Éktama:sesµInwgm:asGatUmGuIRdUEsn EdlmanTMgn; -24 1.67 X 10 gram. A unit used in 10 -24 describing molecular weights. Rkam . ÉktaeRbIkñúgkarKNnaTMgn;mU:elKul. dark reaction : Part of ATP , NADPH photosynthesis that uses ATP, Rbtikmµggwt ³ EpñkénrsµIsMeyaKEdleRbI NADPH, and carbon dioxide to make glucose. nig]sµ½nkabUnicedIm,IplitKøúykUs. Darwinian fitness : See fitness. emIl fitness . Darwinism : Theory of evolution Charles Darwin by Charles Darwin, which states RTwsþIdakvIn ³ RTwsþIvivtþn_rbs; EdlEcgfa RbePT that different species of plants and animals have formed by rukçCati nigstVnanabgáeLIgedaytMNBUCénkarpøas;bþÚrsMParHesenTic inheritance of small genetic bnþicbnþÜcnigedayCMerIsedayFmµCati qøgkat;eRcInCMnan;. changes and natural selection over many generations. See natural sUmemIl natural selection . selection. data : The qualitative and quantitative observations collected Tinñn½y ³ KuNPaBnigbrimaNénkarsegátEdlRbmUl)anenAeBl during an experiment. BiesaFn_.

daughter cells : Two cells formed by cell ekasikakUn ³ekasikaBIrEdlRtUv)anbegáIteLIgedaycMENkekasika. division. daughter chromosomes : ADN Chromosomes produced by RkÚm:UsUmkUn ³ RkUm:UsUmekIteLIgedaykarsV½ydMeLIgeTV Edlman DNA replication that contain identical genetic information; Bt’manesenTicdUcKña nigekIteLIgbnÞab;BIkareFIVcMENkRkUmU:sUmenAvKÁ formed after chromosome division GaNapas. in anaphase. daughter nuclei : Two nuclei formed by mitosis. éNVy:UkUn ³ éNVy:UBIrEdlRtUv)anbegáIteLIgedaymItUs. daughter nucleus (or isotope) : Product of radioactive decay. The éNVy:UkUn ¬GIusUtUb ¦ ³ plitplénkarbMEbkviTüúskmµ. éNVy:Urbs; nucleus of a specific isotope is sometimes called a nuclide. GIusUtUbyfaRbePT CYnkalGacehAfanuyKøIt. day-neutral plant : A plant that is unaffected by the period of rukçCatiNWtéf¶ ³ rukçCatiEdlminTTYlrg\Ti§BlBIry³eBléf¶. daylight. de novo : Newly arising; synthesized from less complex karkekIteLIgfµI ³ EdlsMeyaKBIm:UelKulEdlminsUvmanPaB molecules rather than having been produced by modification of an sµúksµaj CaCagRtUv)anplitBIkMENERbénmU:elKulEdlmanRsab;. existing molecule. deamination : Reaction that α- removes the α -amino group from edGamInkmµ ³ RbtikmµdkRkúm GamInecjBIKøúytama:teGayCa glutamate yielding free ammonia Gam:Uj:ak;esrInig α− estUKøúytara:t. and α-ketoglutarate. death phase : The portion of some population growth curves in vKÁFøak;cuH ³ EpñkénExSekagbgðajBIkarlUtlas;rbs;b:UBuyLasüúg which the size of the population declines. EdlbgðajBIkarFøak;cuHnUvcMnYnrbs;b:UBuyLasüúg. death rate : The rate at which individuals in a population die. GRtasøab; ³ GRtaEdlÉktþ³enAkñúgb:UBuyLasüúgsøab;;. debranching enzyme : A type of enzyme that hydrolyzes the Gg;sIumpþac;sm<½n§ ³ RbePTGg;suImEdleFVIGuIRdUlIseTAelIcMNgsm<½n§ branched linkages of starch. GamIdug. decarboxylation : Loss Of C0 . 2 C0 This reaction takes place very edkabuksIulkmµ ³ kar)at;bg ; 2. RbtikmµenHgayekIteLIgcMeBaH readily for beta keto acids. ebtaestUGasIut. deciduous : Plants that shed their leaves annually. rukçCatiRCuHsøwkRbcaMqña M ³ rukçCatiEdlRCuHsøwkrbs;vaCaerogralqñaM. deciduous forest : A forest made of trees that annually shed all their éRBRCuHsøwkRbcaMqñaM ³ éRBEdlekIteLIgBIrukççCatiRCuHsøwkRbcaMqñaM. leaves. decomposer : An organism that breaks down dead organisms for its GñkbMEbk ³ Pavrs;EdlbMEbksarBagÁkaysøab;;edIm,IeFIVCaGaharrbs;va food; saprobe. rWehAfastVsIuexµac. deficiency : See deletion emIl deletion . deficiency disease : Any disorder caused by the lack of CMgwxVHCIvCati ³ vibtþiEdlbNþalmkBIkarxVHvItamIn sarFatuEr: b¤ one or more vitamins, minerals, or other essential nutrients in the diet. sarFatusMxan;epSgeTotEdlmanenAkñúgGahar. degenerate code : Term used to describe the genetic code, in which RkmminkMNt; ³ CaBaküeRbIedIm,IBN’naBIRkmesenTic Edlkñúg a given amino acid may be represented by more than one enaHGasuItGamIenmYy GacRtUv)antagedaykUdugeRcInCagmYy. codon.

dehydration : Formation of an alkene from an alcohol as a result edGIuRdatkmµ ³ karkekItGal;EsnBIGal;kuledaykar)at;bg;Twk. of the loss of water. dehydration synthesis reaction : A reaction that results in the RbtikmµsMeyaKrMedaHTwk ³ RbtikmµEdlbNþalmkBIkMNm:aRkUm:UelKul formation of a macromolecule when water is removed from edaymankarrMedaHTwkBICMnab;smasFatuTaMgBIr. between the two smaller component parts. deletion : A mutation in which a chromosomal segment is lost to the kar)at; ³ muytasüúgEdlGgát;RkUm:UsUmRtUv)andac;)at;eTAkñúgsIutU)aøs. cytoplasm. deme : A local, recognizable population that shows genetic DIm ³ b:UBuyLasüúgenAkñúgtMbn;sÁal;mYy EdlbgðajBIPaBxusKñaén differences from other local populations of the same species. sMPar³esenTiceTAnwgsMParesenTicrbs;B:UBuyLasüúgénRbePTdUcKña See subspecies . enAkñúgtMbn;epSgeTot. emIl subspecies . demersal : More dense than water and therefore sinking, as in the lickñúgTwk ³ EdlF¶n;CagTwk dUecñHliccuHeTAkñúgTwk dUcCaBgRtInig eggs of many fishes and amphibians. GMbUrkEgábCaeRcIn. demographic transition : A shift in birth and death rates that affects GnþrkaléncMnYnkñúgb:YBuyLasüúg ³ bMErbMrYlGRtaekIt nigGRtasøab; the size of a population. EdlCH\T§iBleTAdl;cMnYnrbs;b:UBuyLasüúg. denaturation : Alteration of the structure of a protein so that some kar)at;bg;lkçN³edIm ³ kareFIVeGaymankarpøas;bþÚrTMrg;rbs;RbUetGIun of its original properties are diminished or eliminated. EdleFIVeGaylkçN³edImrbs;vaRtUv)at;bg;. denatured DNA : DNA molecules ADN ADN that have been separated into single rla ³ CamU:elKul EdlRtUv)anpþac;ecjCaRcvak;eTal. strands. dendrites : Finely divided branches of a neuron that carry dg;RDIt ³ EmkExñgqµa²rbs;NWrU:n EdldwknaMrMejaceTAtYekasika. impulses toward the cell body. dendrochronology : The study of growth rings of trees to determine vg;sac;eQIviTüa ³ karsikSaBIkarlUtlas;énvg;sac;eQIedIm,IkMnt; past conditions. l½kçx½NÐBIGtIt³rbs;va. dengue : An infectious disease arbovirus B caused by a group B arbovirus, CMgWRKunQam ³ CMgWqøgEdlbNþalmkBIRkum usually transmitted by Aedes Aedes aegypti aegypti mosquitoes. Symptoms CaTUeTARtUv)ancMlgedaymUsxøa . eraKsBaØarYmman ³ include chills, headache, high RKunrga> QWk,al> RKunsn§M> QWsnøak;q¥wg nigsac;dMu nigeLIgknÞÜl. fever, pain in joints and muscles and rash. denitrifying bacteria : Bacteria that convert nitrates to nitrogen )ak;etrIbMElgnIRtat ³ )ak;etrIEdlbMElgnIRtateGayeTACa]sµ½n gas. GasUt. density : Mass per unit volume, commonly expressed in grams per dg;sIuet ³ ma:skñúgmYyxñatmaD CaTUeTAKitCaRkamkñúgmYysg;TIEm:RtKUb cubic centimeter or grams per milliliter. rWRkamkñúgmYymIlIlIRt.

density gradient centrifugation : A method of separating karEjkRbTajecjtamCMraldg;sIuet ³ viFIEjkl,ayma:RkUmU:elKul macromolecular mixtures by the use centrifugation in a medium edayeRbI karbgVilEjkRbTajecjmCÄdæanciBa©wm EdlmankMhab; whose concentration varies ERbRbYlbnþicmþg² BImat;bMBg;eTA)atbMBg;. smasFatul,aypøas;TIeTA gradually from top to bottom of the tube. Components of the mixture kMritkñúgmCÄdæanEdlmandg;suIetdUcKña. sárGMeBA b¤ essüÚmkørYCaFmµta move to a level in the medium whose density is the same. Sucrose RtUv)aneRbICamCÄdæan. or cesium chloride are usually used for the medium. density-dependent factors : Population controlling factors that ktþadg;sIuetminÉkraCü ³ ktþaRtYtBinitüÉltþ³BYk-RkumEdlTak;Tg are related to the size of the population. eTAnwgcMnYnrbs;Éktþ³BYk-RkumenaH. ] ³ enAeBlEdlcMnYnstVkan;Et eRcIn enaHstV EdlsIusac;CaGahark¾manlkçN³gayRsYlkñúgkarcab; Edr. density-independent factor : An environmental condition affecting ktþadg;sIuetÉkraCü ³ l½kçx½NÐbrisßanEdlCH\Ti§BleTAelI a population that is not related to its density. b:UBuyLasüúgEdlminTak;TgeTAnwgdg;suIetrbs;va. dentin : A hard bone-like material that surrounds the pulp cavity of a PøúkeFµj ³ rUbFaturwgdUcCaq¥wgEdleRsabB½T§CuMvijbNþÚleFµj. tooth. deoxyribonuclease : A class of ADN enzymes that breaks down DNA edGuksuIrIbUnuyekøGas ³ Gg;suImEdlbMEbk eGayeTACaGgát; into oligonucleotide fragments. GUlIkUnuyekøGUTIt. deoxyribonucleic acid : see DNA. GasIutedGuksIurIbUnuyekøGiuc ³ emIl DNA . deoxyribose : A 5-carbon sugar ADN molecule that is a component of edGuksIurIbUs ³ m:UelKulsárkabUn5 EdlCasmasFaturbs; . DNA. depolarized : Having lost the electrical difference existing manedb:Ulkmµ ³ kar)at;bg;PaBxusKñaénbnÞúkGKÁIsnIepSgKñaEdlekIt between two points or objects. eLIgenAcenøaHcMnuc 2b¤vtßú2. deposit feeding : Ingesting substrate (sand, soil. mud) and karsIudIl,ab; ³ karsIus‘ubRta ¬xSac; dI Pk;¦ nigkareFVIsmankmµEpñk assimilating the organic fraction. sarFatusrIragÁ. depressant : A drug that slows the functioning of the central nervous fñaMbnßyskmµPaB ³ fñaMBnüWtdMenIrkarrbs;RbB½n§mCÄmNÐlRbsaT. system. dermatoglyphics : The study of the surface ridges of the skin, esIrEs,kviTüaédeCIg ³ karsikSaBIépÞxagelIEs,k CaBiessEs,kéd especially of the hands and feet. nigeCIg. dermis : The layer of tissue directly under the epidermis. EDm ³ RsTab;CalikaEdlsßitenAxageRkamCab;nwgeGBIEDm. desert : A biome characterized by scant rainfall and widely spaced valxSac; ³ tMbn;CIv³EdlmanePøogminRKb;RKan; niglMhKµan vegetation. dMNuHrukçCati. desertification : The conversion of non-desert biomes into deserts. valxSac;kmµ ³ karpøas;bþÚrtMbn;CIv³EdlminEmnCa valxSac; eGayeTACatMbn;valxSac;. desiccation : Dehydration. kMhH ³ edsIuRdatkmµ.

desynapsis : The unpairing and separation of homologous karbMEbksIuNab; ³ karbMEbkKU nigkarbMEbkRkUm:UsUmGUm:ULÚkBIKña enA chromosomes when the synaptonemal complex eBlEdlkMepøcsIuNab;)anEbkecjBIKña. disintegrates detergent : Substance that has a cleaning action (surface-active sab‘UemSA ³ sarFatuEdlmamGMeBIsMGat ¬Pñak;garskmµelIépÞb:H ¦. agent). It has a long hydrocarbon chain and a polar end which is vamanExSGIuRdÚkabYEvgnigcugb:Ul EdlCaFmµtaCaGaj:úgs‘úlhVÚNat. usually a sulfonate anion. If the ebIsincugb:UlenaHCaGaj:uúgkabuksIuLat vaCasab‘UduM ¬sab‘UdusxøÜn ¦. polar end is a carboxylate anion, the detergent is called a soap. determination : An event that establishes and regulates a specific karkMNt; ³ RBwtþikarN_EdlbegáIt nigtMrUvKMrUyfaRbePTénskmµPaB pattern of gene activity. It determines the final form that a cell rbs;Esn. vakMNt;TMrg;cugeRkayEdlekasikanwglUtlas;eTACaGVImYy. will develop into. detritus : Particulate organic matter that sinks to the bottom of a kMeTckMTI ³ kMeTckMTIsrIragÁEdlliceTA)atTwk. body of water. deuteromycetes : Fungi that have no known sexual reproduction; dWetr:UmIEst ³ pSitEdleKminsÁal;BIkarbnþBUCedayePTrbs;va. most reproduce by conidia and otherwise have characteristics of PaKeRcInbnþBUCedaykUnIDI ehIyepSgeTotmanlkçN³dUc GasáÚmIWEst. ascomycetes. Deuteromycetes are dWetr:UmIEstk¾RtUv)aneKehApgEdrfapSitmineBjelj (Fungi also called Fungi Imperfecti. Imperfecti) . deuterostomy : Condition in which the embryonic blastopore dWetr:UsþÚmI ³ sßanPaBEdl)aøsþÚB½rrbs;GMRb‘Íyu:gbegáItTVarFMrbs;st V forms the anus of the adult animal; protostomy characteristic of chordates. See eBjv½yEdlCalkçN³Biessénsaxakred. emIl . protostomy . development : The stages that an organism goes through from when karlUtlas; ³ dMNak;kalEdlPavrs;qøgkat;BIeBlcab;epþIménCIvit it begins life until it reaches adulthood. rhUtdl;eBjv½y. diakinesis : The final stage of I meiotic prophase I in which the düaKIensIus ³ dMNak;bBa©b;énvKÁRbUpas énemyU:s EdlRkUmU:sUm chromosomes become tightly coiled and compacted and separate GgÁÜjxøIy:agxøaMg eLIgRkas; ehIydac;ecjBIKña. from one another. dialysis : Separation of colloidal materials from smaller ionic and düalIs ³ karEjksarFatukULÚGIutecjBIm:UelKulminsuT§ nigGIuy:ugtUc molecular impurities by diffusion of impurity ions or molecules Cag edaybnSayénGIuy:ug rWm:UelKulminsuT§tamPñasEdlPaKl¥it through a membrane that does not kULÚGIutminGacqøgkat;)an. let the colloidal particles pass. diaphragm : A large muscular sheet that separates the thoracic snÞ³RTÚg ³ snÞ³sac;dMuFMEdlEbgEckRbehagRTUgBIeBaH. cavity from the abdomen. See 322 p.322 emIlTMBr½ . diastereomers : These are stereoisomers that are not düaesþerGUEm ³ vaCaesþerGUGIusUEmrEdlminEmnCaeGNg;tüÚEm enantiomers, that is, they are not mirror images of each other. )ann½yfavaminEmnCarUbPaBqøúHKñaeTAvijeTAmk. diastole : Relaxation period between heart contractions. sMrakTUeTA ³ ry³eBlsMrakcenøaHkarkRnþak;énebHdUg.

diastolic blood pressure : The pressure present in a large artery sMBaFQameBlsMrakTUeTA ³ sMBaFQamkñúgsrésGakETFMenAeBl when the heart is not contracting. ebHdUgminkRnþak;. diatom : An autotrophic unicellular organism having a cell düatUem ³ Pavrs;sV½yCIBÉkekasikaEdlmanPñaseRKagsMbUreday wall with a high silicon content. CatisIulIs. diatomic molecules : Stable molecules comprising two atoms of m:UelKulDIGatUm ³ m:UelKulmanesßrPaBEdlekIteLIgBIGatUmBIrénFatu the same element. Oxygen (0 2), dUcKña. GuksIuEsn (0 2), GasUt (N 2), nigkør (C1 2)Ca]TahrN_énm:UelKul nitrogen (N 2), and chlorine (C1 2) are examples of diatomic DIGatUm. molecules. dicentric chromosome : A chromosome having two cen- RkUmU:sUmDIsg;RTic ³ RkUmU:sUmEdlmansg;RtUEmrBIr. tromeres. dicot : An angiosperm whose embryo has two cotyledons. See p. DIkUTIeldUn ³ Gg;süÚEs

dipeptide : A molecule made of two amino acids. DIbiubTIt ³ m:UelKulEdlbgáeLIgedayGasIuGamIenBIr. diploblastic : Possessing only two distinct tissue layers during DIbøÚ)aøs ³ EdlmanEtCalikaBIrRsTab;b:ueNÑaHenAdMNak;lUtlas;én embryonic development. GMRb‘Íy:ug. diploid : Having two of each type of chromosome; the somatic DIbøÚGIut ³ EdlmanRkUm:UsUmRbePTnImYy²cMnYnBIr. cMnYnRkÚmU:sUmrbs; number of chromosomes. ekasikalUtlas;. diplotene : A stage of meiotic I prophase 1 immediately after DIbøÚEtn ³ dMNak;mYyénvKÁRbUpas énemyU:sEdlekIteLIgPøam pachytene. In diplotene, one pair of sister chromatids begins separating bnÞab;BIvKÁ)a:KIEtn. kñúgvKÁDIbøÚEtn RkUma:TItbgb¥ÚnmYyKUcab;epþImEjk from the other, and chiasmata ecjBIKña ehIyküasµak¾GacemIleXIj. karrMuKgelIKñaenHeFVIclna become visible. These overlaps move laterally toward the ends of ecjeTAcMehogeq

disjunction : The separation of chromosomes at the anaphase stage karEjkRkUm:UsUm ³ karEjkecjBIKñaénRkUmU:sUmenAvKÁGaNapasén of cell division. cMENkekasika. disruptive selection : Simultaneous selection for CMerIsrMxan ³ CMerIsdMNalKñasMrab;epNUTIbEdlminEmnCalkçN³ phenotypes that are not average in a population, usually resulting in Fmµtakñúgb:UBuyLasüúg EdlCaTUeTAbNþaleGaymankarkekItBUCepSgKña the production of two different BIr. strains. distal convoluted tubule : A thin tube in a nephron leading from the bMBg;bt;Ebnq¶ay ³ bMBg;esþIgénenRhVúgcab;BIePñnGg;eleTAdl; loop of Henle to the collecting tubules which is mainly bMBg;TTYlTwkenam EdlmanmuxgarsMxan;kñúgkartMrUvbrimaNGIuRdUEsn responsible for regulating the nigGIuy:ugb:UtasüÚmkñúgQam. amount of hydrogen and potassium ions in the blood. distillation : Process in which the solution is heated until the material bMNit ³ lMnaMEdlsUluysüúgRtÚv)ankMedArhUtdl;;;rUbFatu of lower boiling point boils, leaves the solution, and is trapped and EdlmankMritBuHTabCageKBuH PayecjBIsUluysüúg nigkCakMNkTwk. condensed. disulfide : Product of thiol R-S-S-R oxidation, having the structure DIs‘ulPIt ³ plitplénGuksIutkmµtüÚlEdlmanTMrg;Ca . R-S-S-R. disulfide bond or disulfide bridge : A type of covalent bond between sm<½n§DIs‘ulPIt ³ RbePTsm<½n§kUv:aLg;rvagGatUms‘ulpYrénGasuItGamIen the sulfur atoms of separate amino acids in the same protein; disulfide epSgKñakñúgRbUetGuInEtmYy. cMNgDIs‘ulPItBRgwgTMrg;TI3énRbUetGIun. bonds strengthen the tertiary structure of proteins. diterpene : A compound that consists of four isoprene units DIETEBn ³ smasFatuEdlmanÉktaGIusUERbn 4 P¢ab;CamYyKña. linked together; gibberellins are gibberllins examples of diterpenes ]TahrN_³ . divergent evolution : A basic evolutionary pattern in which vivtþn¾rIk ³ KMrUvivtþn_mUldæanEdlkarEbgEckRbePTrbs;Éktþ³)aneFVI individual speciation events cause many branches in the evolution of eGayEbkEmkFageRcInenAkñúgkarvivtþn¾rbs;RkumPavrs;. a group of organisms. diversifying selection : Selection for the low frequency (extreme) CMerIseRcInEbb ³ kareRCIserIsepNUTIbeRbkg;TabxagelI nigxag phenotypes above and below the norm of the population; or eRkamniyménb:UBuyLasüúg b¤CMerIspÞúyBIepNUTIbEdlmaneRbkg;x

DNA ( deoxyribonucleic acid) : A ADN very large nucleic acid ¬GasIutedGuksIurIbUnuyekøGuic¦ ³ ma:RkÚmU:elKulGasIutnuyekøGuic macromolecule found in the cell nucleus, composed of repeating y:agFMenAkñúgéNVy:Uekasika EdlekIteLIgBIÉktadEdl²énsáredGuksIurI- units of deoxyribose sugar, bUs pUsVat nig)asGasUtenAkñúgkarbegáItRcvak;eTV. ADN pÞúkBt’man phosphate, and nitrogen bases in a double strand formation. DNA esenTicrbs;ekasika. vaRtYtBinitüTMrg;rbs;RbUetGuIn dUecñHRtYtBinitü contains the genetic information of a cell. It controls the structure of RbtikmµEdlBenøÓnedayGg;sIumTaMgGs;. proteins and therefore all enzyme catalysed reactions. DNA code : A sequence of three ADN : ADN 317 nucleotides of a DNA molecule. Rkm lMdab;;nuyekøGUTWt3rbs;m:UelKul . emIlTMBr½ . See p. 317. DNA footprinting : See ADN footprinting footprinting. hVÚ‘tRBInFIg ³ emIl . DNA gyrase : An enzyme that ADN AND functions during DNA replication sIur:as ³ Gg;suImEdlmanmuxgarenAeBlsVy½tMelIgeTV to reduce tension caused by DNA supercoiling. DNA gyrase edIm,IbnßyPaBtwg EdlbNþalmkBIkarGgÁÜjxøaMg. sIur:assMeyaK produces, then rejoins, ehIybnÞab;mkP¢ab;Rcvak;eTVEdldac;eLIgvij. double-stranded breaks. DNA ligase : A type of enzyme ADN that joins adjacent nucleotides lIkas ³ RbePTGg;suImEdlP¢ab;nuyekøGUTItEk,rKñaeGayCab;Kña together by catalyzing the ADN formation of sugar-phosphate edayCMrujkarbegáItsmç½n§sár-pUsVatenAkñúgRcvak; mYy. bonds in a strand of DNA. See p. emIlTMBr½319 . 319. DNA polymerase : An enzyme ADN ADN that bonds new DNA nucleotides b:UlIemr:as ³ Gg;sIumEdlP¢ab;nuyekøGUlTIt fµI²eGayCab;Kña together when they base-pair with ADN an existing DNA strand. enAeBlEdlvacab;KU)asCamYyRcvak; EdlmanRsab;. DNA replication : The process ADN : ADN) by which the genetic material sV½ydMeLIgeTV dMeNIrEdlsMPar³esenTic ¬ rbs;; ekasika (DNA) of the cell reproduces itself prior to its distribution to the next )ankekItedayxøÜnÉgmuneBlEckeTAeGayekasikaCMnan;eRkay. generation of cells. See p. 319. emIlTMBr½ 319 . DNase : Deoxyribonucleosidase, ADN an enzyme that breaks down DNA edGuksuIrIbUnuyekøGUsuIdas ³ Gg;suImmYyEdlkat; into fragments. See nuclease. eGayeTACaGgát;xøI². emIl nuclease . dolipore : A complex central pore occurring in the hyphal septa of dUlIB½r ³ RbehagkNþald¾saMjaMmYymanenAkñúgsnÞHx½NÐGuIhV many basidiomycete fungi; it is covered by a cap on both sides of rbs;pSit)asuIdüÚmIEstPaKeRcIn. vaRtUv)anRKbedaymYkenAsgxag the septum. snÞHx½NÐ. domain : A structural and functional portion of a polypeptide, dUemn ³ EpñkmuxgarnigTMrg;rbs;b:UlIbuibTItEdlGac®tUv)ancMlgeday which may be encoded separately by a specific exon. It has a globular ELk²BIKñaedayGicsunyfaRbePT. vamanTMrg;TIbIragdMumUl. tertiary structure. dominance hierarchy : A relatively stable, mutually lMdab;lubb¤lMdab;GMNac ³ lMdab;GaTiiPaBefreFobenAkñúgRkumEdl understood order of priority within a group. mankaryl;KñaeTAvijeTAmk. dominant : A term used to describe a gene or trait that lub ³ BaküeRbIsMrab;BiBN’naEsnmYyb¤lkçN³mYyEdlTb;mineGay prevents the expression of a recessive trait. lkçN³Gn;elcecj.

dominant allele : An allele that expresses itself and masks the GaELllub ³ GaELlEdlsMEdgecjlkçN³ nigbit)aMglkçN³ effects of other alleles for the trait. rbs;GaELlepSgeTotmineGaymankarsMEdgecj. dormancy : A period of inactivity during the development of a seed ry ³eBlenAes¶óm ³ ry³eBlKµanskmµPaBenAkñúgeBllUtlas; or spore. rbs;RKab;b¤s,:. dorsal : Located near the top or back of an animal. xñg ³ EdlsßitenACitEpñkxagelI b¤EpñkxageRkayrbs;stV. dorsal aorta : The portion of the aorta extending from the left GaGkxñg ³ Epñkrbs;GaGkEdlecjBIfteRkameqVgeTA. srésQam ventricle; a large dorsal blood vessel in invertebrates. FMenAxagxñgénstV\tq¥wgkg. dorsal fins : A pair of fins located along the dorsal midline of bony RBuyxñg ³ RBuymYyKUEdlsßitenAtambeNþayxñgrbs;RtIq¥wg. fish. dorsal nerve cord : A major nerve that lies along the notochord and BYrRbsaTxñg ³ srésRbsaTsMxan;EdlsßitenAtambeNþayBYrq¥wgxñg becomes the brain and spinal cord in chordates. ehIynwgkøayeTACaxYrk,alnigxYrq¥wgxñg cMeBaHkred. dosage compensation : A genetic mechanism that regulates the levels karTUTat;kMritEsn ³ clnkaresenTicEdltMrUvkMriténkarplitEsnenA of gene products at certain autosomal loci; this results in elILÚKusGUtUsUmxøHbNþaleGayGUmU:suIkUtlub nigeGetrU:suIkUtman homozygous dominants and het- brimaNénkarplitEsndUcKña. cMeBaHfnikstVskmµPaBedayécdnü erozygotes having the same amount of a gene product. In énRkUmU:sUm X mYyrbs;stVjI naMeGaymankMritesµIKñaénkarplitpl mammals, random inactivation of one X chromosome in females EsnEdlcMlgecjBIRkUm:UsUmkúñgstVeQµal nigstVjI. leads to equal levels of X chromosome- coded gene products in males and females. double bond : A covalent bond involving two pairs of electrons. sm<½n§eTV ³ sm½

down feathers : Small feathers that insulate a bird’s body against eramsMLI ³ eramtUc²EdlRKbdNþb;xøÜnbkSIsMrab;Tb;Tl;nwgkar)at;bg; heat loss. kMedA. Down’s syndrome (formerly Down ( ) Mongolism) : Human defects sheraKsBaaØ CMgwm:ugkUl ³ CMgWBIkMenItEdlrYmmanépÞmuxmin including abnormal facial features and mental retardation resulting Fmµta nigbBaØayWtbNþalmkBIkarelIsRkUm:UsUmTI21cMnYnmYy. from an extra copy of the 21 st emIl trisomy . chromosome. See trisom drone : A male bee. XµMúeQµal drug : 1. Any chemical used internally or externally for the 1- fñaM ³ FatuKImIEdleRbIxagkñúg rWxageRkAsMrab;Büa)al b¤karBarCMgW. treatment, cure, or prevention of disease; 2. a chemical that alters 2- fñaMejón ³ FatuKImIEdleFIVeGayERbRbYlmuxgarpøÚvcitþþ b¤pøÚvkay. the functioning of the mind or body. duodenum : The portion of the small intestine extending from the Kl;eBaHevontUc ³ kMNat;eBaHevontUcBITVareRkamRkBHeTAdl; ess‘uy- pylorus to the jejunum. Pancreatic juice and bile enter the duodenum num. rslMEBg nigTwkRbmat;cUleTAkñúgKl;eBaHevontUcedIm,ICYy to assist digestion. rMlayGahar. duplex DNA : DNA in a double – ADN ADN helix shape. Rcvak;eTV ³ EdlmanragCaregVleTV. duplication : See gene duplication karekIneTV ³ emIl . durophagous : Feeding upon hard material. Duyr:UhVahÁws ³ EdlsIurbs;rwg. dyad : The products of tetrad separation or disjunction at the first düat ³ plitplEdl)anmkBIkareRbHtambeNþayrbs;etRtatenA meiotic prophase. Consists of two I sister chromatids joined at the vKÁ³RbUpas énemyU:s. vamanRkUma:TItbgb¥ÚnBIrP¢ab;KñaenARtg;sg;RtUEm. centromere. dynamic equilibrium : The condition in which molecules are lMnwgDINamic ³ l½kçx½NÐEdlm:UelKulRtUv)anEckesµIKña dUecñHeFIV equally dispersed, therefore movement is equal in all directions. eGaymanclnaesµIKñaeTARKb;Tis. dynein : A large contractile protein that forms the connecting side arms daynIn ³ RbUetGuInk®nþak;d¾FM EdlbegáItédP¢ab;cMehog nigkaMrvag and spokes between microtubules in flagella kUnbMBg;kñúgpøaEsl. E E. coli : see Escherichia coli. GIuxUéL ³ emIl Escherichia coli . ear : The sense organ for hearing, balance and acceleration in Rtecok ³ srIragÁvijaNsMrab;karl,W lMnwg nigsMTuHénstVq¥wgkg. vertebrates. See auditory canal, auditory, canal, eustacian tube, tympanic, membrane , eustachian tube, tympanic sUmemIl membrane, cochlea, oval cochlea, oval window, ossicle . window, ossicle. early (spring) wood : Wood produced in the spring; usually sac;eQIniTaXrdUv ³ sac;eQIEdlkekItenAniTaXrdUv EdlCaFmµta characterized by relatively large cells. sMKal;edayekasikaFM²KYrsm.

echolocation : A method of detecting prey and obstacles using eGkUdMeNAkEnøg ³ viFIrkrMBanigdwgBI]bsKÁepSg²edayeRbIrlk reflected sound waves. eg used by bats, dolphins and whales. sMelgerpøic. ]TahrN_ ³ eRbIedaystVRbeCov RCwg dUhVaMg nig )aELn. ecological isolation : A genetic isolation mechanism that prevents karbMEbkeGkULÚsIu ³ clnkarbMEbkesenTicEdlkarBarmineGayman interbreeding between individuals of the same species because they karbgáat;rvagRbePTdUcKña edaysarvars;enAdMbn;epSgKña. eKehA live in different areas; also called mü:ageTotfakareRCIserIskEnøgrs;enA. habitat preference. ecological race : A race composed of many similar variants of the BUCeGkULÚsIu ³ BUCEdlmanÉktþ³bMErbMrYlRsedog²KñaCaeRcInénRbePT same species in several local populations distributed over a EtmYykñúgb:UBuyLasüúgenAnwgkEnøgEdlEbgEckBaseBjPUmisaRsþFM relatively large geographic area. KYsm. : The study of the relationship between organisms eGkULÚsIu ³ karsikSaGMBITMnak;TMngrvagPavrs;nigbrisßanrbs;va. and their environment. EcoRI : An example restriction RI enzyme that comes from the GIuxU ³ ]TahrN_BIGg;suImkMhitmYy Edl)anmkBI)ak;etrI bacterium Escherichia coli; this Escherichia coli ADN: GAATTC restriction recognizes the DNA . karkMhitenH sÁal;lMdab; sequence GAATTC, then cleaves it bnÞab;mkGg;sIumenHkat;Rcv:ak; ADN enAcenøaHkanIn nigGaednIn. between the guanine and the adenine. : Community of organisms and their entire physical zanRbB½n§ ³ shKmn_Pavrs; nigbrisßanCMuvijrbs;va. environment. ecotype : An individual group of plants adapted to a specific eGkUTIb ³ RkumÉktþ³rukçCatiEdlsMrbxøÜneTAnwgshKmn_yfaRbePT community within its overall distribution. kñúgr)ayTUeTArbs;va. ectoderm : The outer layer of cells in an embryo that forms epidermal, GictUEDm ³ RsTab;ekasikaxageRkArbs;GMRb‘Íy:ug EdlbgábegáIt nervous, and sensory organs and tissues. eGBIEDm RbB½n§RbsaT srIragÁviBaØaN nigCalika. ectohormone : A pheromone; a substance secreted externally by an GictUGrm:Un ³ køinkøÜn . sarFatubeBa©jmkeRkAedayPavrs;Edlman organism to influence the behavior of other organisms; an ectocrine. \T§iBlelIGakb,kiriyarbs;Pavrs;epSgeTot. GictURKIn. ectomycorrhizae : Mycorrhizae that develop externally and do not GictUmIkUrIs ³ mIkUrIsEdllUtlas;enAxageRkA ehIyminduHeRCót penetrate to the interior of the cells they surround. cUleTAEpñkxagkñúgrbs;ekasikaEdlvaB½T§CMuvijeT. ectoplasm : The cortex of a cell or that part of cytoplasm just under GictU)øas ³ EpñksMbkrbs;ekasika rWEpñkrbs;sIutU)aøs EdlsßitenA the cell surface; contrasts with endoplasm. Cab;pÞal;BIeRkamPñasekasika. pÞúyBIBaküGg;dU)øas. ectothermic : Animals that regulate their body temperature by GictUETmic ³ stVEdltMrUvsItuNðPaBxøÜnvaedaybMlas;TIeTAkEnøg moving to places where they can be most comfortable. EdlvaGacrs;enAedaysuxRsYl)an. edaphic factor : A soil factor. ktþadI edentulous : Lacking teeth. KµaneFµj

Edwards syndrome : A human Edwards genetic mutation caused by trisomy sheraKsBaaØ ³ muytasüúgesenTicmnusSbgáeLIg of chromosome 18. Symptoms include a long skull and severe edayRTIsUmIénRkUmU:sUmTI18. eraKsBaØarYmmanq¥wgEvg mental retardation. nigmanbBaØaGn;fy y:agxøaMg . effector molecule : Small, biologically active molecule that m:UelKuleGpicT½r rWm:UelKulskmµ ³ CamU:elKulCIvsaRsþskmµtUc² acts to regulate the activity of a protein by binding to a specific EdltMrUvskmµPaBRbUetGuInedayP¢ab;eTAelIFµÜlyfaRbePT receptor site on the protein. enAelIRbUetGuIn. egg : The female reproductive cell. kaEm:tjI ³ ekasikabnþBUCjI. egg apparatus : A group of 3 usually three cells in an embryo Fatubgárbs;kaEm:tjI ³ RkumekasikaEdlCaTUeTAmanekasika sac, one of which is the egg and 1 2 two of which are synergids. enAkñúgfg;GMRb‘Íy:ug EdlkñúgenaH CakaEm:tjI nig eTotCasuIEnsuIt. egg tooth : A small structure on the end of a hatching bird’s beak or eFµjs‘ut ³ TMrg;tUcmYyenAcugcMBuHbkSIeBljas; b¤enAxagcugRcmuHlµÚn on the tip of a hatching reptile’s nose that is used in pecking eBljas;EdlvaeRbIsMrab;ecaHTMlaysMbks‘ut. through the egg shell. ejaculation : The release of sperm cells and seminal fluid kar)aj;ecjmkeRkA ³ karbeBa©jTwkkameTAeRkAtamlwgÁrbs;burs. through the penis of a male. electric charge : Presence of excess positive or negative parti- bnÞúkGKÁisnI ³ vtþmanPaKl¥itviC¢manrWGviC¢manelIsenAkñúgrWelIvtßúmYy. cles in or on an object. Objects with opposite electric charge attract vtßúEdlmanbnÞúkGKÁisnIpÞúyKñaTajKñaeTAvijeTAmk. cMENkÉvtßúEdl each other, whereas objects of the manbnÞúkdUcKñaRcanKñaeTAvijeTAmk. same electric charge repel each other. electrical conductivity : Ability of a material to transfer electric PaBcMlgGKÁisnI ³ lT§PaBbBa¢ÚnbnÞúkGKIÁsnIénrUbFatu. rUbFatuEdl charge. A material that conducts electricity has either mobile cMlgGKiÁsnImaneGLicRtúg rWGaj:úg nigkacugcl½t. electrons or mobile anions and cations. electrochemical gradient : The combination of a concentration CMraleGLicRtUKImI ³ bnSMénCMralkMhab; nigCMralGKÁisnIrbs;GIuy:ug gradient and an electrical gradient of ions across a membrane. qøgkat;Pñas. electrochemical series : Listing of half-reactions in order of es‘rIeGLicRtÚKImI ³ taragBak;kNþalRbtikmµkñúglMdab;ekIneLIgénkar increasing tendency to gain electrons. Used to predict whether cab;ykeGLicRtúg. taragenHRtÚv)aneRbIedIm,I)a:n;sµanfaetIRbtikmµdwknaM a given electron-transfer reaction eGLicRtúgnwgdMeNIrkarrWeT. Bak;kNþalRbtikmµNamYyGacrMedaH will proceed. Any half-reaction can remove electrons from any eGLicRtúgBIBak;kNþalRbtikmµmYyepSgeTotEdlenAeRkamvakñúges‘rI. half-reaction below it in the series. electrogenic pump : An active transport protein that transports sñb;eGLicRtUEsnic ³ RbUetGuIndwknaMskmµ EdldwknaM ¬sb; ¦ GuIy:ug (pumps) ions against their concentration gradient; the main bRBa©as;CMralkMhab;. sñb;eGLicRtUEsnicEdlsMxan;cMeBaHrukçCati electrogenic pumps in plants are KWsñb;RbUtug. proton pumps. electrolysis : Use of electric current to break molecules into eGLicRtÚlIs ³ kareRbIcrnþGKiÁsnIedIm,IbMEbkm:UelKuleGayeTACa their component elements. FatupSMrbs;va.

electrolyte : Solution that contains ions and conducts electricity. eGLicRtÚlIt ³ sUluysüúgEdlmanGIuy:ugnigcMlgcrnþGKiÁsnI. electrolytes : Ionic compounds dissolved in water. Their proper eGLicRtUlIt ³ smasFatuGIuy:ugEdlrlaykñúgTwk. lMnwgRtwmRtUv balance is essential to life. rbs;vaKWmansar³sMxan;cMeBaHCIvit. electromagnetic radiation : Form of wave motion comprising rsµIeGeLicRtÚma:ejTic ³ sNæanclnarlkénEdnGKÁisnInigEdn alternating electric and magnetic (3 X 10 8 m/s) X fields that travels at an extremely ma:ejTicqøas;EdlelOnbMput . ]TahrN_³ BnøW-kaMrsµI / high speed (3 X 10 8m/s). eg. light, kaMrsIµháama: kaMrsµIsVayGu‘lRta BnøWGaMgR)aRkhm rlkviTüú.l. X-rays, Gamma( γ) rays, UV(ultra- violet), IR(infra-red), radio etc. electron : A very small, negatively charged particle that moves outside eGLicRtug ³ pg;manbnÞúkGviC¢manEdleFIVclnaenAxageRkAéNVy:U the nucleus and can be relatively 1/1837 easily removed from an atom. The nigGacpþac;ecjBIGatUm)any:aggay. ma:srbs;eGLicRtúgKW charge of an electron is – 1 and its énma:sGatUm GIuRdÚEsnehIybnÞúkvaesµI – 1 . mass is 1/1837 that of a hydrogen atom. electron acceptor : A particle that can accept electrons from another GñkTTYleGLicRtug ³ pg;EdlGacTTYleGLicRtugBIpg;;epSgeTot. particle. electron microscope : A microscope that uses a beam of mIRkÚTsSn_eGLicRtUnic ³ mIRkUTsSn_EdleRbIkaMrsµIWeGLicRtugCMnYs electrons instead of light as its source of illumination. BnøWFmµtaCaRbPBBnøWrbs;va. electron transfer : Transfer of an electron from one atom to another, benÞreGLicRtúg ³ karepÞreGLicRtúgBIGatUmmYyeTAGatUmmYyeTot generally to achieve a stable electron configuration. CaBiessedIm,IeFVIeGayrUbsNæaneGLicRtúgmansßirPaB. electron volt (eV) : Unit describing the energy of an v:uleGLicRtúg ³ ÉktaBN’naBIfamBlrbs;eGLicRtúg. electron. electron-dot method : Graphic shorthand for writing the viFIdMeNAcMNuceGLicRtúg ³ RkahVictagcMNucsMrab;bBa¢ak;nUvkar outer-group electron complement of an atom. Used principally for bMeBjRkúmeGLicRtúgxageRkAénGatUmehIyRtÚveRbICasMxan;edIm,IbgðajBI showing electron sharing in kardak;rYmeGLicRtúgkñúgbenÞreGLicRtúg b:uEnþminkMNt;c,as;elIGrb‘Ítal; electron transfer but does not specify the orbitals involved. See cUlrYmeT. emIl Octet rule, Valence shell electron pair repulsion Octet rule, Valence shell electron pair repulsion theory. theory . electronegativity : Measure of an atom’s ability to attract electrons. kMriteGLicRtÚGviC¢man ³ TMhMénlT§PaBrbs;GatUmmYykñúgkarTaj The type of chemical bond that forms between two atoms can be eGLicRtúg. RbePTsm<½n§KImIEdlekIteLIgrvagGatUmBIr ehIyGacyk predicted by computing the Cakar)anedayKiteTAelIPaBxusKñaénkMriteGLicRtÚGviC¢man. difference in their electroneg- ativities. electron-filling series : System by which orbitals are filled with es‘rIénkarbMeBjeGLicRtúg ³ RbB½n§Grb‘Ítal;EdlRtÚv)anbMeBjCamYy electrons, beginning with orbitals of lowest energy. eGLicRtúgedaycab;epþImeTAelIGrb‘Ítal;EdlmanfamBlTabbMput.

electron-transport chain : Series of electron carriers that transport Rcvak;dwknaMeGLicRtúg ³ es‘rIénGñkdwknaMeGLicRtúgEdlbBa¢ÚneGLic- electrons from the reduced RtúgBIkUGg;sIumerdukr NADH nig FADH 2eTAeGayGuksIuEsn. famBl coenzymes NADH and FADH 2 to oxygen. Energy released during Edl)anrMedaHkñúglMnaMenHeFVIeGaymankarsMeyaK ATP BI ADP nig this process enables synthesis of ATP from ADP and P. Electron pUsVr. dMNwknaMeGLicRtugKWmansar³sMxan;sMrab;rsµIsMeyaK nigdegðIm transport is vital for photosynthesis and aerobic respiration. manxül;. electrophilic substitution reaction : Reaction in which an RbtikmµCMnYseGLicRtÚPIl ³ RbtikmµEdleGLicRtÚPIlCMnYs electrophile (E’) substitutes for an H on an aromatic ring. GIuRdÚEsnenAelIsiucGar:Uma:Tic. electrophoresis : A technique used to separate a mixture of molecules eGLicRtÚpers ³ viFIeRbIedIm,IEjkl,aym:UelKulEdlmanbnÞúkGKÁisnI that have different electrical charges (e.g. amino acids, peptides, xusKña ¬]TahrN¾ ³ GasuItGamIen buibTIt RbUetGuIn GasuItnuyekøGuic ¦ proteins, nucleic acids), by their edayclnarbs;vaqøgkat;vKÁminefrmYyenAkúñgEdnGKÁisnI. movement through a stationary phase in an electrical . element : A substance made of only one kind of atom that cannot Fatu ³ sarFatuEdlbgáeLIgedayGatUmEtmYyRbePT EdlminGac be broken down by chemical means to simpler substances. Each bMEbk)antamviFIKImIeGayeTACasarFatugayCagva. FatunImYy² element is unique. manlkçN³eTal. embryo : An early stage of a developing organism. GMRb‘Iy:ug ³ dMNak;kaldMbUgénkarlUtlas;rbs;Pavrs;. embryo sac : The common name for the female gametophyte of fg;kMN rWfg;GMRb‘Íy:ug ³ eQµaHTUeTAsMrab;kaEm:tUPItjIrbs;rukçCatiman flowering plants. páa. embryology : The study of an organism’s development from the GMRb‘Íy:ugviTüa ³ karsikSaBIkarlUtlas;rbs;Pavrs; cab;BIdMNak;sIukUt zygote or fertilized egg stage. b¤s‘utbgákMeNIt. emigration : The movement of individuals out of an area. bMlas;lMenA ³ bMlas;TIrbs;Éktþ³TaMgLayecjBIkEnøgmYy. emphysema : A condition in which the alveoli in the lungs are CMgWEbkkUnfg;sYt ³ sßanPaBEdlkUnfg;sYtenAkñúgsYtRtUvFøúHFøayeFIV ruptured, thus interfering with oxygen intake. eGayrMxandl;kardwknaMGuksIuEsn. empirical evidence : The information gained by observing an PsþútagBiesaFn_ ³ Bt’manEdlTTYl)anBIkarsegátCak;Esþg. event. empirical formula : Simplest ratio of atoms in a compound, usually rUbmnþGMBIricrWrUbmnþgay ³ pleFobgaybMputénGatUm EdlmanenAkñúg derived from experimental percentage composition data. smasFatumYy CaFmµta)anmkBITinñn½yénsmasPaBCaPaKry BiesaFn_. emulsion : A colloidal system in which both phases are liquids. eGmulsüúg ³ RbB½n§kULÚGIutEdlRsTab;TaMgBIrCavtßúrav. enamel : A very hard layer of material that covers the crown of a kacaeFµj ³ RsTab;sarFaturwgEdleRsabedImeFµj. tooth. enantiomers : Pair of isomers that are mirror images of each other and eGNg;tüÚEm ³ KUGIusUEmEdlCarUbPaBqøúHKñaeTAvijeTAmknigminRtÜt are not superimposable; a pair of chiral molecules. elIKña. vaCaKUénm:UelKulKIra:l;.

encystment : The secretion of a protective outer covering that kMNKIs ³ karbegáItsMbkkarBarxageRkAsMrab;eGaystV\tq¥wgkgtUc² permits some small invertebrates to withstand exposure to extreme mYycMnYnGacTb;Tl;nwgbrisßanminl¥dUcCakMehH nighVÚgstVeRcInkuHkr environmental stresses, such as eBk. desiccation and overcrowding. endemism : Property of being endemic i.e., found only in a tamtMbn; ³ lkçN³tamtMbn; ¬]TahrN_ ³ RbTHeXIjEtenAtMbn; particular region. NamYy ¦. endergonic : A reaction that requires an input of energy before RbtikmµeGnD½rhÁÚnic ³ RbtikmµEdlRtUvkarfamBlmunnwgRbtikmµekIt it will occur; endergonic reactions never occur spontaneously. eLIg. RbtikmµRtUvkarfamBlminEdlekIteLIgedayÉg²eT. endocarp : The innermost layer of simple fleshy fruits; the endocarp Gg;dUkab ¬bNþÚl ¦ ³ RsTab;kñúgbMputénEpøsac;Fmµta. can be soft, as in tomatoes, or hard and stony, as in peaches. vaGacTn;dUcenAkñúgEpøeb:ge)a:H b¤GacrwgdUcCAenAkñúgEpøeb:s. endocrine gland : A ductless gland that pours its secretions RkeBjbeBa©jkñúgb¤RkeBjGg;dURKIn ³ RkeBjKµanbMBg;;naMEdl directly into the bloodstream. beBa©jsarFaturbs;vacUleTAkñúgsrésQamedaypÞal;. endocrine system : A number of glands that communicate with one RbB½n§beBa©jkñúgb¤RbB½n§Gg;dURKIn ³ RkeBjCaeRcInEdlTak;TgKñaeTA another and other tissues through chemical messengers transported vijeTAmk nigeTACalikaepSgeTottamry³sarFatuKImIEdldWknaMBas- throughout the body by the eBjsarBagÁkayedayRbB½n§rbt;Qam. circulatory system. endocytosis : The transport of materials into cells by vesicles. Gg;dUsuItUs ³ kardwknaMsarFatucUleTAkñúgekasikaedayfg;sIutU)aøs. ]TahrN_³ pakUsIutUs. endoderm : An embryonic tissue layer that forms the wall of the Gg;dUEDm ³ RsTab;CalikaGMRb‘Íy:ugEdlbegáItPñasénRbB½n§rMlay digestive system. Gahar. endodermis : The innermost ring of cortex cells in a plant root and in Gg;dUEDmmIs rWGg;dUEDm ³ rgVg;RsTab;ekasikaxagkñúgbMputénEpñk certain plant stems. sMbkrwsrukçCati nigkñúgedImrukçCatimYycMnYn. endogenote : In bacterial sexual process, the part of the Gg;dUesNUt ³ kñúgdMeNIrbnþBUCedayePTrbs;)ak;etrI CaEpñkRkUm:UsUm chromosome of the recipient cell ADN that is homologous to the incoming énekasikaGñkTTYl EdlCaGUm:ULÚkeTAnwg EdlcUlmk. DNA. endometrium : The lining of the uterus in humans. PñasesIms,Ún b¤Gg;dUEm:t ³ Pñasxagkñúgrbs;s,Ún cMeBaHmnusS. endomitosis : Chromosomal replication that is not accompanied Gg;dUmItUs ³ karsV½ytMelIgeTVRkUmU:sUm EdlKµancMENkéNVyU: b¤ by either nuclear or cytoplasmic division. cMENksuItU)øas. endomycorrhizae : Mycorrhizae that develop within the interior of Gg;dUmIkUrIs ³ mIkUrIsEdllUtlas;enAxagkñúgekasika. cells endonuclease : An enzyme that hydrolyzes internal phosphodiester Gg;dUnuyekøGas ³ Gg;suImEdleFVIGuIRdUlIssm<½n§pUsVr½DIeGEsÞEpñkxag bonds in a polynucleotide chain or nucleic acid molecule(DNA or kñúgénRcvak;bU:lInuyekøGUTIt b¤mU:elKulGasuItnuyekøGuic. RNA).

endoplasm : That part of cytoplasm that surrounds the Gg;dU)aøs ³ Epñkrbs;suItU)øasEdlB½TÞCMuvijéNVy:U. nucleus closely. endoplasmic reticulum (ER) : Membranous organelle within the erTIKuyLÚmGg;dU)aøs ³ FatuekaskaEdlmanPñasenAkñúgekasika eucaryotic cell where some of the cellular synthesis and transport of GWkarIy:Ut EdlCakEnøgEdlsMeyaKekasikamYycMnYn kardwknaMRbUetGIun proteins and lipids occurs. The niglIBItekItman. épÞxageRkAénPñasrbs;manrIbUsUm. ¬erTIKuyLÚm outer surface of the membranes may be ribosome- studded (rough Gg;dU)øaseRKIm ¦ b¤KµanrIbUsUm ¬erTIKuyLÚmGg;dU)øasrlag ¦. ER) or smooth ER. endopolyploidy : The increase in chromosome sets that results from Gg;dUbU:lIbøÚGuIDI ³ kMenIncMnYnRkUmU:sUmEdlbNþalmkBIsVy½tMelIgeTV endomitotic replication within somatic nuclei. Gg;dUmItUskñúgéNVyU:ekasikalUtlas;. endoskeleton : An internal supporting framework of an eRKagq¥wgkñúg ³ eRKagEdlRTRTg;Epñkxagkñúgrbs;stV. animal. endosperm : A triploid tissue containing stored food for the Gg;dUEs

enhancer : A sequence that increases the transcriptional GñkbegáIn rWGñkCMruj ³ tMNlMdab;EdlbegáInskmµPaBcMlgRkm activity of nearby structural genes. Similar sequences that enhance rbs;EsnTMrg;EdlenAEk,rKña . tMnlMdab;RsedogKñaEdlbegáInkarcMlg transcription have been identified RkmRtUv)aneKrkeXIjenAkñúgesNUmrbs;ekasikaGWkarIyU:t. GñkbegáIn in the genomes of eukaryotic cells. / / Enhancers can act over a distance GaceFVIskmµPaBkúñgcMgayCag1000KU)as nigGacmanTItaMg % b¤ # eTA of thousands of base pairs and can be located 5’ or 3’ to the gene they nwgEsnEdlvaman\T§iBleTAelI dUecñHehIy)anCamanPaBxusKñaBI affect, and thus are different from promoters. RbUmU:Tr½. enhanson : The DNA sequence ADN that represents the core sequence of tMNlMdab;sñÚl ³ tMNlMdab; EdltageGaytMNlMdab;sñÚlén an enhancer. GñkbegáIn b¤GñkCMruj. enterocoel : A type of coelom that is formed by the out-pouching of a Gg;etr:UEsl ³ RbePTsWLÚmEdlRtUv)anbgábegáIteLIgedayfg;ptecj mesodermal sac, from the endoderm of the primitive gut. kñúgemsUEDmBIGg;dUEDm EdlCaedImkMeNIténeBaHevon. enterocoelomate : Those that have an enterocoel, such as the Gg;etr:UsWLÚm:at ³ stVEdlmanGg;etr:UEs‘l dUcCastVBBYkeGKINUEDm echinoderms and the vertebrates. nigstVq¥wgkg. enterocoely : Formation of a coelom through outpocketing of kMNGg;etr:UEsl ³ karkekIténsWLÚmedaykarptecjénGakg;etr:ug the inner portion of the archenteron (Deuterostomes) in some animals (deuterostomes). cMeBaHstVmYycMnYn . entrainment : The process by which a regular repetition of some karhVwkhat;skmµPaB ³ dMeNIrekIteLIgmþgehIymþgeTot CaeTogTat; signal (e.g., light, dark) produces a circadian rhythm that remains énsBaØamYycMnYn ¬ ]> PøW ggwt ¦ begáItcgVak;skmµPaBRbcaMéf¶ EdlrkSa synchronized with the same cycle lMnaMdUcKñaeTAnwgvdþénktþahVwkhat;. as the entraining (i.e., modifying) factor. entropy : The amount of order in a system. The tendency for the Gg;RtÚBI ³ brimaNénsNþab;Fñab;enAkñúgRbB½n§mYy. TMenarBIPaBman to go from more order to less order. Energy must be used to sNþab;Fñab;CageTAPaBminsUvmansNþab;. famBlRtÚv)aneRbIedIm,I temporarily prevent this tendency karBarTMenarenHCabeNþaHGasnñcMeBaHPavrs;. in living organism. environment : All external factors that make the surroundings of an brisßan ³ ktþaxageRkATaMgGs;EdlbegáItmCÄdæanCuMvijPavrs;. organism. environmental resistance : The sum of all the limiting environ- karRbqMagénbrisßan ³ ktþaRBMx½NÐsrubTaMgGs;énbrisßanEdlkarBar mental factors that prevent a population from reaching its biotic b:UBuyLasüúgmineGayeTAdl;b:Utg;EsülCIvitrbs;va. potential. enzymatic competition : Competition among several karRbECgénGg;sIum ³ karRbECgKñarvagGg;sIumepSg²KñaCaeRcInedIm,I different available enzymes to combine with a given substrate P¢ab;eTAnwgs‘ubRsþaNamYy. material. enzyme : A protein substance produced by living cells capable of Gg;sIum ³ sarFatuRbUetGIunplitedayekasikars;EdlGacbegáInel,Ón speeding up specific chemical changes such as hydrolysis, bMElgKImIyfaRbePT dUcCaGIuRdÚlIs GuksIutkmµ rWerdukmµ b:uEnþvaminRtÚv oxidation, or reduction, but is )anbMElgeTkñúglMnaMenH. katalIkrCIvsa®sþ. unaltered itself in the process; a biological catalyst.

enzyme system : An enzyme or group of enzymes whose synthesis RbB½n§Gg;suIm ³ Gg;suIm1 b¤RkumGg;suImEdlkarsMeyaKrbs;vaRtUv)an is regulated by the intracellular concentration of certain tMrUvedaykMhab;kúñgekasikaénemtabUlItxøH². metabolites. enzyme-substrate complex : A temporary molecule formed when kMepøcGg;sIum-s‘ub®sþa ³ m:UelKulbeNþaHGasnñEdlekIteLIgenA an enzyme attaches itself to a substrate molecule. eBlEdlGg;sIumP¢ab;xøÜnvaeTAnwgm:UelKuls‘ubRsþa. eosinophil : One type of white blood cell in the group of eGGUsIuNUPIl ³ RbePTmYyéneKalikas énRkumRkanuyLÚsIut Edl granulocytes characterised by acid dye eosin staining red with the acidic dye sMKal;edaykarcab;BN’RkhmenAeBlbnSIúBN’CamYy . eosin. They help to destroy internal vaCYybMpøajbrasuItxagkñúg. parasites. epicontinental sea (epeiric sea) : Sea extending within the margin of smuRTelITVIb ³ smuRTEdllatsn§wglycUleTAkñúgEdndIeKak. a continent. epicotyl : The part of an embryonic plant above the RtÜyBnøk ³ Epñkrbs;GMRb‘Íy:ugrukçCatisßitenAxagelIkUTIeldug Edlnwg cotyledons that will become the leaves and stem. lUtlas;eTACasøwknigedIm. epicuticular wax : The outermost layer of wax in a cuticle. RkmYnelIsMeNI ³ RsTab;RkmYneRkAbMputénsMeNI. epidemic : The rapid and uncontrollable spread of a disease. CMgWratt,at ³ CMgWEdlraldalelOn ehIyEdlminGacRKb;RKg)an. epidermis : A specialized outer layer of cells that protects and eGBIEDm ³ RsTab;ekasikaÉkeTsxageRkAEdlmanmuxgarkarBarnig covers surfaces. RKbdNþb;elIsarBagÁkay. epididymis : A coiled tube where sperm is stored leading from the eGBIDIDIm ³ bMBg;bt;EbnEdlsþúkEs

epiphysis : 1. Pineal organ, an outgrowth of the roof of the eGBIPIs ³ 1- srIragÁragekanEdllUtlas;ecjBIxagelIxYrcenøaH. diencephalon. 2. Accessory center of ossification at the ends of the 2- mCÄmNÐlkMNq¥wgbnÞab;bnSMénk,alq¥wgEvgrbs; fnikstV bkSI long bones of mammals, birds, and niglµÚnmanRskaxøH. enAeBlkMNq¥wgéntYq¥wgnigeGBIPIsCYbKña karlUt some squamates. When the ossifications of the shaft RbEvgéntYq¥wgk¾Qb;. (diaphysis) and epiphysis meet, further growth in length of the shaft stops. epiphyte : A plant that is supported by the branches of a tree eGBIPIt ³ rukçCatiduHenAelIEmkeQIb:uEnþTajyksMeNImnigGaharBI but derives moisture and nutrients from the air. xül;. episome : A circular genetic element in bacterial cells that can eGBIsUm ³ FatuesenTicragmUlkñúgekasika)ak;etrI EdlGac replicate independently of the bacterial chromosome or integrate sV½ytMelIgeTVedayÉkraCüBIRkUmU:sUm)ak;etrI b¤bBa©ÚlnigsV½ytMelIgeTV and replicate as part of the CaEpñkmYyénRkUmU:sUm)ak;etrI. chromosome. epistasis : A type of interaction between genes such that one gene eGBIsþasIu ³ RbePTénGnþrGMeBIrvagEsn dUcCaEsnmYy bg¥ak;kar interferes with the expression of another gene. For example, in sMEdgecjrbs;EsnmYyeTot. ]TahrN¾ cMeBaHRdUsUPIlEsnGn;kMnt; Drosophila , the recessive gene EPñkxVak; Tb;karsmEdgecjEsnkMnt;BN’EPñkenAeBlCaGUmU:suIkUt. eyeless , when homozygous, prevents the expression of eye color genes. epithelial tissue : A specialized group of cells covering exterior CalikaeGBIetlüÚm ³ RkumekasikaÉkeTsEdlRKbdNþb;épÞxagkñúg and interior body surfaces. nigxageRkAénsarBagÁkay. epitope : The part of a macromolecule or cell that causes eGBItUb ³ Epñkrbs;ma:RkUmU:elKul b¤ekasikaEdlbNþaleGaymankar an antibody response. A complex molecule or cell can contain eqøIytbBIGg;TIk. kMpøicm:UelKulb¤ekasikaGacmantMbn;dUcenHy:ageRcIn. several such sites. epoch : A subdivision of geologic time. CMnan; b¤ sm½ykal ³ karEbgEcklMGiténFrNIkal. epoxide : Three-membered, oxygen-containing ring. eGb:uksIut ³ siucbIRCúgEdlmanGuksIuEsn. equatorial plate : See metaphase metaphase plate plate. pøakeGkVaT½r ³ emIl . equilibrium (chemical) : Condition in which the rate of a lMnwgKImI ³ l½kçx½NÐEdlel,ÓnRbtikmµKImIeTAnigmkmantMélesµIKña. chemical reaction is the same in the forward and reverse directions. kMhab;sarFatuenAxagsþaMnigxageqVgkMresIµKñakñúgsßanPaBlMnwg. Concentrations of substances on the right and left are seldom equal at equilibrium. equilibrium : A state where the rate of particles entering and lMnwg ³ sPaBEdlGRtapg;cUlnigecjesµIKña. leaving a system is equal. equilibrium constant : ³ efrCak;lak;EdlGackMnt;Tis]tþmPaBénRbtikmµ. Mathematical constant K eq that efrlMnwg enables the prediction of the main direction of a reaction.

equilibrium equation : Mathematical expression relating smIkarlMnwg ³ kenSamBiCKNitTak;TgeTAnwgkMhab;GgÁFatuRbtikr concentrations of reactants and products at equilibrium for a given nigGgÁFatukekItenAsßanPaBlMnwgrbs;RbtikmµmYy. reaction. See equilibrium emIl equilibrium constant . constant. era : A large division of geologic time composed of one or more s½k ³ cMEnkd¾FMénFrNIkalEdlrYmmanmYyry³kalb¤eRcInry³kal. periods. erosion : The wearing away of soil by wind, ice, water, and gravity. sMNwk/cMeraH ³ karswkéndIedayxül; Twkkk Twk nigTMnajEpndI. erythrocyte : A red blood cell (containing haemoglobin) that eKalikaRkhm ³ eKalikaQamRkhm ¬maneGm:UkøÚb‘Ín ¦ EdldwknaM transports oxygen throughout the body. They are disc shaped and do GuksIuEsnBaseBjsarBagÁkay . vamanragdUcfas nigKµanéNVyU:eT. not have nuclei. Escherichia coli (E. coli) : A bacterium common in the human eGesrIsüakUlI ¬GIuxUéL ¦ ³ RbePT)ak;etrImüa:g EdlsMbUrenAkñúg gut which has been used a lot in biochemical and genetic research. bMBg;rMlayGaharmnusS EdlRtUv)aneRbIy:ageRcInenAkñúgkarRsavRCav KImICIv³ nigkñúgkarRsavRCavesenTic. esophagus : A tube that connects 322 the pharynx and stomach. See bMBg;Gahar ³ bMBg;EdlP¢ab;edImk nigRkBH. emIlTMBr½ . p.322. essential amino acids : Those amino acids that cannot be GasIutGamIensMxan;² ³ GasIutGamIenEdlsarBagÁkaymnusSminGac synthesized by the human body and must be part of the diet (e.g., sMeyaK)an nigmanEtkñúgGahar. ]TahrN_³ lIsuIn RTIbtUhVan lysine, tryptophan, and valine). nigva:lIn. essential fatty acid : The fatty acid linoleic acid. It cannot be GasIutxøaj;sMxan; ³ GasIutxøaj; GasIutlINUelGIuc EdlsarBagÁkay synthesized, by the human body and must be part of the diet. mnusSminGacsMeyaK)an nigmanEtenAkñgGahar. ester : Functional group derived from an acid and an alcohol. eGEsÞ ³ Rkúmnuxgar)anmkBIGasIutnigGal;kul. estivation (aestivation) : Form of torpor, usually a response to high CIvitRkaMg ³ TMrg;BYnsMgMeqøIytbeTAnwgsItuNðPaBx

ethologist : A person who studies the behavior of animals in natural Gakb,kiriyaviTU ³ GñksikSaBIGakb,kiriyarbs;stVenAkñúgFmµCati. settings. ethology : The scientific study of the nature of behavior and its Gakb,kiriyaviTüa ³ viTüasaRsþsikSaBIlkçN³FmµCatiénGakb,kiriya ecological and evolutionary significance in its natural setting. nigBIsar³sMxan;eGkULÚsIu nigTisvivtþn_rbs;vaenAkñúgFmµCati. ethylene : A compound with the ³ smasFatuEdlmanrUbmnþ C2H4 EdlGacRtUv)anplittam formula C 2H4 that can be produced eGTIELn seasonally by plants and causes leaf abscission. rdUvedayrukçCati nigeFVIeGaysøwkeQIRCuH. etiolation : The abnormal elongation of stems caused by karlUtkñúgmøb; ³ karlUtEvgxusBIFmµtarbs;edImEdlbNþalmkBIkgVH insufficient light; etiolated stems usually lack chlorophyll. Bnøw ¬BnøWminRKb;Rkan; ¦. edImEdllUtxusBIFmµtaenaH eRcInEtxVHkør:UPIl. eubacteria : The majority of all bacteria; their cell walls contain GW)ak;etrI³ )ak;etrIPaKeRcInén)ak;etrITaMgGs;. Pñasrbs;vapÞúkGasuIt muramic acid, certain lipids, and other features that distinguish them muyr:amIk lIBIt niglkçN³BiessepSg²eTotEdleFVIeGayBYkvaxus from archaebacteria. See p. 312. BIGaek)ak;etrI. emIlTMBr½ 312 . eucaryote see GWkarIy:Ut ³ emIl eukaryote . euchromatin : Chromosomal regions that stain lightly and are GWRkUma:TIn ³ tMbn;rbs;RkUmU:sUmEdlcab;BN’Rsal nigrlaEpñkxøH partly uncoiled during the interphase part of the cell cycle and kñúgry³eBlcenøaHvKÁénvdþekasika nigminGacemIleXIjedayRsYl are not easily visible by light edaymIRkUTsSn_eRbIBnøWeT. tMbn;RkUmU:sUmenHRtUv)aneKKitfa manpÞúkEsn microscopy. The region of the chromosomes thought to contain TMrg;PaKeRcIn. most of the structural genes. eugenics laws : Laws designed to eliminate “bad” genes from the c,ab;GWEsnic ³ c,ab;begáIteLIgedIm,Ilb;bM)at;ecalnUvEsn{GaRkk; } human gene pool and encourage “good” gene combinations. BIEsnkñúgxøÜnmnusS nigCYyeGaymanbnSMEsn{l¥ }. euglenoid movement : A type of locomotion in which a euglena clnaGWEKøn ³ RbePTbMlas;TIrbs;GWEKønNa edayrlas;KMrb moves by flexing its pellicle. sarBagÁkayrbs;va. eukaryote or eucaryote : One of the two major types of cells; GWkarIy:Ut ³ ekasikamYyRbePTkñúgcMenamekasikasMxan;BIrRbePT Edl characterized by cells that have a membrane-bound nucleus, as in sMKal;edayekasikaEdlmanPñasB½T§CMuvijéNVy:U dUcCaekasikarukçCati plants, fungi, protists, and animals. pSit RbUTIsþ nigstVCaedIm. emIlTMBr½ 312 . See p. 312. euploid : Polyploid with a n chromosome number that is an GWbøÚGuIt ³ bU:lIbøÚGuItEdlmancMnYnRkUmU:sUmekIneLIgtamBhuKuNén . exact multiple of a basic chromosome set. euryhaline : Capable of living in a wide range of salinities. See also rs;kñúgTwkéRbBit ³ EdlGacrs;enAkñúgTwkéRb)anRKb;kMrit. stenohaline . emIl Stenohaline . euryphagous : Eating a wide range of food items; a food sBVasI ³ EdlsIuGaharRKb;RbePT rWEdlsIuGaharminerIs. generalist. See also stenophagous . emIl stenophagous . eurythermal : Capable of tolerating a wide range of tem- GWrIETm:al ³ E;dlmanlT§iPaBbnSaMueTAnwgsItuNðPaBRKb;kMrit. peratures. See also stenothermal . emIl stenothermal .

eurytopy : Capable of living in a broad range of habitats. yUrIfbPI ³ lT§iPaBrs;enAeRcInkEnøgelIEpndI. eustachian tube : A canal that connects the middle ear cavity RbemayGWsþas ³ bMBg;EdlP¢ab;RbehagRtecokkNþalenAxag behind the tympanic membrane to the pharynx. eRkayRkdasRtecokeTAedImk. evergreen : See non-deciduous. BN’ébtgrhUt ³ emIl non-deciduous . evolution : The theories concerning the processes of vivtþn_ ³ RTwsþIGMBIdMeNIrERbRbYlCIvsaRsþnigsrIragÁrbs;Pavrs; dUcCa biological and organic change in organisms such that descendents Éktþ³CMnan;eRkayxusBIbuBVrbs;va. differ from their ancestors. See emIl Darwinism, Lamarkism, punctuated equilibrium . Darwinism, Lamarkism, punctuated equilibrium. excision repair : Repair of DNA ADN lesions by removal of a karCYsCuledaykat;ecj ³ CakarCYsCul EdlxUc edaykar polynucleotide segment and its replacement with a newly kat;ykGgát;bU:lInuyekøGUTItecj nigkardak;CMnYsedaykarsMeyaKfµI synthesized, corrected segment. EdlCaGgát;RtwmRtUv. excretion : The process of eliminating waste products from a karbeBa©jecal ³ dMenIrbeBa©jecalkaksMNl;BIekasika rWBI cell or living organism. sarBagÁkaymanCIvit. exergonic ( exothermic) (adj) : A reaction that releases energy and beBa©jfamBl ³ RbtikmµEdlbeBa©jfamBl nigekIteLIgeday occurs spontaneously. ÉkÉg. exine : The outermost layer of a spore or pollen grain. The exine GicsuIn ³ RsTab;eRkAbMputrbs;RKab;s,: b¤RKab;lMGg. GicsuInbgáeLIg consists of a resistant polymer that protects the male gametophyte edayb:UlIEmrminRCabTwkEdlkarBarkaEm:tUPIteQµalmineGays¶Üt. from drying out exocarp : The outermost layer (usually the skin) of simple fleshy GicsUkab ¬sMbk ¦ ³ RsTab;eRkAbg¥s; ¬EdleRcInEtCasMbk ¦ rbs;Epø fruits. mansac;eRcIn. exocrine glands : Glands that secrete through ducts to the surface RkeBjbeBa©jeRkA b¤RkeBjGicsURKIn ³ RkeBjEdlmanbMBg; of the body or into hollow organs of the body. beBa©jsarFaturaveTAeRkAsarBagÁkayb¤eTAkñúgsrIragÁRbehagrbs; sarBagÁkay. exocytosis : The transport of material out of a cell by means of GicsUsIutUs ³ kardwknaMsarFatuecjBIekasikaedayfg;sIutU)aøs. vesicles. exogenote : In merozygotes, the segment of the bacterial GicsUEsNUt ³ kñúgemrU:sIukUt CaGgát;RkUm:UsUm)ak;etrIEdlTTYl)anBI chromosome contributed by the donor cell. ekasikaGñkpþl;. exon (extron) : The DNA ADN segments of a gene that are Gicsug ¬GicRtug¦ ³ Ggát; rbs;EsnmYyEdlRtUv)ancMlgRkm transcribed and translated into protein. nigbkERbRkmeTACaRbUetGuIn. exon-shuffling hypothesis : An explanation for how complex new smµtikmµGicsugbnSMfµI ³ karbkRsayBnül;BIrebobEdlEsnfµI genes arise from the joining of independent exons into new saMjaMuelcecjeLIgBIkarP¢ab;énGicsugÉkraCüeTAkñúgbnSMfµI. combinations.

exonuclease : An enzyme that breaks down nucleic acid GicsUnuyekøGas ³ Gg;suImEdlkat;m:UelKulGasuItnuyekøGuiceday molecules by breaking the / / phosphodiester bonds at the 3’ or pþac;sm<½n§pUsVr½DIeGEsÞRtg;cugbBa©b;nuyekøGUTIt #b¤ %. 5’ terminal nucleotides. exoskeleton : An external supportive covering or skeleton. It eRKagq¥wgxageRkA ³ eRKagq¥wgxageRkAEdlRTRTg;sarBagÁkay. is a system of external levers and joints that permits pairs of muscles ]TahrN¾³ sMbkkþam bgág KWCaeRKagq¥wgxageRkA. vaCaRbB½n§Xñas; to act against, or antagonize, each nigsnøak;xageRkAEdlGaceGayKUsac;dMu manGMeBIRbqaMgKña rWGMeBIpÞúyKña other. The exoskeleton is also protective. eTAvijeTAmk. eRKagq¥wgeRkAenHk¾manmuxgarkarBarpgEdr. exothermic (adj) : Chemical reaction that gives off energy. beBa©jfamBl ³ RbtikmµKImIEdlbeBa©jfamBl. experiment : A procedure carried out under controlled conditions in BiesaFn_ ³ viFIsakl,gsmµtikmµenAeRkaml½kçx½NÐRtYtBinitü. order to test a hypothesis. experimental control : see control group control group. emIl . experimental variable : The one factor in an experiment that is GefrBiesaFn_ ³ ktþamYyenAkñúgBiesaFn_EdlxusBIktþaRtYtBinitü. different from the control. expiration : The phase of breathing during which air is degðImecj ³dMNak;kalénkardkdegðImEdlxül;RtUv)anbeBa©jBIsYt. expelled from the lungs. exponential growth phase : A period of time during population vKÁkMenInGics,:ÚNg;Esül ³ry³eBlénkarlUtlas;rbs;b:YBuyLasüúg growth when the population increases at an accelerating rate. enAeBlEdlb:UBuyLasüúgekIneLIgkñúgel,ÓnmYyelOn. expression vector : Plasmids or phage carrying promoter regions viucT½rsMEdgecj ³ )øasµItb¤pasmantMbn;RbUm:UTr½ EdlerobcMedIm,Ibgá designed to cause expression of ADN cloned DNA sequences. eGaymankarsMEdgecjnUvtMnlMdab; køÚn. expressivity : The amount that a phenotype for a given trait is brimaNsMEdgecj ³ brimaNEdlepNUTIbsMrab;kMnt;lkçN³mYy revealed. RtUv)ansMEdgecj. extensin : A family of related glycoproteins that are structural Gicsþg;sIun ³ GMbUrKøIkURbUetGIun EdlCaRbUetGuInTMrg;enAkñúgPñaseRKag. proteins in cell walls. external parasite : A parasite that lives on the outside of its host. brasitxageRkA ³ brasitEdlrs;enAxageRkAFµÜlrbs;va. ]- écEqá external respiration : The exchange of gases between the degðImeRkA ³ bNþÚr]sµ½nrvagmCÄdæanxageRkAnigQam. atmosphere and the blood. exteroceptor : A sense organ near the skin or mucous membrane that FµÜlxageRkA ³ srIragÁviBaØaNénEs,k rWPñasesImEdlTTYlrMejacBI receives stimuli from the external world. xageRkA. extinction : The disappearance of a species from Earth. karvinas ³ kar)at;bg;énRbePTBIEpndI. extranuclear inheritance : Transmission of traits by genetic tMNBUCeRkAéNVy:U ³ karbB©aÚnlkçN³edayBt’manesenTicmanenA information contained in cytoplasmic organelles such as kñúgFatuekasikaénsuItU)aøs dUcCamItUskugRDI nigkør:U)aøs. mitochondria and chloroplasts.

extraperitorical : Positioned in the body wall beneath the lining of the eRkAPñaseBaH ³ EdlmanTItaMgkñúgsarBagÁkayCab;nwgPñaseBaH coelom (the peritoneum) in contrast to being suspended in the EdlpÞúyeTAnwgTItaMgBüÜrkñúgsWLúÚm Tb;RTedayPñaseBaHevon. coelom by mesenteries. extrinsic factors : Population- controlling factors that arise ktþaBIxageRkA ³ ktþaRtYtBinitüb:UBuyLasüúgEdlekIteLIgb¤elceLIg outside the population. xageRkAb:UBuyLasüúgenaH. eye : The light receptor organ of sclera, cornea, choroid, animals. See sclera, cornea, EPñk ³ srIragÁTTYlBnøWrbs;stV . sUmemIl choroid, ciliary body, ciliary ciliary body, ciliary muscle, iris, retina, aqueous humour, muscle, iris, retina, aqueous accommodation, vitreous humour, rod cells, cone cells, fovea centralis, humour, accommodation, optic nerve, blind spot, colour blindness, binocular vision, conjunctiva, vitreous humour, rod cells, cone lens, pupil cells, fovea centralis, optic nerve, . blind spot, colour blindness, binocular vision, conjunctiva, lens, pupil. eye, compound : A type of light receptor found in insects and EPñksmas rWEPñkEkveRcIn ³ RbePTFøÜlBnøWRbTHeXIjcMeBaHstVl¥it crustaceans, that is made of many ommatidia which each form a nigBYkRKusþaes EdlbgáeLIgedayÉktaEPñkCaeRcIn kñúgenaHÉktanImYy² separate image. begáItrUbPaBepSg²Kña. eyepiece : The lens in a compound microscope that magnifies the EkvBRgIkEk,rEPñk ³ EkvBRgIkenAkñúgmIRkUTsSn_smas EdlBRgIk image produced by the objective lens; the ocular. rUbPaB)anmkBIEkvBRgIkGubsicTIb. rWk¾RtUv)anehApgEdrfaGUKuyEl. eyespot : A small pigmented area sensitive to light, present in sñamEPñk ³ tMbn;CatiBN’tUcmYyEdlrYseTAnwgBnøWénstVÉkekasika unicellular organisms, green algae, zoospores and some gametes. sarayébtg sUs,: nigkaEm:tmYycMnYn. F F- cell : A bacterial cell that does F - (F) not contain a fertility (F) factor. ekasika ³ ekasika)ak;etrIEdlKµanpÞúknUvktþabnþBUC . vaedIrtYCa Acts as a recipient in bacterial conjugation. GñkTTYlkñúgCMnab;bþÚr)ak;etrI. F’ factor : A fertility (F) factor F’ ( F ) that contains a portion of the ktþa ³ ktþabnþBUC EdlmanenAkñúgEpñkmYyrbs;RkUmU:sUm)ak;etrI. bacterial chromosome. F factor : An episome in bacterial F cells that gives them the ability to ktþa ³ egBIsUménekasika)ak;etrIEdleFVIeGayekasikaenaHman act as a donor in conjugation. lT§PaBedIrtYCaGñkpþl;eGaykñúgeBlCMnab;bþÚr. F pilus : See pilus. emIl pilus . F+ cell : A bacterial cell having a F+ (F) fertility (F) factor. Acts as a donor ekasika ³ Caekasika)ak;etrIEdlmanktþabnþBUC . va in bacterial conjugation. edIrtYCaGñkpþl;eGaykñúgeBlCMnab;bþÚr)ak;etrI. F1 generation : The first F1 : generation of offspring in a genetic CMnan; CMnan;kUnTImYyénkarbgáat;esenTic. cross. F2 generation : The second F2 : generation of offspring in a genetic CMnan; CMnan;kUnTIBIrénkarbgát;esenTic. cross.

facilitated diffusion : Transport of substances across the membrane of sMNaygay ³ kardwkCBa¢ÚnsarFatuqøgkat;Pñasekasika Edlkñúg a cell in which proteins speed up the movement. The substances can enaHRbÚetGIunbegáInel,Ónclna. sarFatuGacqøgkat;BIkMhab;xøaMgeTA only flow down their gradient. kMhab;exSay. facultative : (of an organism) Capable of living in unusual paKultaTIv ³ ¬cMeBaHPavrs; ¦ Gacrs;enAkñúgl½kçx½NÐminFmµta)an. conditions. facultative anaerobe : Anaerobic bacteria that usually grows Kµanxül;BuMcaM)ac; ³ )ak;etrIminRtUvkarxül; EdlCaTUeTAlUtlas;eday aerobically but has adjusted to live without oxygen under aerobic and RtUvkarxül ;b:uEnþvasMrbeTAnwgCIvitKµanGuksIuEsnkñúglkç½x½NÐmanxül; anaerobic conditions. nigKµanxül;. facultative heterochromatin : Chromatin that may alternate in eGetr:URkUm:aTIn paKultaTIv ³ RkUma:TInEdlGacmanTMrg;qøas;Kña form between euchromatic and Y heterochromatic. The Y rvagGWRkUma:TicnigeGetrU:RkUma:Tic. RkUmU:sUm énRbePTCaeRcInpÞúk chromosome of many species eGetr:URkUm:aTInpaKultaTIv. contains facultative heterochromatin. FAD (flavin adenine FAD dinucleotide) : A hydrogen carrier ³ GñkdwknaMGIuRdUEsneRbIR)as;kñúgdegðIm. used in respiration. faeces, feces : The waste material eliminated by the gastrointestinal lamk ³ sarFatusMNl;EdlbeBa©jedaycugeBaHevon. tract. Fahrenheit scale : Temperature scale used in the United States in RkithVarinéh ³ RkitsItuNðPaBEdleKeRbIenAshrdæGaemrik 0 which water freezes at 32 F and 32 0F 212 0F 331 boils at 212 0F. See p.331 EdlTwk kkenA nigBuHenA . emIlTMBr½ . familial trait : A trait transmitted through and expressed by members lkçN³tMNvgS ³ lkçN³Edlem)abBa©ÚnmksnþaneRkay nig of a family. sMEdgeLIgkñúgsmaCikénRKYsarmYy. family : A group of related taxonomic genera. GMbUr ³ RkuménBYkEdlmanTMnak;TMngKñakñúgrebobcMENkfñak;. fascicle : A cluster of pine leaves (needles) or other needlelike leaves kBa©Músøwk ³ cegáamsøwkRsl; ¬ragm¢úl¦ b¤søwkdUcm¢úld¾éTeTotrbs; of gymnosperms. rukçCatisuImNUEs

feces : See faeces. lamk ³ emIl faeces . feedback inhibition : Control mechanism in which the increasing karbg¥ak;;Rtlb; ³ clnkarRtYtBinitüEdlkMenInkMhab;rbs;m:UelKul concentration of a molecule inhibits the further synthesis of that mYy bg¥ak;karsMeyaKm:UelKulenaHteTAeTot. molecule. femur : The upper bone in the hind limb of tetrapods. See pentadactyl q¥wgePøA ³ q¥wgelIénGvyv³eRkayrbs;stVeCIgbYn. limb, and p.321. sUmemIl pentadactyl limb nigemIlTMBr½321 . fermentation : An anaerobic process whereby organic el,Ig ³ dMenIrKµanxül; EdlsmasFatusrIragÁdUcCakabUGIuRdatRtUv)an compounds such as carbohydrates are broken down to form products bMEbkeGayeTACaplitplepSgdUcCaGasIutLak;Tic b¤Gal;kul. such as lactic acid or alcohol. fertility (F) factor : See F factor. ktþabnþBUC ³ emIl F factor . fertilization : The union of two gametes to form a zygote. karbgákMenIt ³ karrlaycUlKñaénkaEm:tBIredIm,IbegáItCasIukUt. fetus, foetus : A human embryo in its later stages of development KP’ ³ GMRb‘Íy:ugmnusSenAdMNak;kalcugeRkayénkarlUtlas;rbs;va. usually after the formation of the amnion which is about 8 weeks CaTUeTAvaekIteLIgbnÞab;BIkarkekItfg;TwkePøaH Edlmanry³eBlRbEhl after conception. CaR)aMbIs)aþh_ bnÞab;BIkarbgákMeNIt. fiber, fibre : 1. Indigestible carbohydrates of the human diet; 111-1 srés ³ kabUGIuRdatminGacrMlay)an EdlmankñúgcMNIGahar mostly polysaccharides, such as cellulose, and complexes of mnusS ehIyPaKeRcInCab:UlIsakarItdUcCaEsluyLÚsnigkMpøicén polysaccharides. 2. A strand of b:UlIsak;karIt. 2- PIb ³ rbMuFatuRbÚtU)øasEdlplitrWbeBa©jeday protoplasmic material produced or secreted by a cell and lying outside ekasika nigsßitenAxageRkAekasika rW Caekasikaekør:gsuImEvg²manPñas the cell, or an elongated, thick-walled sclerenchyma cell; Rkas;. vaCYyRTRTg;nigkarBarrukçCati. helps support or protect the plant a fiber-like cell. fibril : A small fibre produced by a cell and lying within the cell. kUnPIb ³ sréstUcEdlplitedayekasika nigsßitenAkñúgekasika. fibrous proteins : Fiber-like proteins that are usually insoluble. RbÚetGIunsrés ³ RbÚetGIunmanTMrg;CasrésEdlCaTUeTAminrlay. fibula : One of the two bones in the lower hind limb of tetrapods; q¥wgtUckMPYneCIg ³ q¥wgmYykñúgcMeNamq¥wgBIrenAkñúgGvyv³eRkayrbs; parallel to the tibia. See pentadactyl limb, and p. 321. stVeCIgbYn nigsßitenARsbeTAnwgq¥wgsµgeCIg. sUmemIl pentadactyl limb nigTMBr½ 321 . fiddlehead : A new, tightly coiled fern frond. kUnbNÑgÁCati ³ FagbNÑgÁCatiEdleTIbEtduHfµImUry:agENn. field capacity : The water-storage capacity of soil; the amount of smtßPaBdI ³ lT§PaBrkSaTwkTukrbs;dI. brimaNTwkkñúgdI water in soil after gravitational percolation stops. bnÞab;BIkarhUreRcaHeTAkñúgdIQb;. filament : A slender stalk that supports the anther; a group of PILam:g; rWTgeksreQµal ³ kUnTgEdlRTRTg;e)aøklMGg. cells joined end to end as in certain algae. RkumekasikaEdltP¢ab;KñadUcCacMeBaHsaraymYycMnYn.

filial : Refers to one generation of offspring; the first set of offspring CMnan;kUn ³ sMedAeTAelIkUnmYyCMnan;. RkumkUnTImYyEdl)anmk from a hybridization experiment is BIBiesaFn¾bgáat; KWCaCMnan;kUnTImYy (F 1) ehIyRkumTIBIr KWCaCMnan;kUnTIBIr the first filial generation (F 1), the second set is the second filial (F 2).l. generation (F 2), etc. filial generations : See F1, F2 F1 , F2 generation generations. CMnan;kUn ³ emIl . filiform : Like a thread. TMrg;srés ³ ragdUcsrésGMe)aH. filter feeders : Animals that use cilia or other appendages to create stVsIuGaharedayeRcaH ³ stVEdleRbIeramj½r b¤ExñgepSg² water currents and filter food out of the water. eTotedIm,IbegáItcrnþTwk niigeRcaHykGaharBITwkenaH. filtration : Process that separates large molecules from small ones by cMeraH ³ dMeNIrEjkm:UelKulFMecjBIm:UelKultUcedaykarEjkecjBIKña. exclusion. Small molecules pass through pores, but large molecules m:UelKultUc²qøgkat;rn§)an b:uEnþm:UelKulFM²nigPaKli¥tRtÚv)anrkSaTuk and particles are retained. ¬minGacqøgkat;tamrn§)an ¦. fingerprint : 1. The pattern of ridges and whorls on the tip of a 1- sñamRmaméd ³ KMrUéncg¥Úr nigRkeyAédenAelIcugRmaméd. finger. 2. The pattern obtained by two-dimensional chromatography 2- hVIúghÁ½rRBIn ³ KMrUTTYl)anedayRkUma:tURkabPIvimaRtBIrb¤GKÁIsnIviPaK or electrophoresis of a protein or énRbUetGuInb¤GasuItnuyekøGuIcEdlRtUv)ankat;CacMENktUc²edayGg;suIm. nucleic acid that has been broken into smaller fragments by enzymes. first gap : See G1 phase. cenøaHTI1 ³ emIl G1 phase . first ionizing energy : Energy required to remove the first famBlGIuy:ugkmµdMbUg ³ famBlEdlRtÚvkaredIm,IdkykeGLicRtúg electron from a neutral atom. TImYyBIGatUmNWt. First Law of Thermodynamics : Energy in the universe remains c,ab;ETm:UDINamicTI1 ³ famBlenAkñúgsklEdlmanlkçN³efr constant; it can neither be created nor destroyed. Also referred to as Canic© vaminGacRtUv)anbegáIteLIgb¤bMpøajeT. vak_mann½ydUcCac,ab; the Law of Conservation of rkSafamBlEdr. Energy. first-order consumer : See primary consumer primary consumer. emIl . fission : 1. A process in which one 1 2 cell divides in two. 2. The splitting karEck ³ - dMeNIrEdlekasikamYyEckCaBIr. - karpþac;GatUm of atoms to produce energy. edIm,IbegáItfamBl. fitness : A measure of an individual’s evolutionary success; lT§PaBrs; ³ rgVas;énkarTTYleCaKC½ykñúgkarvivtþrbs;Éktþ³mYy. number of its surviving offspring relative to the number of surviving cMnYnkUnrbs;vaEdlmanCIviteFobeTAnwgkUnrbs;;Éktþ³epSgeTotEdlenA offspring of other individual’s rs;enAkñúgb:UBuyLasüúgenaH. within the population. fixation : In , a condition in which all members of CMnab;GaELl ³ cMeBaHesenTicb:UBuyLasüúgCasßanPaBEdlcMnYn a population are homozygous for a given allele. smaCikTaMgGs;rbs;b:UBuyLasüúg CaGUm:UsuIkUtsMrab;GaELlNamYy. flagellum (pl. flagella): A thread-like locomotory organelle pøaEsl ³ FatubMlas;TIdUcsrésGMe)aH EdlbgáeLIgedaykUnbMBg;Ca containing a highly organized array of microtubules; longer than a eRcInEvgCageramj½r nigeRcInmanExñgcMehogCaeRcIneTotpg. cilium and often bearing numerous lateral projections.

flame cell : Ciliated cells that help remove excess water from a ekasikaeramrlk ³ ekasikamaneraméndgáÚvsMEb:tkñúgTwk EdlCYynaM turbellarian flatworm. TwkelIsecjBIkñúgxøÜn. flavin mononucleotide (FMN) : The first electron acceptor in the m:UNUnuyekøGUTItpøavIn ³ GñkTTYleGLicRtugTI1enAkúñgRcv:ak;dwknaM electron transport chain eGLicRtug. flavonoid : Any compound derived from phenylpropanol that is linked pøav:UNUGIut ³ smasFatumanRbPBBIepnIlRbU)a:NulEdlP¢ab;eTAnwg to three acetate units and condensed into a multiple-ringed ÉktaGaestat3 ehIyRtUv)anbgðab;eTACaTMrg;EdlmansiuceRcIn. structure. : 1. The plants or organisms 1- (other than animals) of a particular BBYkrukçCati ³ rukçCati rWPavrs; ¬eRkABIstV ¦EdlduHenAkñúgtMbn;mYy. region. 2. Also, a book about the 2- taxonomy of plants of a particular esovePAGMBIrebobcMENkfñak;rukçCatienAkñúgtMbn;mYy. region. flower : The reproductive structure of angiosperms. páa ³ rcnasm<½n§bnþBUCrbs;Gg;süÚEs

Food Guide Pyramid : A diagram that recommends the daily BIr:amItENnaMBItMrUvkarGahar ³ düaRkamEdlENnaMBIkarbriePaK intake of food from each of the five food groups for good nutrition. We GaharRbcaMéf¶ BIGaharnImYy²kñúgcMeNamGaharTaMgR)aM edIm,ITTYl need most Grains and Cereals, then )anGaharl¥. eyIgRtUvkarPaKeRcInnUvRKab;FBaØCati nigbnÞab;mkRtUvkar less Fruit and Vegetables, less Meat and Eggs, less Milk products ticCagnUvEpøeQI bEnø sac; s‘ut plitpleFVIBITwkedaH nigRtUvkar and least Fats and Sugar. brimaNy:agticbMputnUvxøaj; nigsár. food vacuole : An organelle in some protists that collects and v:aKuyGUlGahar ³ Fatuekasikarbs;RbUTIsþmYycMnYn EdlRbmUl nig digests food. rMlayGahar. food web : A series of interrelated food chains in an ecosystem . bNþajGahar ³ es‘rIRcvak;GaharEdlmanGnþrTMnak;TMngenAkñúgzan RbB½n§. foot : 1. The base of vertebrate legs. 2. A muscular organ used for 1- RbGb;eCIg ³ EpñkxageRkaméneCIgrbs;stVq¥wgkg. locomotion in most mollusks. 3. Base of a moss sporophyte. 2- eCIg ³srIragÁsac;duMEdleRbIsMrab;bMlas;TIénsib,IstVPaKeRcIn. 3- Kl;s,:r:UPItrbs;Esø. footprinting : A technique for ADN identifying a DNA sequence that PUtRBInFIg ³ bec©keTskMNt;tMNlMdab; EdlrMuCab;nwg binds to a particular protein, based ADN- on digestion of the DNA protein RbUetGuInCak;lak;mYy ehIyEp¥keTAelIkarrMlayrbs;kMepøc complex by an endonuclease so RbUetGuIn eday endonuclease dUcecñHmanEttMbn;EdlRtUv)ankarBar that only the area protected by the protein remains unchanged. edayRbUetGIuneT EdlKµankarERbRbYl ¬enAdEdl ¦. foramen magnum : The opening in the skull where the spinal cord rn§llad¾ ³ rn§Rbehagrbs;llad¾k,alsMrab;xYrq¥wgxñgcUleTAP¢ab;xYr enters. k,al. formula : The group of chemical symbols that indicate what rUbmnþ ³ RkumnimitþsBaØaKImIEdlbgðajBIFatuenAkñúgsmasFatunigcMnYn elements are in a compound and the number of each kind of atom GatUmnImYy²énsmasFatu . manrUbmnþBIrRbePTEdlRtUv)aneKeRbIKW present. Two types are used: rUbmnþBiesaFn_nigrUbmnþeRKag. ]TahrN_ ³ smasFatu MgC1 2 empirical and structural. e.g., MgC1 2 has two chloride ions for manGIuy:ugkørBIrsMrab;ral;GIuy:ugma:ej:süÚmmYy. every magnesium ion. formula weight : Sum of the atomic weights of the elements rUbmnþma:s ³ plbUkma:sGatUménFatuTaMgGs;Edlbgá constituting the simplest formula of an ionic compound. CarUbmnþgaybMputrbs;smasFatuGIuy:Unic. formylmethionine (fMet) : A molecule derived from the amino prmIlemtüÚnIn ³ m:UelKul)anmkBIGasuItGamIenemtüÚnIn edayPa¢b; acid methionine by attachment of a formyl group to its terminal amino RkumprmIleTAnwgRkumGamInrbs;va. enHKwCaGasuItGamIenTI1EdlRtUv)an group. This is the first amino acid bB©ÚaleTAkñúgb:UlIbuibTIt)ak;etrITaMgGs;. vak¾RtUv)ansÁal;pgEdrfaCa inserted in all bacterial polypeptides. Also known as N-prmIlemtüÚnIn. N-formyl methionine. fossil : An imprint or remains of an organism that lived long ago, pUsIul ³ sñam rWsMNl;;rbs;Pavrs; EdlmanCivitrs;enAkalBICMnan; preserved in rock. munyUrmkehIy EdlsßitenAkñúgfµ. fossil fuel : Combustible materials that are the remains of ancient, pUsuIlcMehH ³ sarFatuduteqH EdlCasMNl;rbs;stV nigrukçCati fossilized plants and animals. pUsIul.

fossorial : Burrowing through the soil. karCIkrUgkñúgd I founder effect : The effect of establishing a population by a \T§iBlGñkbegáIt ³ \Ti§BlénkarbegáItb:UBuyLasüúgedayÉktþ³mYy small number of individuals whose genotypes carry only a fraction of cMnYntUc EdlesNUTIbrbs;vamanEtGaELlmYyEpñkénRbePTGaELl the different kinds of alleles in the epSg²Kñaénb:UBuyLasüúgedIm. original population. fovea centralis : The area of sharpest vision on the retina, tMbn;pUevGa ³ tMbn;KMehIjc,as;bMputelIerTIn EdlbgáeLIgEteday containing only cones, where light is sharply focused. ekasikaekan nigEdlBnøWRbmUlpþúMeTATIenaH. fragile site : A heritable gap or nonstaining region of a tMbn;RsYy ³ cenøaHEdlGacTTYlmrtk b¤tMbn;minGaccab;BN’én chromosome that can be induced to generate chromosome breaks. RkUm:UsUm1EdlGacnaMeGaygaypþac;RkUm:UsUm. fragmentation : Asexual reproduction in some lower plants karkat;daM ³ karbnþBUCeday\tePT EdlEpñkrbs;rukçCatilUtlas;eTA in which pieces of a plant grow into complete new plants. CarukçCatieBjeljfµI. frameshift mutation : Mutation resulting from insertion or deletion muytasüúgbþÚr ³ muytasüúgEdlbNþalmkBIkarbBa©Úl)as rWkaryk of a base from a DNA strand. The DNA codon at that point plus all that )asecjBIRcvak; . kUdugRtg;cMNucenaH nigkUdugbnþbnÞab;RtÚv)an follow are changed causing the pøas;bþÚr EdleFIVeGaysaresenTicbkERbminRtwmRtUv. genetic message to be translated incorrectly. fraternal twins : The offspring resulting from two eggs being kUnePøaHxusKña rWkUnePøaHminBit ³ kUnEdl)anmkBIkaEm:tjIBIr fertilized by two different sperm. dizygotic twins See dizygotic twins. bgákMeNItCamYyEs

(pl. fungi) : The common Mycetae name for the kingdom Mycetae. pSit ³ eQµaHeRbITUeTAsMrab;rC¢³ . Pavrs;brCIBEdlKµan Heterotrophic organisms lacking 313 chlorophyll. See p. 313. kør:UPIl. emIlTMBr½ . funicle : The stalk of an ovule used to attach to the placenta in TgGUvul ³ Tgrbs;GUvul EdleRbIsMrab;P¢ab;eTAnwgpáarukçCati. plants. furanose : Five-membered ring form of monosaccharides. The ring pYra:NUs ³ TMrg;CasiucR)aMRCúgénm:UNUsakarIt. siucenHdUcCa resembles the cyclic ether furan. siuceGETpYra:n. furcula : In birds, the wishbone formed by the fusion of the two hV½rXüÚl½r ³ cMeBaHbkSI Caq¥wgEdlekIteLIgBIkarrlaycUlKñaénq¥wgdg clavicles at their central ends. kaMbitBIrenARtg;cugrbs;va. fusiform initials : Vertically elongated cells in the vascular ekasikaG½kSdMbUg ³ ekasikaRTEvgbBaÄr² enAkñúgkMbüÚmsrésnaM cambium that produce cells of the axial system in the secondary EdlplitekasikaénRbB½n§G½kS enAkñúgsuIELmTI2nigpøÚEGmTI2. xylem and secondary phloem. G G1 Phase : During interphase, the G part of the cell cycle that occurs vKÁ 1 ³ enAcenøaHvKÁ CaEpñkénvdþekasika Edlcab;epþImeLIgenAcenøaH between the end of mitosis and the ADN G1 beginning of DNA synthesis; G1 cugmItUs nigkarcab;epþImsMeyaK . sMedAelIcenøaHTI1. refers to first gap. G2 Phase : During interphase, the G S portion of the cell cycle that begins vKÁ 2 ³ enAcenøaHvKÁ CaEpñkénvdþekasikaEdlcab;epþImenAcugvKÁ at the end of the S phase and lasts G2 until the beginning of mitosis; G 2 nigbBa©b;enAedImmItUs. sMedAelIcenøaHTI2. refers to the second gap. gall bladder : The organ in which bile is stored. fg;TwkRbmat; ³ srIragÁEdlsþúkTwkRbmat;. gametangium (pl. gametangia ) : gametangia A cell or structure in which GgÁplitkaEm:t ¬Bhu> ¦³ ekasikab¤TMrg;EdlCakEnøg gametes are produced. plitkaEm:t. gamete : A haploid reproductive cell; A mature germ cell, either kaEm:t ³ ekasikabnþBUCGabøÚGIut. ekasikabnþBUCeBjv½y ³ male or female; The sex cells involved in fertilization. jI rWeQµal. ekasikaePTEdlcUlrYmkarbgákMenIt. gametogenesis : The formation of gametes; the meiotic, cell kMNkaEm:t ³ dMeNIrcMENkekasika ¬emy:Us ¦EdlbegáItekasikaePT³ division process that produces sex cells; oogenesis and kMNGUvul nigkMNEs

ganglion : A group of nerve cell bodies outside the brain or spinal kg;KøIy:ug ³ RkumekasikaRbsaTenAxageRkAxYrk,al rWxUrq¥wgxñg. cord. gas : The state of matter in which the atoms or molecules are far from ]sµ½n ³ sßanPaBrbs;sarFatuEdlGatUm rWmU:elKulsßitenAqJayBIKña each other and moving rapidly. Therefore the force of attraction nigeFVIclnay:agrh½s. dUecñ³kMlaMgTMnajrvagGatUm rWmU:elKulTaMgena³ between them is weak. KWexSay. gas vacuole : A membrane-bound bubble of gas that enables aquatic v:aKuyGUl]sµ½n ³ BBuH]sµ½nenAkñúgPñasCit EdlGaceFVIeGay)ak;etrI bacteria to float. kñúgTwkbENþt)an. gastric juice : A fluid in the stomach made of enzymes, water, rsRkBH ³ vtßúravkñúgRkBHbgáeLIgedayGg;sIum Twk nigGasIutkørIRDic. and hydrochloric acid. gastrovascular canals : Fluid-filled canals opening at the bMBg;rMlayGahar ³ bMBg;EdleBjeTAedaysarFaturav ebIkcMh mouth of cnidarians and Cnidarians Ctenophores ctenophores that function in gas enARtg;mat;én nig EdlmanmuxgarbþÚr ]sµ½n exchange and in the distribution of nigEckcaycMNI. nutrients. gastrovascular cavity : The interior space of a coelenterate RbehagrMlayGahar ³ Rbehagxagkñúgrbs;sWLg;eter EdlCakEnøg where digestion occurs. mankarrMlayGahar. gastrula : The stage following the blastula stage during which germ hÁa®sÞÚLa ³ dMNak;bnÞab;BIdMNak;)aøsÞÚLa EdlRsTab;ekasikaxñRtUv layers are formed. )anbegáIteLIg. gastrulation : Creation of a new tissue layer by the movement of hÁaRsÞÚLasüúg ³ karkekItRsTab;CalikafµImYyedayclnaekasika cells in the early embryo (blastula). enAdMNak;kaldMbUgénGMRb‘Íy:ug (Blastula) . Geiger-Muller counter : An Geiger-Muller : instrument that detects and counts naLika Ca]bkrN_sMrab;emIl nigrab; kaMrsµIGal;hVa alpha, beta and gamma radiation by recording the ionised gas particles ebta nighÁamaedaykarkt;RtaPaKl¥itGIuy:ug]sµ½n EdlekIteLIgenAeBl produced as the radiation passes kaMrsµIenaHqøgkat;bMBg;mYyman]sµ½n. through a gas filled tube. gel electrophoresis : A technique by which nucleic acids or proteins eCleGLicRtÚpers ³ bec©keTsmYyEdlGasuItnuyekøGiuc are separated in a gel that is placed in an electric field. b¤RbUetGuInRtUv)anEjkecjBIKñaenAkñúgsarFatuxab;Gn§ilEdldak;kñúgEdn GKÁIsnI. gemma (pl. gemmae) : Asexual liverwort plantlets in some liverworts and esm:a ³ rukçCatitUc EdlbnþBUCeday\tePTén nigEsømYy mosses that can form new gemmae gametophytes; often form in cMnYn EdlGacbegáItkaEm:tUPItfµI)an ehIyeRcInkekItenAkñúg gemmae cups. cups . gemmule : A type of asexual reproductive structure in sponges Es‘mUl ³ RbePTénTMrg;bnþBUCrbs;eGb:ugEdlekItBIRkumekasika made of a tough-walled group of amoebocytes. GamIbmanPñassiVt. gene : A piece of chromosomal DNA DNA that codes for a particular Esn ³ Ggát; énRkÚmU:sUm EdlcMlgRkmsMrab;lkçN³yfaRbePT trait; the basic unit of heredity; the information in a DNA molecule mYy EdlCaÉktaRKwHéndMNBUC. vaCaBt’mankñúgm:UelKul that codes for one polypeptide DNA EdlcMlgsMrab;Rcv:ak;b:UlIbiubTItmYy. chain.

gene amplification : The process by which many copies of some karbegáInEsn ³dMeNIrEdlEsnyfaRbePTmYycMnYnRtUv)anbegáIt specific genes are made at one time, while other genes are not eLIgkúñgeBlEtmYy cMENkÉEsndéTeTotKµansV½ytMelIgeTVeT. replicated. : The change of one allele to another during cMlas;Esn ³ karbþÚrBIGaElsmYyeTAGaEllmYyeTotkñúgkMLúgeBl crossing over. RkUsuIjGUevI. gene duplication : A mutation during replication leading to the karekIneTVEsn ³ muytasüúgekItkñúgry³eBlsV½ytMelIgeTVEdl production of two copies of a gene sequence. naMeGaymankarbegáIttMnlMdab;EsnBIr. gene flow : The movement of genes from, one generation to lMhUrEsn ³ clnarWkarbBa¢ÚnEsnBICMnan;mYyeTACMnan;mYy b¤BIkEnøg another or from one place to another or between two mYyeTAkEnøgmYyeTot b¤rvagb:UBuyLasüúgBIrEdlbNþalmkBIkarsay populations, brought about by the PayénkaEm:t b¤karpøas;TIrbs;Éktþ³. spread of gametes or the migration of individuals. gene frequency : The proportion of a particular allele in a eRbkg;Esn ³ smamaRtrbs;GaELlNamYykñúgb:UBuyLasüúg. population. gene gun : An instrument that ADN shoots tiny beads coated with DNA ]bkrN_bBa¢ÚnEsn ³ ]bkrN¾eRbIsMrab;)aj;RKab;tUc²eRsab directly into cells; some cells treated this way integrate the edaypÞal;cUleTAkñúgekasika. ekasikamYycMnYnRtUv)aneKeFVItam viFIenH foreign DNA that is shot into them, edIm,IbBa©Úl ADN BIxageRkAcUleTAkñúgekasikaenaH ehIyk¾)ankøayCa thereby becoming transgenic. ekasikaEdlmanbnSMEsn. gene interaction : Production of new phenotypes by the interaction GnþrGMeBIEsn ³ karbegáItepNUTIbfµI²edayGnþrGMeBIGaELlénEsn of alleles of different genes. epSg². gene mutation : See point point mutation mutation. Esnmuytasüúg ³ emIl . gene pool : All the genes present in a population. CRgukEsn ³ EsnTaMgGs;EdlmanenAkñúgb:UBuyLasüúg. generalized transduction : The transduction of any gene in the kardwkCBa¢ÚnEsn ³ kardwkCBa¢ÚnEsnNamYyeTAkñúgesNUm)ak;etrI bacterial genome by a phage. edaypas. generation time : The length of time it takes an organism from Gayukalv½y ³ ry³eBlEdlKitcab;taMgBIekItrhUtdl;eBjv½yrbs; birth to reach sexual maturity. Pavrs;mYy. generative cell : The cell in the pollen grains of angiosperms that ekasikabgákMenIt ³ ekasikaenAkñúgRKab;lMGgénGg;süÚEs

generative processes : Actions that increase the size of an dMeNIrkMeNIn ³ GMeBIeFIVeGayekInTMhM ¬FMFat; ¦énPavrs; b¤ekIncMnYn individual organism (growth) or increase the number of individuals Éktþ³b:UBuyLasüúg ¬karbnþBUC ¦. in a population (reproduction). gene-regulator proteins : Chemical messengers within a cell RbÚetGIuntMrUvEsn ³ GñknaMsarKImIenAkñúgekasikaEdlpþl;Bt’maneTA that inform the genes as to whether protein-producing genes should be EsnfaetIEsnEdlsMeyaKRbUetGuInRtUvebIkb¤biT b¤faetIEsnTaMgenaH turned on or off, or whether they RtUvbegáInb¤bnßyskmµPaBplitRbUetGIun. ] ³gene –repressor proteins should have their protein producing activities increased or decreased. KWCaRbUetGIuntMrUvEsnEdlbnßykarplitRbUetGIun cMENkÉEsn gene- eg, gene-repressor proteins and gene-activator proteins. activator proteins KWCaRbUetGIuntMrUvEdlbegáInnUvkarplitRbUetGIun. genetic burden : Average number of recessive lethal genes carried in bnÞúkesenTic ³ cMnYnmFüménEsnGn;bgásøab;EdlRtUv)anbBa©Únkñúg the heterozygous condition by an individual in a population. Also lkçx½NÐeGetrU:suIkUtedayÉktþ³mYyenAkúñgb:UBuyLasüúg. vak¾RtUv)aneK called genetic load. ehApgEdrfa genetic load . genetic code : The nucleotide triplets (codons) that code for the RkmesenTic ³ nuyekøGUTIt3 ¬kUdug ¦ EdlcMlgRkmsMrab;GasuIt- 20 amino acids or for chain 317 initiation or termination. See p.317. GamIenTaMg20 b¤sMrab;karcab;epþIm; b¤karbBa©bRcvak;. emIlTMBr½ . genetic counselor : A professional with specific training TIRbwkSaesenTic ³ GñkCMnajEdl)aneronBIesenTicmnusS nigGac in human genetics who can advise on the likelihood of genetic defects pþl;eyabl;BIlT§PaBénkarbBa¢ÚnvibtiþesenTiceTAeGaykUn. being passed to children. genetic distance : Measure of the amount of genetic difference KMlatesenTic ³ rgVas;brimaNxusKñaénesenTic rvagb:UBuyLasüúg between different populations or species. b¤RbePTepSg²Kña. : the a mount of variety of allele in a population esenTiccMruH ³ cMnYnRbePTGaELlnanaenAkñúgb:UBuyLasüúgmYy. genetic drift : A random variation in gene frequency in a small sMNat;esenTic ³ bMErbMrYledayécdnürbs;eRbkg;Esn kñúg population. b:UBuyLasüúgtUcmYy. : The use of ADN recombinant DNA and cloning visVkmµesenTic ³ kareRbIbec©keTs bnSMeLIgvij nigbec©keTs techniques to produce new genes, biological products, or organisms eFIVkøÚnedIm,IbegáItEsnfµI. plitplCIvsaRsþ rWPavrs;EdlmanlT§PaBeFIV with permanently altered abilities. eGaymankarpøas;bþÚrCaRbcaM. genetic equilibrium : A state achieved in a population when lMnwgesenTic ³ sPaBsMerc)anenAkñúgb:UBuyLasüúgenAeBlEdl there is no change in gene frequency over a period of time. eRbkg;Esnminpøas;bþÚrkñúgmYyry³eBlNamYyenaH. genetic fine structure : Analysis of recombination within genes that rcnasm<½n§esenTic ³ karviPaKBIkarbnSMeLIgkñúgEsn Edlpþl;bøg; provides mapping information at the level of individual nucleotides. Bt’manesenTicenARtg;kMriténnuyekøGUTIteTalmYy. genetic isolating mechanism : reproductive isolation See reproductive isolation. clnkarpþac;esenTic ³ emIl . genetic load : See genetic burden. bnÞúkesenTic ³ emIl genetic burden .

genetic polymorphism : When two or more discontinuous BhusNæanesenTic ³ enAeBlEdlesNUTIbminbnþCab;KñaBIrb¤eRcIn genotypes coexist in a population, produced by different alleles of the elceLIgdUcKñakñuúgb:UBuyLasüúgmYy RtUv)anplitedayGaELlxusKñaén same gene. When the frequencies EsnEtmYy. enAeBleRbkg;GaELlBIrmanesßrPaB lkçxNнenHehAfa of two alleles are stable, the condition is called balanced BhusNæanlMnwg. ]TahrN_³ RkumQammnusS. polymorphism. e.g. Human blood groups. genetic recombination : The gene mixing that occurs during bnSMesenTiceLIgvij ³ bnSMEsnEdlekIteLIgenAeBlbnþBUCeday sexual reproduction. ePT. genetic species concept : Two species are considered distinct if TsSn ³esenTicRbePT ³ eKnwgKitfaCaRbePTBIrxusKña ebIsinCa their genetic makeup sufficiently different from one another. sMPar³esenTicrbs;BYkvaTaMgBIrxusBIKña. genetics : The study of heredity. esenTic ³ karsikSaBItMNBUC. genome : A set of all the genes necessary to specify an organism’s esNUm ³ EsnTaMgGs;EdlcaM)ac;edIm,IkMNt;lkçN³TaMgGs;rbs; complete list of characteristics. Pavrs;NamYy. genomic library : The set of fragments of an organism’s smUhesNUm ³ Ggát;TaMgGs;énesNUmrbs;Pavrs;EdlRtUv)aneFVIkøÚn genome that are cloned in a virus or bacterial plasmid. enAkñúg)aøsµItrbs;vIrusb¤)ak;etrI. genophore : A bacterial ADN chromosome; its DNA is not esNUpr ³ ®kUm:UsUmrbs;)ak;etrI. rbs;vaminCab;CamYyRbUetGIun associated with histone proteins like eukaryotic chromosomes. GuIsþÚn dUc®kUm:UsUmBUkGuWkarIy:UteT. genotype : The set of genes present in the cells of an organism. esNUTIb ³ EsnTaMgGs;EdlmanenAkñúgekasikarbs;Pavrs;mYy. genus : A group of similar species. A taxonomic level between family BYk ³ RbePTRsedogKñamYyRkum. kMriténrebobcMENkfñak; enAcenøaHGMbUr and species. nigRbePT. geographic barriers : Geographic features that keep r)aMgPUmisa®sþ ³ lkçN³PUmisaRsþEdlTb;sáat;EpñkepSg²énRbePT different portions of a species from exchanging genes. mYymineGaymankarpøas;bþÚrEsnKña. geographic isolation : The division or separation of a bMENgEcktamPUmisa®sþ ³ karEck b¤karEjkb:UBuyLasüúgeday population by a physical barrier such as a mountain range. r)aMgrUb dUcCaCYrPñMCaedIm. geometric structure : Geometric formula representing a molecule; TMrg;FrNImaRt ³ sNæanFrNImaRttagm:UelKul ehIyGatUmkabUn carbon atoms are assumed to be at each corner and hydrogen atoms RtÚv)ansnµtfasißtenAelIRCugnimYy²nigGIuRdÚEsnminRtÚv)anbgðajeGay are not shown. eXIjeT. geosyncline : Portion of the Earth’s crust that has been sub- FrNIsaMgKøINal; ³ RsTab;sMbkEpndI EdlrgclnarujptcuHeRkam. jected to downward warping. Sediments frequently accumulate kMeTckMNenAkñúgCIGUsIinkøaj. in geosynclines. geotropism : The growth response of a plant to gravity. FrNITMenar ³ tMNblUtlas;rbs;rukçCatieTAtamTMnajEpndI.

germ layer : In the animal embryo, one of the three basic RsTab;xñ ³ RsTab;mYykñúgcMeNamRsTab;sMxan;²TaMgbIrbs;GMRb‘Íy:ug layers (ectoderm, endoderm, mesoderm) from which the various ¬GiucsUEDm-emsUEDm rWGg;dUEDm ¦EdllUtlas;CasrIragÁ nigCalikanana organs and tissues arise in the énstVBhuekasika. multicellular animal. germinal epithelium : 1. The outer cell layer of vertebrate eGBIetlüÚmBUC ³ 1- RsTab;ekasikaxageRkAénGUEvrbs;stV q¥wgkg ovaries that produces follicle cells. 2. The inner layer of seminiferous EdlplitekasikapUlIKul. 2- RsTab;xagkñúgénbMBg;plitEs

glucagon : A hormone secreted by the Islets of Langerhans in the Køúykakug ³ Grm:UnbeBa©jedayGIuLÚLg;ekr:g;énlMEBg EdlbMElg pancreas, that converts glycogen to glucose which is then released into KøIkUEsneGayeTACaKøúykUs ehIybeBa©jcUleTAkñúgQamenAeBlEdl the blood as needed. Its effect is RtUvkar. vaman\T§iBlpÞúyBIGaMgs‘úylIn. opposite to insulin. gluconeogenesis : Synthesis of glucose from several non- kMNKøúykUs ³ karsMeyaKKøúykUsBIm:UelKulminEmnCakabUGIuRdat carbohydrate molecules. It occurs in the liver and kidneys in animals, CaeRcIn. vaekItkñúgeføImnigtMrgenamstV nigkñúgRKab;rukçCati. and in the seeds of plants. glucose (also see Alpha-Glucose C H O and Beta-Glucose) : A common KøúykUs ³ m:UNUsakarItsamBaØEdlmanrUbmnþ 6 12 6EdlRtUv)an monosaccharide whose empirical eRbICaRbPBfamBlcMeBaHPavrs;PaKeRcIn. emIl Alpha-Glucose nig formula is C 6H12 O6 used as fuel in most living things. Beta-Glucose . glutelins : A complex mixture of storage proteins in the grains of KøúyetlIn ³ l,ayRbUetGuInbMrugsaMjaMenAkñúgRKab;RsUvsalI. wheat. glycerol : A three-carbon alcohol -OH with three –OH groups. KøIesr:ul ³ Gal;kulEdlmankabUnbI nigRkúm bI. glycogen : A carbohydrate made of glucose molecules; used as a KøIkUEsn ³ kabUGIuRdatEdlekIteLIgBIm:UelKulKøúykUs nigRtUv)aneRbI food-storage molecule by animals. Cam:UelKulGaharbMrugedaystV. glycogenesis : Synthesis of glycogen within the muscles and kMNKøIkUEsn ³ karsMeyaKKIøkUEsnenAkñúgsac;dMu nigefIøm. liver. glycol : An alcohol with two –OH -OH groups. KIøkul ³ Gal;kulGIuRdúksIulEdlmanRkúm BIr. glycolysis : The anaerobic, stage of cellular respiration in which KIøkUlIs rWkarbMEbkKøúykUs ³ dMNak;kalKµanxül;éndegðImekasika glucose or other carbohydrate is broken down to form pyruvic acid EdlKøúykUs rWkabUGIuRtatepSgeTotRtUv)anbMEbkCaGasIutBIruyvic nig or lactic acid, ATP and NADH. GasIutLak;Tic GaedNUsIunRTIpUsVat ¬ ATP ¦nignIkUTINamIt GaedNUsIunDInuyekøGUTIt ¬ NADH ¦. glycoprotein : A type of protein that has sugars attached to it. eg KøIkURbÚetGIun ³ RbUetGIunmYyRbePT EdlmansárP¢ab;CamYy. extensin in cell walls. ]TahrN_ Gicsþg;sIunenAkñúgPñaseRKag. glycoside : Compound formed when a cyclic sugar is bonded to an KIøkUsIut ³ smasFatuEdlekIteLIgenAeBlsiucsár)anRtÚvP¢ab;eTAnwg alcohol through a glycosidic bond. Gal;kulqøgedaysm<½n§KIøkUsIut. glycosidic bond : Bond between the anomeric carbon of a cyclic sm<½n§KIøkUsIut ³ sm<½n§rvagkabUnGaNUemricénsiucrbs;sárCamYynwg sugar and the –OH group of -OH another sugar or an alcohol. This Rkúm énsárrWGal;kulepSgeTot. sm<½n§enHcgP¢ab;sárCamYyKñakñúg bond links sugars together in GUlIkUsakarIt nigb:UlIsak;karIt. oligosaccharides and polysac- charides. glyoxylic acid cycle : A sequence of biochemical reactions that vdþGasIutKøIGuksIulic ³ lMdab;RbtikmµKImICIv³mYy EdlbMElg converts acetyl-CoA into A carbohydrate. GaesTIlkUGg;suIm eGayeTACakabUGuIRdat.

glyoxysome : A type of microbody that is common in germinating oil KøIGuksIusUm ³ GgÁtUcmYyRbePT EdleRcInmanenAkñúgdMNuHRKab;eRbg seeds and seedlings that arise from them; glyoxysomes contain nigkUneQIEdlduHBIRKab;eRbg. KøIGUsIusUmpÞúkGg;suImEdleFVIktalIkmµ enzymes that catalyze the karbMEbkGasuItxøaj;eGayeTACaGaesTIlkUGg;suIm A. breakdown of fatty acids into acetyl-CoA. glyphosate : The common name of one of the most commonly used KøIhVÚsat ³ eQµaHTUeTArbs;FatuKImIsMlab;esµAEdleKniymeRbIbMput herbicides in agriculture. enAkúñgvis½yksikmµ. goiter : A condition characterized by enlargement of the thyroid Bkk ³ sßanPaBEdlsMKal;edaykarrIkFMénRkeBjTIrU:GIutenAnwgk gland in the neck, often caused by insufficient iodine in the diet. eRcInEtbNþalmkBIkgVHGIuy:UtenAkñúgcMNIGahar. Goldberg-Hogness box ( also Goldberg-Hogness ( TATA box and Hogness box ) TATA box and Hogness box ): A RbGb; b¤ ³ short nucleotide sequence 20 to 30 bp from the start of the tMnlMdab;nuyekøGUTItxøI²manBI20eTA30KU)asecjBIkEnøgcab;epþImén transcription site in eukaryotes. It tMbn;cMlgRkmkñúgGWkarIyU:t. vaKWCakEnøgsMrab;P¢ab;ARN bU:lIEmra:s II . is the binding site for RNA ’ ’ polymerase II. The consensus CaTUeTAtMnlMdab;enHKW 5 – TATAAAA – 3 . sequence is 5’-TATAAAA-3’. Golgi body : A stack of flattened membranes in eucaryotic cells. An Rbdab;kulsIu rW]bkrN_kulsIu rwDictüÚsUm ³ PñasRtYtelIKñasMEb:t² organelle that prepares and stores proteins for secretion. Also called rbs;ekasikaGWkarIy:Ut. FatuekasikaEdlerobcMnigsþúkRbUetGIunsMrab; dictyosome. beBa©j. gonads : The sex organs; the ovaries or testes. RkeBjePT ³ srIragÁePT EdlmanGUEvnigBgsVas. Gondwana : Supercontinent that existed either independently or in kugdVaNa ³ mhaTVIbEdl)anekItmaneLIgedaydac;tÉg rWedayenA close contact with all other major continental land masses throughout y:agCitCamYyTVIbsMxan;²epSgeTot tamry³karvivtþn_stVq¥wgkgrhUtdl; vertebrate evolution until the Bak;kNþals½kemsUsUGuic nigRtUv)anpSMCamYyTVIbenAGDÆeKalxagt,Úg middle of the Mesozoic and was composed of all the modern sm½yeRkayTaMgGs;rYmTaMgGnuTVIb\NÐa. eRbobeFobCamYy Pangea . Southern Hemisphere continents plus the subcontinent of India. Compare Pangea. gonochoristic : Having separate sexes; that is, an individual is ÉkePT ³ EdlmanePTedayELkKña KWÉktþ³mYyCaeQµal rWCajI either male or female, but never “Dioecious” both. “Dioecious” means the same b:uEnþminEmnTaMgBIrePTeT. k¾mann½ydUcKñaEdr. thing. gonorrhoea : A common sexually Neisseria gonorrhoeae transmitted disease caused by the RbemH ³ CMgWqøgtampøÚvePTbNþalmkBI)ak;etrI . bacterium Neisseria gonorrhoeae. Symptoms include discharge of pus eraKsBaØarYmmankarecjxÞúHBIligÁ nigeyanI. from the penis or vagina. grade : A group of organisms having a similar level of Rkat ³ Rkumrbs;Pavrs;EdlmankMritrUbpÁMRsedogKña b:uEnþRbEhlmin organisation but may not have a common ancestor. EmnmanRbPBmkBIbuBVrYmKñaeT. gradualism : The theory stating that evolution occurred gradually RTwsþIvivtþn_snSwm² ³ RTwsþIEdlEcgfa karvivtþRbRBwtþeTAbnþicmþg²Ca with an accumulated series of changes over a long period of time. mYynwges‘rIénkarpøas;bþÚrecHEtekIneLIgkñúgry³eBly:agyUr.

graft : The transfer of a small part of an organism to a larger part of karpSaM ³ karbBa©ÚnEpñktUc1rbs;Pavrs; eTAEpñkFMénPavrs;EtmYy the same organism, or to a different organism. e.g. in animals, skin b¤eTAPavrs;xusKña. ]TahrN_ ³ pSaMebHdUgb¤Es,kcMeBaHstV pSaMEmk graft or heart transplant. In plants, cMeBaHrukçCati. branch or shoot scion. graft versus host disease (GVHD) : In transplants, reaction by cells of karpSaMRbqaMgnwgCMgWrbs;FµÜl ³ kñúgkarbNþúHCalika CaRbtikmµeday the donor against the antigens present on the cells of the host. ekasikaénGñkpþl; RbqaMgTl;nwgGg;TIEsnEdlmankñúgekasikaFµÜl. Ca Often fatal in human bone marrow jwkjab;vabgáeRKaHfñak;dl;Gayu CIvit kñúgkarbNþúHCalikaxYrq¥wgmnusS. transplants. grafting: A type of vegetative propagation in which a scion of karbMe)A ³ RbePTénkarbNþúHrukçCati EdlExñgbMe)Arbs;rukçCatimYyRtUv one plant is attached to the stock of another. )anP¢ab;eTAelITMrExñgbMe)Arbs;rukçCatimYyeTot. gram (g) : Mass of 1 cm 3, or 1 mL, of water. Rkam ³ ma:sénmYysgÞIEm:RtKUbrWmYymIlIølIRtTwk. gram negative : see gram stain. RkamGviC¢man ³ emIl gram stain . gram positive : see gram stain. RkamviC¢man ³ emIl gram stain . gram stain : A crystal violet stain that is retained by gram-positive karbnSIúBN’Rkam ³ karcab;BN’sVayRKIsþal; EdlrkSaBN’eday bacteria and not retained by gram-negative bacteria, after )ak;etrIRkamviC¢man nigkarmincab;BN’eday)ak;etrIRkamGviC¢man alcohol or a similar solvent is bnÞab;BIdak;Gal;kul b¤sarFaturMlayRsedogenHcUleTA. applied. grana : Areas of the chloroplast membrane where chlorophyll RkaNa ³ tMbn;rbs;Pñaskør:U)øas Edlm:UelKulkør:UPIlRtUv)anRbmUlpþMú. molecules are concentrated. granulocyte : A type of white blood cell (leucocyte) that is RkanuyLUÚsIut ³ RbePTéneKasikas EdlekIteLIgBIxYrq¥wg nigman formed in the bone marrow and has granules in its cytoplasm. RKab;²enAkñúgsuItU)øas. RkanuyLÚsIutbgáeLIgRbEhlCa70° Granulocytes make up about 70% énekasikaQams. manRkanuyLÚsIutbIRbePT eosinophils ( 4% ) , of all leucocytes. There are 3 types: eosinophils (4%), basophils (1%) basophils ( 1%) nig neutrophils ( 65% ) . and neutrophils (65%). grassland : A biome in which grasses are the dominant form of valesµA ³ tMbn;CIv³EdlesµAduHeRcInelIslub. vegetation. gravitropism : The growth of roots or stems in response to TMenarTMnajEpndI ³ karlUtlas;rbs;rws rWedImEdlCakareqøIytb gravity. eTAnwgTMnajEpndI. green gland : Excretory organs in the head of a crustacean. RkeBjébtg ³ srIragÁbeB©ajecalsßitenAnwgk,alénRKusþaes . greenhouse effect : The process by which carbon dioxide in the \T§iBlpÞHkBa©k;³ dMeNIrEdl]sµ½nkabUnicenAkñúgbriyakasRsUbyk atmosphere absorbs energy that normally radiates back into space, famBlEdlCaFmµtaPayRtlb;eTAkñúglMhGakasvijeFIVeGaysItuNðPaB causing the temperature of the rbs;briyakasekIneLIg. \Ti§BlenHRsedogKñaeTAnwgsItuNðPaBEdlekIn atmosphere to rise. This effect is similar to the temperature rise in a eLIgenAkñúgpÞHkBa©k;Edr. greenhouse (or glasshouse). grey matter : Nerve tissue in the central nervous system consisting sarFatuRbepH ³ CalikaRbsaTenAkñúgRbB½n§mCÄmNÐlRbsaT Edl mainly of nerve cell bodies. bgáeLIgCasMxan;edaytYekasikaRbsaT.

ground meristem : The fundamental tissue of the apical emCalikaedIm ³ CalikaRKwHénemCalikakMBUlEdlplitEpñksMbk. meristem; produces the cortex. growth hormone : A hormone secreted by the anterior pituitary Grm:UnlUtlas; ³ Grm:UnbeB©ajedaykMBkmuxGIub:UPIs EdlRtYtBinitü that controls growth. karlUtlas;. growth medium : Any substance that allows the growth and mCÄdæanlUtlas; ³ sarFatuEdleFIVeGaymankarlUtlas; nigkar reproduction of an organism. bnþBUCrbs;Pavrs;. growth ring : A band of xylem cells formed in one growing rgVg;lUtlas; ³ RsTab;ekasikasIuELmEdl)ankekItenAkñúgmYyrdUv season. lUtlas; . GTP cap : A molecule of GTP (GTP) 7-methylguanosine triphosphate mYk ³ m:YelKulmYyén 7-emTIlkaNUsuInRTIpUsVat Edl (GTP) that is attached to the 5’ end ARN of a molecule of RNA as P¢ab;eTAnwgcug5 ;énm:UelKul enAeBlkarcMlgRkmcab;epþImeLIg. transcription begins; the GTP cap mYk GTP GackarBar ARN mineGaymankarkat;pþac;epSg² enAeBlvakMBug protects the RNA from degradation as it is being synthesized. RtUv)ansMeyaK. guanine : A nitrogen base (purine) C5H5ON 5 ADN with the formula C 5H5ON 5 found kanIn ³ )asGasUt ¬BuyrIn ¦manrUbmnþ EdlmanenAkñúg in DNA and RNA, which always ARN 319 pairs with cytosine. See p. 319. nig EdlCanic©kalKUCamYysIutUsIun. emIlTMBr½ . guard cells : Crescent-shaped epidermal cells around the stoma ekasikakarBar ³ ekasikaeGBIEDmEdlmanragdUcCacMNitelakEx of vascular plants that regulate stoma size. sßitenACMuvijsþÚm:aténrukçCatimansrésnaMmanmuxgartMrUvTMhMsþÚm:at. gullet : An extension of the oral groove in paramecia that forms Rbehagmat; b¤edImk ³ cMeBaH)a:r:aemsIu KWCacg¥Úrmat;lycUlkñúg food vacuoles; the beginning of the esophagus. EdlbegáItv:aKuyGUlGahar nigEpñkdMbUgénbMBg;Gahar. gum arabic : A gum produced by Acacia senegal the plant species Acacia senegal; C½rGar:ab‘íc ³ C½rEdlplitedayrukçCatiRbePT . this gum is a hemicellulose, which is a complex branched chain C½renHCaeGmIEsluyLÚs EdlCaRcvak;manédsaMjaM EdlpÞúkGar:ab’ÍNUs consisting of arabinose, galactose, kaLak;tYs nigr:amNUs. glucose, and rhamnose. gut : The digestive tube. See alimentary canal alimentary canal. bMBg;rMlayGahar ³ emIl . guttation : The release of liquid water from leaves; caused by root rMPaycMhayTwk ³ karbeBa©jCatiTwkBIsøwkrukçCati EdlbNþalmkBI pressure. sMBaFb¤s. gymnosperms : Group of plants in which the seed is not contained in sIumNUEs ¦³ eksrjITaMgGs;rbs;páamYy. gyrase : One of a class of enzymes known as topoisomerases. Gyrase sIur:as ³ fñak;mYyénGg;suIm dUcCatUbU:GuIsUEmra:s. sIur:asCaGg;suIm converts closed circular DNA to a ADN negatively supercoiled form prior bMElg rgVg;mUleTACaTMrg;GgáÜjxøaMgGviC¢manmuneBlsV½ytMelIgeTV to replication, transcription, or cMlgRkm karbnSMeLIgvij. recombination.

H H substance : The carbohydrate H group present on the surface of red sarFatu ³ RkumkabUGuIRdatmanenAelIépÞeKalikaRkhm. enAeBl blood cells. When unmodified, it O results in blood type 0; when KµankMENERbvaeGayCaQamRbePT enAeBlmankMENERbeday modified by the addition of karbEnßmmU:NUsakarItvaeGayCaQamRbePT A , B nig AB . monosaccharides, it results in type A, B, and AB. habitat : The part of an ecosystem in which an organism lives. kEnøgrs;enA ³ Epñkrbs;zanRbB½n§EdlPavrs;rs;enA. habitat preference : See ecological isolation ecological isolation. cMNg;cMNUlcitþkEnøgrs;enA ³ emIl . habitat, operational : The soil components and moisture, shade, kEnøgrs;enACak;Esþg ³ FatubgádI nigsMeNIm møb; Pavrs;Edlman associated organisms, and other habitat features that directly affect TMnak;TMng niglkçN³énkEnøgrs;enAepSgeTotEdlman\T§iBlpÞal; an organism. eTAelIPavrs;mYy. habituation : A form of learning in which an animal learns to ignore TMlab;/kars‘aM ³ TMrg;énkareron EdlstVeroneFIVFmµtacMeBaHrMejaac a stimulus upon repeated exposure to it. EdlekIteLIgdEdl²cMeBaHva. haem (heme) : A complex organic protoporphyrin ring structure, called a eGm ³ TMrg;siucsrIragÁsaMjaM EdlehAfa EdlCa protoporphyrin, to which an iron atom is bound; heme occur in the kEnøgP¢ab;GatUmEdk. eGmekItmanenAkñúgsuItU®kUmrbs;Pavrs; cytochromes of all organisms and nigkñúgeGm:UkøÜb‘Ínrbs;stV. in the hemoglobin of animals haemocyanin : A blood protein that transports oxygen in mollusks eGm:UsüanIn ³ RbUetGIunQamEdldwknaMGuksIuEsncMeBaHsib,IstV nig and some arthropods. It contains copper ions and is therefore blue. GakRtUb:UtmYycMnYn. vapÞúkGIuy:ugTg;Edg dUecñHehIyeTIbvamanBN’exov. haemoglobin : A protein in red blood cells responsible for oxygen eGm:UkøÚb‘Ín ³ RbUetGIunenAkñúgekasikaQamRkhm Edlr:ab;rgkar transport. It contains iron ions and is therefore red. dwknaMGuksIuEsn. vapÞúkGIuy:ugEdk dUecñHehIyeTIbvamanBN’Rkhm. haemolysis : Swelling and rupturing of a cell that occurs when eGm:UlIs ³ kareLIge):agnigkarpÞúHEbkénekasika EdlekItmaneLIgenA blood cells are placed in a solution of less than isotonic concentration, eBlekasikaQamRtÚv)andak;eTAkñúgsUluysüúgEdlmankMhab;Tab and water moves in through the CagkMhab;GIusUtUnic ehIyTwkRCabcUltamPñasekasika. cell membrane. haemophilia : A sex-linked condition in humans in which the eGm :UPIlIb¤CMgWQamRkkk ³sßanPaBEdlTak;TgnwgePTcMeBaHmnusS blood fails to clot. EdlsMKal;edayQamminkk. hair follicle : A small pocket in the dermis that surrounds a hair. Kl;eram ³ fg;;tUckñúgEDm EdlB½T§CuMvijKl;eram. half-life : The average time it takes for one half of a sample of Bak;kNþalCIvit ³ ry³eBlmFümsMrab;KMrUGatUmviTüúskmµBak;kNþal radioactive atoms to undergo radioactive decay. dMeNIrkarbMEbkviTüúskmµecj. half-reaction : Oxidation or reduction component of a redox Bak;kNþalRbtikmµ ³ smasPaKGuksIutkmµrWerdukmµénRbtikmµ reaction, stated as a separate reaction. erdukEdlCaRbtikmµdac;BIKña.

halogenation : Addition of halogen to an alkene or alkyne; or GaLÚEsnkmµ ³ karbEnßmGaLÚEsneTAelIGal;Esn rWGal;suIn rW by substitution in alkanes. edaykarCMnUskñúgGal;kan. halon : A bromine-based (Br) compound that is especially haLúg ³ smasFatupSMBIRbUm CaFatuRKwH EdleFIVeGayxUcxat destructive to the ozone layer. y:agxøaMgdl;RsTab;GUsUn. haploid : Having half of the full complement of chromosomes. The GabøÚGIut ³ EdlmanBak;kNþaléncMnYnRkUm:UsUmeBjelj. cMnYn reduced number of chromosomes typical of gametes, as opposed to RkUmU:sUmrbs;kaEm:t EdlpÞúyeTAnwgcMnYnDIbøÚGIuténekasikalUtlas;. the diploid number of somatic cells. haplotype : The set of alleles from closely linked loci carried by an GabøÚTIb ³ RkumGaELlBILÚKusCab;KñaEdldwknaMmkedayÉktþ³. individual. hardpan : A hard soil with disrupted structure that may hatepn ³ dIrwgEdlmanTMrg;minl¥ EdlGacekIteLIgedaykarekIneLIg develop through the gradual accumulation of salt residues when bnþiicmþg²énsMNl;GMbil enAeBlEdleKdak;CIGsrIragÁerogral;qñaM inorganic fertilizers are applied edaymiin)anbEnßmsarFatusrIragÁ. CaTUeTAvaraMgsÞHclnaTwkhUrcuH annually without the addition of organic matter; it generally restricts nigrwsrukçCatiduHcak;eTAkñúgdI. the downward movement of water and roots. hardwood : A woody dicot. sac;eQIhab; ³sac;eQIrwgénrukçCatiDIkUTIeldUn. Hardy-Weinberg principle : In a Hardy-Weinberg : large population, without c,ab;;; kñúgb:UBuyLasüúgFMmYy ebIKµanbMlas;lMenA migration, mutation or selection, the frequencies of alleles in a Kµanmuytasüúg rWCMerIseTenaH eRbkg;rbs;GaELlkñúgb:UBuyLasüúgenAEt population will remain constant sßitesßrBICMnan;mYyeTACMnan;mYy. from generation to generation. Haversian canal : A channel running through bone that contains bMBg;haev ³ bMBg;qøgkat;q¥wg EdlmansrésQamnigsrésRbsaT. blood vessels and nerves. heart : A hollow muscular organ that pumps blood through an ebHdUg ³ srIragÁsac;dMuRbehag Edlsb;QameGayrt;BaseBj organism. See cardiac muscle, cardiac muscle, pericardium, atrium, ventricle, pericardium, atrium, ventricle, sarBagÁkay. emIl atrioventricula valves, bicuspid atrioventricula valves, bicuspid valve, tricuspid valve, pacemaker . valve, tricuspid valve, pacemaker. heartwood : The central portion of an older woody stem that no longer xøwmeQI ³ EpñkbNþÚlrbs;edImeQIcas;EdlQb;dwknaMTwk. conducts water. heat : Form of energy exhibited as molecular motion. kMedA ³ sNæanfamBlEdlbgðajtamclnam:UelKul. heat of fusion : Amount of heat that must be added to change 1 g of kMedAénPaBrlay ³ brimaNkMedAEdlRtÚveRbIIedIm,IbMElgrUbFatumYy a material from its solid to liquid state or the amount that must be Rkam BIrwgeTArav rWbrimaNkMedAEdlRtÚvrMedaHecjedIm,IbMElgrUbFatu removed to change the material BIraveTArwg. tMélenHKW 336J (80 cal) sMrab;Twk. from liquid to solid. This value is 336J (80 cal) for water. heat of vaporization : Amount of heat that must be added to change kMedAénrMhYt ³ brimaNkMedAEdlRtÚveRbIedIm,IbMElgrUbFatumYyRkamBI 1 g of a material from its liquid to 2247J (540 cal) its gaseous state. This value is raveTA]sµ½n. cMeBaHTwkbrimaNenHKW . 2247J (540 cal) for water.

heat shock : A temporary response following exposure of cells or ePJacedaykMedA ³ tMNbbeNþaHGasnñ bnÞab;BIkardak;ekasika organisms to raised temperatures. The response involves activation of b¤Pavrs;eGayRtUvnwgsItuNðPaBEdlekIneLIgxusFmµta. tMnbenHrYm a small number of loci, inactivation cMENkeFVIeGayskmµénLÚKusmYycMnYntUc eFVIeGayskmµPaBénLÚKus of previously active loci, and selective translation of heat shock skmµBImun nigbMNkERbsMraMgén ARNm ePJacedaykMedA. vahak;bIdUc mRNA. It appears to be a nearly universal phenomenon observed in Ca)atuPUtsklmYy EdlRtUv)ansegátcab;taMgBI)ak;etrIrhUtdl;mnusS. organisms ranging from bacteria to humans. helicase : A type of enzyme that breaks hydrogen bonds between eGlIkas ³ Gg;suImmYyRbePTEdlpþac;sm<½n§GIuRdUEsnrvagKU)as complementary base pairs of DNA, ADN thereby causing the double strand bMeBjKñaén ehIyeFVIeGayRcvak;TaMgBIrenaHEbkecjCaRcvak;eTal to split into separate single strands. edayELkKña. emIlTMBr½ 319 . See p. 319. helix : Anything of a spiral shape; in biology it refers to the shape of es<ó ³ GVI²Edlmanrages<ó. kñúgCIvviTüa vasMedAelIragrbs; m:UelKul DNA molecules, which occur as ADN 319 double helices. See p. 319. EdlmanragCaes<óBIr. emIlTMBr½ . hemal arch : Structure formed by paired projections ventral to the FñÚeGm:al ³ TMrg;EdlbgáeLIgedayKUsrésQamxageBaHeTArk vertebral centrum and enclosing caudal blood vessels. q¥wgkgEpñkkNþal nigP¢ab;CamYysrésQamEpñkknÞúy. heme : See haem eGm ³ emIl haeme . hemicellulose : Primarily a cell wall polysaccharide of variable eGmIEsluyLÚs ³ b:UlIsakarItPñasekasikaEdlmansmasPaBnig composition and structure; hemicellulose that is secreted by TMrg;ERbRbYl. eGmIEsluyLÚsEdlbeBa©jedayrukçCati®tÚv)aneKehA plants is also called a gum. See faC½r. emIl Gum Arabic . Gum Arabic. hemichordata : A phylum of worm-like animals with close eGmIkred ³ saxaénstVragdUcdgáÚv EdlmanTMnak;TMngy:agCitsñiT§Ca relationships to the chordates; body of proboscis, collar, and trunk, with mYykred. tYRbemay rgVg;CMuvijk nigRbemayEdlmanBYrRbsaTEbb stomochord or rudimentary edIm. notochord. hemizygous : Conditions where a gene is present as a single copy. eGmIsIukUt ³ sßanPaBEdlEsnmYymanlkçN³EtmYy. ]TahrN_ e.g. genes on the X chromosome in X male mammals. EsnsßitenAelIRkUm:UsUm kñúgfnikstVeQµal. heparin : Polysaccharide that functions as an anticoagulant. eG):arIn ³ b:UlIsakarItEdledIrtYCaGñkRbqaMgnwgkMnk. hepatic portal vein : A blood vessel that collects blood from Ev:nTVareføIm ³ srésQamEdlRbmUlQamBIsrésbþÚreBaHevontUc capillaries, in the intestine and delivers it to a second set of bBa¢ÚneTAsrésbþÚrenAkñúgeføIm. capillaries in the liver. herbaceous : Having no woody stem tissue; soft, green stem tissue esµA ³ EdlKµansac;eQI Tn; CalikaedImmanBN’ébtg Edlrs;)anEt that lives for one growing season. mYyrdUvlUtlas;b:ueNÑaH. herbarium : A systematically arranged collection of dried, tiNal½y ³ karRbmYlpþúMEdl)anerobcMtamRbB½n§ énKMrUrukçCati Edl pressed, and mounted plant specimens. ®tUv)ansMgYt ekob nigdak;Rkb. herbivore : A consumer that eats ; only plants. tiNasI ³ GñkeRbIR)asEdlsIuEtrukçCati stVsIuEtrukçCati.

heredity : The passing of traits from one generation to another. tMNBUC ³ karbBa¢ÚnlkçN³BICMnan;mYyeTACMnan;mYyeTot. heritability : A measure of the amount that observed phenotypic lT§PaBtMnBUC ³ rgVas;brimaNEdlPaBxusEbøkKñaénepNUTIbsegát differences for a trait are due to genetic differences. It is a general sMrab;lkçN³mYy EdlbNþalmkBIPaBxusKñaénesenTic. measure of the amount of genetic vaCargVas;TUeTAénbrimaNbMErbMrYlesenTickñúgb:UBuyLasüúgmYy. variation in a population. If heritability for a trait is low, then it ebIlT§PaBtMnBUCsMrab;lkçN³mYymankMritTabeBlenaHvabgðajeGay suggests that environmental factors are mostly responsible for the trait. eXIjfaktþabrisßanman\T§iBlesÞIrTaMgRsugeTAelIlkçN³enaH. hermaphrodite : An organism with both male and female rYmePT rWeTVePT ³ sarBagÁkaymYymanTaMgsrIragÁbnþBUCeQµalpg reproductive organs. e.g. a snail. TaMgsrIragÁbnþBUCjIpg. ]TahrN¾ ³ xüg. heterochromatin : A condensed, darkly staining portion of eGetr:URkÚm:aTIn ³ EpñkRkUm:aTInEdl)anbnSIBN’cas; nigrYjxøaMgEdl chromatin, easily visible by light microscopy. GacemIleXIjy:aggayedaymIRkUTsSn¾BnøI. heterocoelus : Having the articular surfaces of the vertebral centra eGetr:UsWlws ³ EdlmanépÞsnøak;énq¥wgkgEpñkkNþalmanragEkb saddle-shaped, as in modern birds. dUcCacMeBaHbkSIbc©úb,nñ. heterocycle : Cyclic molecule having some atom other than car- eGetr:Usiuc ³ m:UelKulCasiucEdlmanGatUmmYycMnYn CaCagkabUn bon as a structural component of the ring. Some heterocycles are CaFatubgákñúgsiuc. eGetr:UsiucxøHCaGamIn. amines. heterocyst : Nitrogen-fixing cells in some cyanophytes. ekasikaeGetr:UsIus ³ ekasikaP¢ab;GasUténsüaNUPItmYycMnYn. heteroduplex : A double- stranded nucleic acid molecule in which eGetr:UDUbpøic ³ m:UelKulGasuItnuyekøGuicRcvak;eTVEdlRcvak;nimYy² each strand has a different origin. The two strands do not show manRbPBedImxus²BIKña. Rcvak;TaMg2minbgðajKU)asbMeBjKñaeT. complementary base-pairing. TMrg;TaMgenHGacRtUv)anbegáIteLIgkñúgkMLúúgeBlbnSMeLIgvij. These structures may be produced during recombination. heterogametic sex : The sex that produces gametes containing ePTeGetr:UkaEm:t ³ ePTEdlplitkaEm:t manRkUm:UsUmePTxusKña. different sex chromosomes. Usually the male is the tamFmµtaeQµalCaePTeGetr:UkaEm:t b:uEnþcMeBaHParrs;xøH ¬]TahrN_ heterogametic sex, but in some bkSI ¦jICaePTeGetr:UkaEm:t. em)aeGetr:UkaEm:tCaGñkkMnt;ePTrbs;kUn. organisms (e.g. birds) it is the female. It is the heterogametic parent that controls the sex of the offspring. heterogeneous nuclear RNA ARN ARN (hnRNA) : The collection of RNA éNVy:UminesµIsac; ³ bNMþú cMlgRkmenAkñúgéNVy:UEdl transcripts in the nucleus, ARNr , ARNm , ARNt representing precursors and tageGayRBIxWss½r nigdMeNIrqøgkat;eTACa . processing intermediates to rRNA, vak¾tageGay ARN cMlgRkmEdlnwgminRtUv)andwknaMeTAkñúgsuItU)øaspg mRNA, and tRNA. Also represents RNA transcripts that will not be Edr dUcCa SnRNA ( ARNs tUcenAkñúgéNVy:U ) . transported to the cytoplasm, such as snRNA (small nuclear ). heterogenote : A bacterial cell in which the foreign chromosome EGetr:UEsNUt ³ ekasika)ak;etrIEdlbMENkRkUm:UsUmBIeRkAmanGaELl segment carries different alleles than the original chromosome. xus²KñaeRcInRkUm:UsUmedIm.

heterokaryon : A somatic cell containing nuclei from two eGetr:UkarIy:ug ³ ekasikalUtlas;manéNVy:U)anmkBIRbPBBIrepSgKña. different sources. heterosis: A condition in which crossbred organisms are more fit eGetr:UsIus ³ sßanPaBEdlPavrs;bgáat;ExVg manlkçN³smCag than inbred organisms because they have more heterozygotic loci. See Pavrs;bgáat;Cit edaysarEtvamanLÚKuseGetr:UsuIkUteRcInCag. hybrid vigour. emIl hybrid vigour . heterospecific : Belonging to a different species from that under eGetr:URbePT ³ sßitenAkñúgRbePTepSgKña nigsßitenAkñúgkarBiPakSaenA discussion. See also conspecific . eLIy. emIl conspecific . heterosporous plants : Plants with large and small spores; the rukçCatieGetr:Us,: ³ rukçCatiEdlmans,:FM nigs,:tUc s,:tUcCagpþl; smaller give rise to male gametophytes and the larger to kMeNIteTACakaEm:tUPIteQµal nigs,:FMpþl;kMeNIteTACakaEm:tUPItjI female gametophytes (equivalent ¬esµIKñanwg protogymnosperms) . to protogymnosperms). heterotroph : An organism that cannot make its own food and must brCIB ³ Pavrs;EdlminGacbegáItGaharedayxøÜnÉg)anehIyRtUvEt take in nutrients from its environment. TTYleRbIR)as;GaharBIbrisßanrbs;va. heterotroph hypothesis : An idea A.I. Oparin proposed by A.I. Oparin that the smµtikmµbrCIB ³ TsSn³esñIeLIgeday Edlfa Pavrs; first living thing was a heterotroph. dMbUgeKbg¥s;KWCabrCIB. heterotrophic : Capable of using only organic materials as a source brCIB rweGetr:URtUhVic ³ EdlGaceRbIR)as;EtsaFatusrIragá of energy. sMrab;CaRbPBfamBl. heterotrophic organism : Organism that must consume or- Pavrs;brCIB ³ sarBagÁkayEdleRbIR)as;rUbFatusrIragÁedIm,ITTYl)an ganic matter to obtain energy and carbon atoms. famBlnigGatUmkabUn. heterozygote : An organism in which the pair of alleles for a trait eGetrU:sIukUt ³ Pavrs;EdlKUGaELlsMrab;lkçN³mYyRtUv)anbegáIteLIg is composed of different genes (usually dominant and recessive). BIEsnepSgKña ¬CaTUeTAlb; nigGn; ¦. heterozygote superiority : A condition in which individuals ]tþmPaBeGetr:UsIukUt ³ sßanPaBEdlÉktþ³eGetr:UsuIkUtenAelILÚKus heterozygous at one or more loci have higher fitness than an mYyb¤eRcInmanPaBsaksmxøaMgCagÉktþ³EdlmanLÚKuseGetr:UsuIkUttic individual with fewer heterozygous Cag. loci. Hfr : A strain of bacteria exhibiting a high frequency of eRbkg;bnSMx

hill reaction : The photolysis of water and the photoreduction of an RbtikmµhIul ³ karbMEbkTwkedayBnøW nigkarbnßyrsµIénGñkTTYl artificial electron acceptor by eGLicRtugnimit edaykør:U)aøsenAeBlGvtþman CO 2 . chloroplasts in the absence of CO 2. hilum : A scar on a seed where it was attached to the ovary. knþgRKab; ³ sñamelIRKab;EdlP¢ab;eTAnwgGUEv. hinge joint : A type of joint allowing movement in only one snøak;mYyTis ³ RbePTénsnøak;EdlGnuBaØateGaymanclnatam direction. TisEtmYy. histamine : A substance that dilates blood vessels and increases GIusþamIn ³ sarFatuEdleFIVeGaysrésQamrIk nigbegáInkMritCMrab their permeability, causing swelling of surrounding tissue. rbs;va. vabgáeGaymankarehImCalikaenACuMvij. GIusþamInRtUv)an Produced by leucocytes in response plitedayeKalikaskñúgkareqøIytbeTAnwgGg;TIEsnBIeRkA. to foreign antigens. histocompatibility antigens : See HLA HLA. Gg;TIEsnhIusþÚxMEpFIb‘ÍlIFI ³ emIl . histones : Proteins bonded with ADN DNA in the nucleus that comprises GuIsþÚn ³ RbUetGuInPa¢b;CamYy enAkñúgéNVy:U EdlpÞúksmasFatu the protein component of chromatin. They are rich in the RbUetGuInénRkUm:aTIn. vasMbUrGasuItGamIenRKwH dUcCaGasIunIn niglIsuIn basic amino acids arginine and ehIymanmuxgarkñúgkarGgÁÜj ADN kñúgkarbegáItCanuyekøGUsUm. lysine and function in the coiling of DNA to form nucleosomes. emIlTMBr½ 319 . See p. 319. HLA (Human Leucocyte A): A Cell surface proteins, produced by eKalika mnusS ³ RbUetGuInépÞekasikapliteday LÚKus histocompatibility loci, which are involved in the acceptance or hIusþÚxMpaFIb‘ÍlIFIEdlcUlrYmkñúgkarTTYl b¤minTTYlCalikanigsirIragÁpSaM. rejection of tissue and organ grafts and transplants. hn RNA see heterogeneous hn RNA heterogenous nuclear RNA nuclear RNA. ³ emIl . Hogness box : See Hogness Goldberg-Hogness box Goldberg-Hogness box. RbGb; ³ emIl . holandric : A trait transmitted Y from males to males. In humans, EsnCab;RkUm:UsUm ³ lkçN³EdlRtUv)anbBa¢ÚnBIÉktþ³eQaµlmYy genes on the Y chromosome are Y holandric, and are passed from eTAÉkt³eQaµlmYyeTot. cMeBaHmnusS EsnenAelIRkUm:UsUm father to son. CaEsnCab;RkUm:UsUm YnigRtUv)anbBa¢ÚnBI«BukeTAkUnRbus. holocrine gland : Type of gland in which the entire cell is destroyed RkeBjGULÚRKIn ³ RbePTRkeBjEdlekasikaTaMgGs;RtUv)anbMpøaj with the discharge of its contents. apocrine gland See also apocrine gland . enAeBlbeBa©jsarFaturbs;va. emIl . holophytic : (of plants) Using and chlorophyll to make sV½yCIB ³ ¬cMeBaHrukçCati ¦kareRbIBnøWRBHGaTitü nigkørU:PIledIm,IsMeyaK organic compounds. smasFatusrIragÁ. holozoic : (of organisms) feeding on solid organic material that GULÚsUGiuc ³ ¬cMeBaHPavrs; ¦karsuIrUFatusrIragÁrwg² Edl)anmkBI comes from the bodies of other organisms. sarBagÁkayénPavrs;epSgeTot. homeostasis : Maintaining a constant internal environment lMnwgefr ³ karrkSamCÄdæanxagkñúgeGayenAefrdEdl eTaHbIsßanPaB despite changing external conditions. xageRkApøas;bþÚrk¾eday. ]TahrN_ ³ lMnwgsItuNðPaBkñúgxøÜnmnusS EdlminERbRbYleTAtamsItuNðPaBxageRkA.

homeotherms : Animals (mammals and birds) that maintain stVefrkMedA ³ stV ¬fnistV rWbkSI ¦ EdlmansItuNðPaBkñúgxøÜnefr a constant body temperature. Compare poikilotherms. eTaHbIsItuNðPaBbriyakasERbRbÜlxøaMgk_eday. eRbobeFobCamYy poikilotherms . homeotic mutation : A mutation that causes a tissue that would nor- muytasüúgGUemGUTic ³ muytasüúgEdleFVIeGayCalika mally form a specific organ or body part, to change and form ¬EdlCaFmµtanwgbegáItCasrIragÁmYyCak;lak; b¤EpñkénsarBagákay ¦ another structure. Also spelled: pøas;bþÚr nigbegáItCaTMrg;fµImYyeTot. vaGacsresr homoeotic . homoeotic. hominid : Modern humans and closely-related primate ancestors. GUmInIt ³ mnusSsm½yfµI EdlmanTMnak;TMngy:agCiteTAbuBVRBIm:at. homogametic sex : The sex that produces gametes with the same ePTG:Um:UkaEm:t ³ ePTEdlplitkaEm:tmYyRbePTénRkUm:UsUmePT. type of sex chromosome; in mammals, the female is cMeBaHfnikstV stVjICaGUm:UkaEm:t. homogametic. homogeneously staining regions (hsr) : Segments of mammalian tMbn;cab;BN’dUcKña ³ Ggát;RkUm:UsUmfnikstV Edlcab;BN’ chromosomes that stain lightly Giemsa with Giemsa following exposure of RsalCamYy nwgl½x bnÞab;BIkardak;ekasikaeGayRtUvnwgPñak;gar cells to a selective agent. CMerIs. homogenote : A homozygous merozygote. A bacterial GUm:UesNUt ³emr:UsuIkUtGUm:UsuIkUt. emr:UsuIkUtCa)ak;etrIEdlRkUm:UsUm merozygote in which the donor (exogenote) (exogenote) chromosome carries GñkeGay dwknaMGaELldUcKñaeTAnwgRkUm:UsUménGñkTTYl the same alleles as the (endogenote) . chromosome of the recipient (endogenote). homoiotherm : See homeotherm. stVefrkMedA ³ emIl homeotherm . homologous : Having similar structure and origin but having GUmU:LÚk ³ EdlmanTMrg;nigRbPBdUcKña b:uEnþmanmuxgarxusKñacMeBaH different functions in various species. RbePTepSgKña. homologous chromosomes : A pair of chromosomes in a diploid RkÚm:UsUmGUm:ULÚk ³ RkUm:UsUmmYyKUkñúgekasikaDIbøÚGIuEdlmanEsn cell. that contain similar genes at corresponding loci throughout their dUcKñaenAelIGgát;RtUvKña. length. homologous series : Family of -CH compounds differing only by the es‘rIGUm:ULÚk ³ GMbUrénsmasFatuEdlxusKñaEtcMnYnRkúm 2kñúgrUbmnþ. number of -CH 2 groups in the C nH2n+2 formula. eg. The alkane series is ]TahrN_ es‘rIGal;kanRtÚvtagedayrUbmnþTUeTA . represented by the general formula CnH2n+2 . homology : Having identical evolutionary origins and GUm:ULÚsIu ³ EdlmanRbPBvivtþn_niglUtlas;tamrebóbdUcKñaEdlbNþal developing through identical developmental pathways, resulting eGaymanlkçN³dUcKñaenAkñugRbePTepSgKañEdlmanRbPBmkBIbuBVrYm. in the same trait possessed by ]TahrN_ ³ édmnusS nigsøabstV KWGUm:ULUknwgKña. different species that was derived from a common ancestor. eg. The human arm and the wing of a bird are homologous.

homoplasy : Independent evolution of similar or identical GUm:U)øasIu ³ vivtþn_edayÉkraCüénsPaBlkçN³dUcKña rWRbhak;RbEhlKña character states through convergence or parallel evolution. tamry³vivtþn_bRgÜm rWRsbKña. homotherm : See homeotherm. stVefrkMedA ³ emIl homeotherm . homozygote : An individual with identical alleles at one or more GUm:UsuIkUt ³ CaÉktþ³manGaELldUcKñaenARtg;LÚKusmYy b¤eRcIn. loci. Such individuals will produce identical gametes and will Éktþ³rebobenHnwgplitkaEm:tdUcKña nigCaÉktþ³BUCsuT§. therefore breed true. homozygous : A term used to describe an individual with two GUm:UsIukUt ³ BaküeRbIsMrab;BN’naÉktþ³mYyEdlmanGaELlBIrdUcKña identical alleles for a trait. sMrab;lkçN³mYy. honey guide : A pattern of stripes on a flower that directs bees to sBaaØnaMpøúÚvXµMú ³ sñamqñÚt²sßitenAelIpáa EdldwknaMXµúMeGayeTAdl; nectar. Twkdmpáa. hormone: Any chemical regulator that is secreted and transported to Grm:Un ³ GñktMrUvKImIEdlRtUv)anbeB©aj nigdwknaMeTAkEnøgNamYy an area of the body where it causes a response in a tissue or an organ. kñúgsarBagÁkaybNþaleGayCalikab¤srIragÁeqIøytbvij. host : The organism on or in which a parasite lives. FµÜl ³ Pavrs;Edlbrasitrs;enAelIb¤rs;enAkñúgxøÜnva. human immunodeficiency virus HIV (HIV) : A human retrovirus vIrus ¬emeraKeGds_¦ ³ vIrusEdleFVIeGayRbBn§½sauMrbs;mnusS associated with the onset and (AIDS) progression of acquired immuno- cuHexSay CamYynwgkarcab;epþIm nigkarvivtþn_énCMgWeGds_ . deficiency syndrome (AIDS). humerus : The upper bone in the forelimb of tetrapods. See q¥wgedIméd ³ q¥wgEpñkxagelIénGvyv³muxrbs;stVeCIgbYn. sUmemIl pentadactyl limb, and p. 321. pentadactyl limb nigTMBr½ 321 . humoral : Relating to a body fluid, such as blood or lymph. Gu‘ym½r ³ EdlTak;TgeTAnwgvtßúravkñúgxøÜn dUcCaQam rWTwkrég. humus : The organic portion of soil; derived from partially decayed memak ³EpñksrIragÁrbs;dI Edl)anmkBIrukçCati nigstVEdlrlYy. plant and animal material. Hund’s rule : Electrons do not Hund pair (occupy the same orbital) until viFan ³ enAkñúgGrb‘Ítal;RbePTEtmYyeGLicRtúgminsßitenACaKU all orbitals have at least one electron. Electrons are negative eT rhUtTal;EtGrb‘Ítal;TaMgGs; maneGLicRtúgmYyy:agtic. eGLicRtúg and stay as far apart as possible as manbnÞúkGviC¢man ehIysißtenAq¶ayBIeKbMput. long as possible. Huntington’s disease : A Huntington : dominant genetic disorder in which CMgW vibtiþesenTiclubEdlsarFatuEdlRtUv)anplit a substance is produced that interferes with brain function, rMxandl;muxgarxYrk,al bNþaleGay)at;bg;karRtYtBinitüclna k,al causing uncontrolled movements muuux nigGvyv³. of the head, face and limbs. hyaluronic acid : Complex polysaccharide found in connective GasIutGIuy:alYrU:nic ³ b:UlIsakarItsaMujaMuEdlmanenAkñúgCalikasn§an tissue and in bone. nigkñúgq¥wg. hybrid : An individual produced by crossing two pure lines. GIuRb‘Ít ³ Éktþ³Edl)anmkBIkarbgáat;BUCsuT§BIr. hybrid vigor : The increased size and strength of hybrids resulting GIuRb‘ÍtxøaMg ³ GIuRb‘ÍtEdlekInTMhM nigkMlaMgxøaMgEdl)anmkBIkarbgáat; from the cross of two inbred lines. heteros See heterosis. énBUCbgáat;;CitBIr. emIl .

hybridization : 1. Production of offspring from crossing different GIuRb‘Ítkmµ ³ 1- karbegáItkUnecA Edl)anmkBIkarbgáat;RbePTepSg²Kña species or between genetically different populations 2. Rearrange- b¤rvagb:UBuyLasüúgxus²KñaEpñkesenTic. 2- kartMerobeLIgvijén ment of bonding and nonbonding eGLicRtúgcgsm<½n§ nigmincgsm<½n§enACMuvijGatUmEdlekItmankñúgeBl electrons around an atom that occurs during bonding. cgsm<½n§. emIl annealing . See annealing. hybridoma : A somatic cell hybrid produced by the fusion of an GIuRb‘ÍtdUm:a ³ GuIRb‘ÍtekasikalUtlas; Edlplitedaykarrlay antibody-producing cell and a myeloma cancer cell. The cancer cUlKñaénekasikaplitGg;TIkr nigekasikamharIkxYrq¥Åg. ekasika cell contributes the ability to divide mharIkpþl;lT§PaBEckminkMnt; nigekasikaGg;TIkrpþl;lT§PaBeFVI indefinitely, and the antibody cell gives the ability to make large eGay)ancMnYnd¾eRcInénGg;TIkreTal. amounts of a single antibody. hydrated ion : Ion surrounded by water molecules. GIuy:ugGIuRdat ³ GIuy:ugEdlBT§½CMuvijedaym:UelKulTwk. hydration : Addition of water to an alkene or alkyne. An H is added GIuRdatkmµ ³ karEfmm:UelKulTwkeTAelIGal;EsnrWGal;sIun. GIuRdÚEsn to one of the carbon atoms of the –OH double or triple bond, and an –OH RtÚv)anbEnßmeTAelIGatUmkabUnmYyénsm<½n§BIrCan;rWbICan; ehIyRkúm is added to the other carbon atom. π A pi bond is lost. RtÚvEfmeTAelIGatUmkabUnepSgeTot. sm<½n§ RtÚv)at;. hydrocarbon : Compound consisting only of the elements GIuRdÚkabY ³ smasFatuEdlmanEtFatuGIuRdUEsnnigkabUn. GIuRdÚkabY hydrogen and carbon. Hydrocarbons are almost always eRcInEtmanlkçN³minb:UEl. nonpolar. hydrogen acceptor : A particle that can accept hydrogen from FµÜlGIuRdÚEsn ³ PaKl¥itEdlGacTTYlykGIuRdUEsnBIPaKl¥itepSgeTot. another particle. hydrogen bond : Weak attractive forces between the negative region sm<½n§GIuRdÚEsn ³ kMlaMgTMnajexSayrvagtMbn;GviC¢manénm:UelKul of a polar molecule and a positive hydrogen on an adjacent molecule. b:UElnigGIuRdÚEsnviC¢manelIm:UelKulEk,rKña. vamansar³sMxan; Important in determining how kñúgkarkMNt;BIrebobtMerobm:UelKul. groups of molecules are arranged. hydrogenation : Addition of hydrogen to an alkene or alkyne. GIuRdÚEsnkmµ ³ karbUkGIuRdÚEsneTAelIGal;EsnrWGal;sIun. GIuRdÚEsnRtÚv An H is added to both carbon atoms of the double or triple bond, bUkeTAelIGatUmkabUnTaMgBIrénsm<½n§BIrCan;rWbICan; ehIysm<½n§πRtÚv)at;. and a pi bond is lost. hydrolysis : A chemical reaction in which a large molecule is split GIuRdÚlIs ³ RbtikmµKImIEdlm:UelKulFMmYyRtUv)anbMEbkCam:UelKul into two smaller molecules by the addition of a molecule of water. tUc²BIredaykarbEnßmTwkmYym:UelKul. hydronium ion : The ion H 0+ 3 H 0+ that exists in water solutions GIuy:ugGIuRdÚj:ÚUm ³ GIuy:ug 3 EdlmankñúgsUluysüúgTwk BIeRBaHGIuy:ug because the hydrogen ion (H+) is not stable by itself, and so it GIuRdUEsnKµansßirPaBedayxøÜnvadUecñHehIyvarYmpSMCamYymU:elKulTwkmYy. combines with a water molecule. hydrophilic : Readily absorbing or dissolving in water. cMNUlTwk ³ EdlgayRsUbTwkb¤gayrlayenAkñúgTwk. hydrophobic : Tending not to combine with, or incapable of ecosTwk ³ EdlminpSMCamYyTwkb¤minrlaykñúgTwk. dissolving in, water.

hydrophyte : A plant that is adapted to submersion in water or GIuRdUhVIt ³ rukçCatiEdlsMrbxøÜneTArs;enAlickñúgTwk b¤tMbn;TwksMrab; an aquatic environment for at least part of its growing season. ry³eBly:agticmYyEpñkénrdUvlUtlas;rbs;va. eRbobeFobCamYy Compare xerophyte, mesophyte. xerophyte, mesophyte . hydroquinone : Common name for p-hydroxyphenol, an effective GIuRdÚKINUn ³ eQµaHTUeTAsMrab;):ar:aGIuRdúksIuepNulEdlCaGg;TIGuksIudg; antioxidant. manRbsiT§PaB. hydrosphere : The region of the earth containing free liquid water, mNÐlTwk ³ tMbn;enAelIEpndIEdlmanTwk dUcCamhasmuRT bwg Tenø including oceans, lakes, rivers and underground water. nigTwkeRkamdI. hydrostatic skeleton : A constant-volume, fluid-filled cavity eRKaglMnwgTwk ³ RbehagmanGgÁFaturavcMNuHefrEdlrkSaragrbs; that maintains the shape of soft bodied organisms and permits Pavrs;EdlmandgxøÜnTn; nigGnuBaØateGaysac;dMurlavijbnÞab;BIkRnþak;. muscles to be re-stretched after CaTUeTAedaysarKUsac;dMubdibkç. contraction, often through the mutual antagonism of muscle pairs. hydrotropism : Growth of a root toward water. TMenarTwk ³ karlUtlas;rbs;rwseTArkTwk. hydroxyl ion : A negatively OH - charged particle (OH -) composed GIuy:ugGIuRduksIul ³ PaKl¥itEdlmanbnÞúkGKÁIsnIGviC¢man ¬ ¦bgá of oxygen and hydrogen atoms released from a base when eLIgedayGatUmGIuRdUEsn nigGuksIuEsnEdlRtUv)anpþac;ecjBI)asenA dissolved in water. eBlrlaykñúgTwk. hyper- : Prefix meaning greater than. GIuEB ³ CabuBVbTEdlmann½yfaFMCag rWx

hypodermis : One or more layers of cells just beneath the epidermis GIub:UEDm ¬sMbkkñúg¦ ³ RsTab;ekasikamYyb¤ eRcInenACab;BIeRkam that are distinct from the underlying cortical or mesophyll eGBIEDm EdlmanlkçN³xusBIekasikaemsUPIl b¤ekasikaEpñksMbk . cells. hypothalamus : A region of the brain that controls many of the GIub:UtaLamus ³ tMbn;rbs;xYrk,al EdlRtYtBinitüskmµPaBCaeRcInkñúg body’s internal activities that maintain homeostasis. sarBagÁkayEdlrkSaesßrPaBlMnwg. hypothermia : Condition of low- ered body temperature that causes GIub:UETmI ³ sßanPaBfycuHénsItuNðPaBkñúgsarBagÁkay EdlbNþal a decrease in the chemical reactions that support body eGayRbtikmµKImIsMrab;RTRTg;muxgarrbs;sarBagÁkay nigCIvitRtÚvfy functions and life. The chemical cuHEdr. RbtikmµKImIkñúgsarBagÁkaymnusSRbRBwtþeTA)anl¥EtenA reactions in the human body o operate properly only in a narrow sItuNðPaB 37 C. range of temperatures centered on 37 oC. hypothesis : A possible explanation for a set of smµtikmµ ³ karBnül;EdlGaceFIVeTA)ansMrab;karsegátCaeRcIn. observations. hypothyroidism : A condition resulting from the production of karxVHTIr:UGIut ³ sßanPaBEdlbNþalmkBIkarplitTIr:uksIunmin)an insufficient thyroxine. RKb;RKan;. hypotonic : Having a lower concentration of dissolved sub- GIub:UtUnic ³ EdlmankMhab;énsarFaturlayTabCagsUluysüúg Edl stances than the solution to which it is compared. As applied to blood, RtUv)aneRbobeFobCamYy. dUcEdl)anGnuvtþn_elIQam CasUluysüúg a solution that has an ionic con- EdlmankMhab;GIuy:ugTabCagkMhab;Qam. centration less than that of blood. hypotremate : Having the main gill openings on the ventral surface GIub:UERtm ³ EdlmanrgVHRskIebIkcMhenAelIépÞxageBaH nigsßit and beneath the pectoral fins as in skates and rays. See enAxageRkamRBuyRTÚg dUcCacMeBaHRtIkñúgGMbUrbEblCaedIm. pleurotremate. emIl pleurotremate . I I-band : The light zone (composed I : of thin filaments) between the dark bnÞH tMbn;PøW ¬ bgáeLIgedaysrésesþIg² ¦ enAcenøaHrvagbnÞ³yWtexµA bands (composed of thick 325 filaments) that make up the stripes ¬bgáeLIgedaysrésRkas;² ¦ EdlbegáItCasac;duMqñÚt. emIlTMBr½ . of striated muscle. See p. 325. -ic : Suffix indicating the higher of two possible oxidation states. For -Giuc ³ bc©½yEdlbBa¢ak;BIlT§PaBx

Ideal Gas Law : Equation relating gas volume to number of moles of c,ab;]sµ½nbrisuT§ ³ smIkarEdlmanTMnak;TMngrvagmaD]sµ½n gas present, temperature, and PV = nRT pressure: PV = nRT eTAnwgcMnYnm:Ulén]sµ½nRBmTaMgsItuNðPaBnigsMBaF ³ . identical twins : The result of a fertilized egg splitting into two kUnePøaHdUcKña ³ lT§plénkarbMEbksIukUtmYyCaGMRb‘Íy:ugBIrepSgKña. separate embryos. Ig : See immunoglobulin. Ig ³ emIl immunoglobulin . ileum : The last half of the small 322 intestine. See p. 322. GIuelGug ³ EpñkBak;kNþalxagcugeBaHevontUc. emIlTMBr½ . imaginal disk : Groups of cells in endopterygote the pupa of endopterygote insects, fasekasika ³ RkumekasikakñúgdwkeDOénstVl¥it which develop to form the external body parts of the adult, after EdlnwgvivtþeTACaEpñkxageRkAénsarBagákayrbs;Éktþ³eBjv½y metamorphosis. bnÞab;BIbMErbMrYl. imbition : The adsorption of water onto the internal surfaces of karebomTwk ³ sMrUbm:UelKulTwk eTAelIépÞxagkñúgrbs;rUbFatu. materials. imine : Compound formed from the reaction of a carbonyl GIumIn ³ smasFatuekItecjBIRbtikmµénsmasFatu Edlman containing compound and a primary amine. kabUnIlnigGamInfñak;1. immigration : The movement of individuals into a new area. cMNUlRsuk ³ karpøas;kEnøgrbs;Éktþ³eTAenAkEnøgfIµ. immovable joint : A type of joint allowing no movement of the snøak;Gcl½t ³ RbePTénsnøak; Edlq¥wgminGaceFVIclna)an. jointed bones. immune system : A collection of cells and tissues that defends the RbB½n§karBar b¤RbB½n§saMu ³ bNþúMekasika nigCalika EdlkarBar body against pathogens. sarBagÁkayRbqaMgnwgPñak;garbgáCMgW. immunity : The ability to resist a particular disease or infection. PaBsaMu ³ lT§PaBFn;nwgCMgW b¤karqøgCMgWNamYy. immunoglobulin : The class of serum proteins having the eKalikatUcsaMu ³ RkumRbUetGuInesr:UmmanlkçN³Ca Gg;TIk. properties of antibodies. imperfect flower : A flower missing either stamens or a pistil. páaminsuRkwt ³ páaEdlKµankBa©MúeksreQµalrWKµankBa©MúeksrjI. imperfect fungi : See deuteromycetes deuteromycetes. pSitminsuRkwt ³ emIl . imprinting : A type of learning in which an animal forms a social TMlab;stV ³ RbePTénkareronEdlstVbegáItTMnak;TMngsgÁmCamYy attachment to another organism soon after birth or hatching. Pavrs;epSgeTotbnÞab;BIekItb¤jas;Pøam. in situ hybridization : A technique for the cytological GIuRb‘ÍtkmµkñúgmCÄdæanFmµCati ³ bec©keTskMnt;TItaMgkñúgekasikaén localization of DNA sequences ADN complementary to a particular tMNlMdab; bMeBjKñaeTAnwgGasuItnuyekøGuic b¤b:UlInuyekøGUTItNa nucleic acid or polynucleotide. mYy. in vitro : in glass; outside the living organism; occurring in an kñúgEkv ³ enAkñúgEkv. enAxageRkAsarBagÁkayPavrs;. ekIteLIgenA artificial environment. kúñgmCÄdaænnimit. in vivo : in the living; occurring within the living body of an kñúgsarBagÁkay ³ EdlekIteLIgkñúgsarBagÁkayrbs;Pavrs;. organism.

inborn error of metabolism : A biochemical problem that is vibtþiemtabUlIsBIkMeNIt ³ bBaaðKImICIv³EdlRtUv)anRtYtBinitütamEbb genetically controlled; usually an enzyme defect that produces a esenTic ehIyCaTUeTACavibtþiGg;suImEdlbegáItCaeraKsBaaØ. medical symptoms. inbreeding : Crossing two closely related individuals. karbgáat;Cit ³ karbgáat;rvagÉktþ³BIrEdlmanExSRsLayCitKña. inbreeding depression : A condition of poor health or karFøak;cuHénkarbgáat;Cit ³ sßanPaBEdlsuxPaBminl¥ rWlT§PaB decreased fertility after many generations of inbreeding. bgákMeNitfycuH bnÞab;BIkarbgáat;CitCaeRcInCMnan;rYcmk. incisor : A sharp chisel-shaped tooth used for cutting. eFµjcgáÚm ³ eFµjEdlmanragBnøakmuteRbIsMrab;kat;. inclusions : A general term referring to materials inside a cell GgÁkñúg ³ BaküTUeTAEdlsMedAeTAelIsarFatuenAxagkñúgekasika that are usually not readily identifiable; stored materials. EdlCaTUeTAminGackMnt;eGay)anc,as;las;. sarFatuEdlsþúkTuk. incomplete dominance : A situation in which neither allele for lubmineBjelj ³ sßanPaBEdlKµanGaELlmYyNalubelIGaELl a trait is dominant over the other; ; codominance blending. Compare codominance . mYyeToteT layKña. eRbobeFob . incomplete flower : A flower lacking sepals, petals, pistils, or páamineBjelj ³ páaEdlKµanRtbk RsTab; kBa©úMeksrjI b¤kBa©úMeksr stamens. eQµal. incomplete linkage : The breaking apart of genes in the same linkage CMnab;EsnmineBjelj ³ karpþac;EsnenAkñúgRkumCMnab;EsnCamYy group through crossing-over of chromosomal material. Kñatamry³bNþÚrExVgénsMPar³RkUm:UsUm. incomplete metamorphosis : A type of metamorphosis with egg, bMErrUbmineBjelj ³ RbePTbMErrUbEdlmandMNak;kals‘ut dMNak; nymph, and adult stages, but without laval stages . kaldwkedO nigdMNak;kaleBjv½y b:uEnþKµandMNak;kalkUnjas;. incomplete protein : Protein molecules that do not provide all RbÚetGIunmineBjelj ³ m:UelKulRbUetGIunEdlminpþl;GasIutGamIen the essential amino acids. sMxan;²TaMgGs;. incubate : To maintain an environment for eggs so they Rkab ³ rkSabrisßansMrab;;s‘utlUtlas;dl;eBljas;. ]TahrN_³ can mature to hatching. emman;RkabBg. incus : The ear bone that is located between the malleus and q¥wgRTnab; ³ q¥wgRtecokEdlsßitenAcenøaHq¥wgjjÜr nigq¥wgQñan;. the stapes. See ossicle. emIl ossicle . independent assortment : The segregation, or assortment, of one pþac;ecjedayÉkraCü ³ karEjkecjBIKñaedayÉkraCüénRkUm:UsUm pair of homologous chromosomes independently of the segregation, GUm:ULÚkmYyKUBIKURkUm:UsUmepSgeTot. or assortment, of any other pair of chromosomes. indeterminate growth : Growth that is not limited, e.g. a vegetative karlUtlas;KµanTIbBa©b; ³ karlUtlas;EdlKµanRBMEdn . ]TahrN_ apical meristem that produces an unrestricted number of organs ³ emCalikakMBUlrbs;rukçCati EdlplitsrIragÁcMnYnminkMnt; nig\t indefinitely. Qb;Qr. indole-3-acetic acid (IAA) : A naturally occurring auxin. See GasIutGaesTicGIundUl3 ³ GuksIunEdlekIteLIgedayFmµCati. emIl Auxin. Auxin .

induced-fit model : Model for substrate-enzyme interaction that KMrUsMrbKña ³ KMrUGnþrGMeBIrvags‘ubRsþat-Gg;sIum EdlkarP¢ab;s‘ubRsþat states that the binding of substrate to enzyme causes a change in the eTAGg;sIumbNþaleGaymankarpøas;bþÚrTMrg;énm:UelKulmYy rWm:UelKul shapes of one or both of the TaMgBIr. enAeBlvaP¢ab;KñaeTAvijeTAmk enaHvabMeBjKña. molecules. When bound to each other, the two are complementary. inducer : An effector molecule that activates transcription. GñknaMcMlgRkm ³ m:UelKulEdlnaMeGaykarcMlgRkmskmµeLIg . inducible enzyme system : An enzyme system under the control RbB½n§Gg;sIumnaMcMlgRkm ³ RbB½n§Gg;suImenAeRkam karRtYtBinitüén of a regulatory molecule, or inducer, which acts to block a m:UelKultMrUv b¤GñkcMlgRkmEdlbg¥ak;GñkminnaMcMlgRkm nigGnuBaaØt repressor and allow transcription. eGaymankarcMlgRkm. induction : Regulation of gene expression involving the turning on GaMgDucsüúg ³ kMEntMrUvelIkarsMEdgEsnEdlTak;TgeTAnwgkarERbRbÜl of genes by the presence of a compound. kugprm:asüúgénEsnedayvtþmanrbs;smasFatumYy¬GaMgDucT½r ¦. inductor : In embryology, a tissue or organ that causes the GaMgDucT½r ³ kñúgGMRb‘Íy:ugviTüa KWCalika rWsrIragÁmYyEdlbNþal[ differentiation of another tissue or organ. manbMElgÉkeTsénCalika rWsrIragÁepSgeTot. inert gases : Family of gases that are stable as individual atoms, all ]sµ½nkMr ³ GMbUr]sµ½nEdlmansßirPaBkñúgPaBCaGatUmeTal KW]sµ½n having a full complement of outer s p group s and p electrons. They are TaMgGs;mankarbMeBjebjeljéneGLicRtúgxageRkARkum nig . called the noble gases. eKehAvafaCa]sµ½nkMr. infectious disease : Any body disorder caused by the invasion of CMgWqøg ³ vibtþi;sarBagÁkaybNþalmkBIkareRCotcUlénPñak;garbgáCMgW. a pathogen. inferior ovary : An ovary located below the other flower parts on a GUEveRkam ³ GUEvEdlzitenABIeRkamEpñkepSg²eTotrbs;páa. floral axis. infertile : Not able to reproduce. Ga ³ minGacbnþBUC)an. inflammation : A response by damaged tissue that includes rlak ³ tMNbedayCalikaEdlxUc rYmmankarehIm kareLIg Rkhm swelling, redness, soreness, and pain caused by release of nigkarQWcab; EdlbNþalmkBIkarbeBa©jGuIsþamIn. histamines. inflorescence : A specialized branching stem bearing a group of kBa©Múpáa ³ EmkÉkeTskmµEdlRTRTg;páamYykBa©úMEdlduHecjmkCamYyKña. flowers occurring together. infusion : A mixture of water and food material heated to form a cMhug ³ karlayKñarvagTwknigsarFatuGahar daMeGayeTACaTwk clear broth. rMgas;føa. in-group analysis : The assumption in cladistics that the viPaKlkçN³CaRkum ³ karsnµtkñúgviFIcat;CaRkumPavrs;EdlfalkçN³ most common character state is primitive. TUeTAbMputKWlkçN³edIm. inguinal : Relating to the groin. ePøA ³ EdlTak;TgnwgKl;ePøA. inguinal canal : An opening in the floor of the abdominal cavity bMBg;Rkelon ³ rn§bMBg;enAEpñk)aténRbehageBaH EdlBgsVasrbs; through which the testes in a human male fetus descend into the TarkRbusFøak;cuHeTAkñúgfg;sVas. scrotum.

inguinal hernia : A rupture in the abdominal wall that allows a kønlUn ³ karFøayPñaseBaH EdleFIVeGayeBaHevontUcmYyEpñkFøak;cUl portion of the intestine to push through the abdominal wall in the eTAkñúgbMBg;Rkelon. area of the inguinal canal. inheritance : Characteristics passed from generation to tMNBUC ³ lkçN³EdlbBa¢ÚnBICMnan;mYyeTACMnan;mYytamry³sMPar³ generation through the genetic material. esenTic. inhibiting factor : Any of a group of hormones produced by the ktþabg¥ak; ³ RkumGrm:UnplitedayGIub:UtaLamus Edlpþl;sBaØaeTA hypothalamus that signals the pituitary to decrease secretion of a GIub:UPIsedIm,IbnßynUvkarbeB©ajGrm:UnyfaRbePTNamYy. particular hormone. See releasing emIl releasing factor . factor. inhibitor : A molecule that temporarily attaches itself to an Gñkbg¥ak; ³ m:UelKulEdlP¢ab;xøÜnvaCabeNþaHGasnñeTAnwgGg;sIum enzyme, thereby interfering with the enzyme’s ability to form an ehIyraraMglT§PaBrbs;Gg;sIumkñúgkarbegáItkMepøcGg;sIum-s‘ubRsþa. enzyme substrate complex. initiation codon : See start codon. kUdugcab;epþIm ³ emIl start codon . innate behavior : See instinct, instinct, instinctive behaviour instinctive behaviour. Gakb,kiriyaBIkMeNIt ³ emIl . inorganic chemistry : The study of compounds other than KImIGsrIragÁ ³ karsikSaBIsmasFatueRkABIGIuRdUkabYnigRsLayrbs;va. hydrocarbons and their derivatives. inorganic molecules : Molecules that do not contain carbon atoms in m:UelKulGsrIragÁ ³ m:UelKulEdlKµanGatUmkabUnenAkñúgExSbiTb¤ExS rings or chains. Rtg;. insecticide : A poison used to kill insects. fñaMsMlab;stVl¥it ³ fñaMBuleRbIsMrab;sMlab;stVl¥it. insectivores : Insect-eating organisms. )aNkasI ³ Pavrs;EdlsIustVl¥it. insertion : The point of attachment of a muscle to a moving bone. CMnab;sac;duM ³ cMnucEdlsac;dMuP¢ab;eTAnwgq¥wg. insertion sequence : See IS IS element element. tMNlMdab;bBa©Úl ³ emIl . insight learning : Learning in which past experiences are karsikSadkBiesaFn_ ³ karsikSaedayeRbIbTBiesaFn_BIGtIt³kaledIm,I reorganized to solve new problems. edaHRsaybBaðafµI². inspiration : The phase of breathing during which air is taken degðImcUl ³ dMNak;kaléndegðImEdlxül;RtUv)anRsUbcUleTAkñúgsYt. into the lungs. Compare expiration expiration. eRbobeFob . instinct : An innate behavior involving complex responses to a sPavKti ³ Gakb,kiriyaBIkMenItEdlTak;TgnwgdMNbd¾saMjaMueTAnwg stimulus that was not learned. rMejac EdlminEdl)aneron. instinctive behavior : Automatic, preprogrammed, or genetically Gakb,kiriyaekItÉg ³ Gakb,kiriyaEdlkMnt;edayesenTic b¤Gakb,- determined behavior that is clearly not learned. kiriyasV½yRbvtþ EdlBitCaminEdl)aneronesaH.

insulin : A hormone secreted by the Islets of Langerhans in the GaMgs‘uylIn ³ Grm:UnbeBa©jedayGIuLÚLg;ekr:g;énlMEBgEdlman pancreas that functions in carbohydrate and fat metabolism; muxgarkñúgemtabUlIskabUGIuRdat nigxøaj; nigeGaysBaaØeTAelIPaB signals that nutrients are abundant sMbUrén sarFatuciBa©wm nigCMrujskmµPaBGaNabUlIskñúgekasika and stimulates anabolic activity in target cells. eKaledA. integument : The layer or layers of tissue that surround the eRsams,:r:g; ³ RsTab;CalikamYy b¤eRcInEdlB½T§CMuvijemhÁas,:r:g; megasporangium (nucellus) in an ovule; the integument becomes the ¬nuyEsl ¦ enAkñúgGUvul ehIyvakøayCasMbkRKab;. seed coat. intercalary meristem : Meristem / at the base of a blade and/or sheath emCalikacenøaH ³ emCalikaenAKl;søwk nig b¤eRsamRKab;rbs;rukçCati of many monocots. m:UNUkUTIeldUnCaeRcIn. intercalating agent : A compound that inserts between bases in a Pñak;garcenøaH ³ smasFatuEdlERCkcUlcenøaH)askñúg DNA molecule, disrupting the ADN alignment and pairing of bases in m:UelKul Edlbg¥ak;kartMerobCaCYr nigkarpÁÚ)askñúgRcvak;bMeBj the complementary strands (e.g., Kña. ¬]TahrN¾ ³ fñaMbnSIúBN’GaRKIDIn. acridine dyes). interfasicular cambium : The part of the vascular cambium that forms kMbüÚmcenøaH)ac;srésnaM ³ EpñkénkMbüÚmsréskekItenAcenøaH)ac; between vascular bundles and connects with the fascicular srésnaMehIyP¢ab;CamYykMbüÚm)ac;srésnaMenH. cambium interference : A measure of the amount that one crossover affects kareRCotERCk ³ rgVas;brimaNEdlRkUsuIjGUevImYyman\T§iBldl; another crossover in the next region of the same chromatid. RkUsuIjGUevImYyeTotkñúgtMbn;bnÞab;énRkUma:TItdUcKña. kareRCotERCk Positive interference increases the viC¢manbegáIn»kasénRkUsuIjGUevImYyepSgeTot. kareRCotGviC¢manbnßy chances of another crossover; negative interference reduces the nUvlT§PaBénRBwtþikarN¾RkUsuIjGUevITIBIr. probability of a second crossover event. interferon : A blood protein thought to be effective in making GaMgETehVr:ug ³ RbUetGIunQamEdlRtUv)aneKKitfaman\T§iBlkñúgkar some cells resistant to viral attack. eFIVeGayekasikamYycMnYnRbqaMgnwgkarvaylukrbs;vIrus. intermediate filament : The middle-sized (8-12 nm in diameter) PILam:g;mFüm ³ PILam:g;EdlmanTMhMmFüm ¬ EdlmanGgát;p©itBI of the three types of filaments that n.m comprise the cytoskeleton. 8-12 ¦ énPILam:g;TaMgbIRbePTEdlbegáItnUveRKagekasika. internal clock : See biological biological clock clock. em:agxagkñúg ³ emIl . internal fertilization : A type of reproduction in which sperm is karbgákMenItkñúg ³ RbePTbnþBUCEdlEsçmRtUv)an)aj;bBa©Úleday deposited directly into a female’s body. pÞal;eTAkñúgRbdab;bnþBUCjI. internal parasite : A parasite that lives inside its host. brasitxagkñúg ³ brasitEdlrs;enAxagkñúgsarBagÁkayFµÜl. internal respiration : The exchange of gases between the degðImkñúg ³ bNþÚr]sµ½nrvagQamnigekasika. blood and the body cells. interneuron : A nerve cell that transmits information between an NWr:UncenøaH ³ ekasikaRbsaTEdlbBa¢ÚnBt’manrvagNWrU:n\RnÞIy_ nig afferent neuron and an efferent reflex arc neuron. See reflex arc. NWrU:nclkr. sUmemIl .

internode : Part of the stem of a plant between two successive cenøaHfñaMg ³ EpñkénedIm b¤EmkrukçCatiEdlsßitenAcenøaHfñaMgBIr. nodes. interphase : The period of cell growth occurring between cenøaHvKÁ ³ ry³eBllUtlas;rbs;ekasika enAcenøaHcMENkekasika. divisions. interspecific : Relating to phenomena occurring between GnþrRbePT ³ EdlTak;TgeTAnwg)atuPUtEdlekIteLIgrvagÉktþ³én members of different species. RbePTxus²Kña. interspecific competition : Competition between members of karRbNaMgRbECgGnþrRbePT ³ karRbNaMgRbECgrvagsmaCikén different species for the same resource. RbePTepSg²KñaedIm,IdeNþImFnFandUcKña. interstitial : Living in the spaces between sand grains. RbelaH ³ Edlrs;enAcenøaHRKab;xSac;. interstitial cell stimulating (ICSH) hormone : The chemical Grm:UnePJacekasikaRbelaH ³ m:UelKulGñknaMsarKImIbeBa©j messenger molecule released from the pituitary that causes the testes edayGIub:UPIsEdlePJaceGayBgsVasplitetsþÚesþr:Un. etsþÚesþr:UnCa to produce testosterone, the Grm:UnePTeQµalsMxan;CageK. ICSH dUcKñanwgGrm:UnePJacpUlIKul primary male sex hormone. Same as follicle stimulating hormone. (FSH) Edr. intertidal (adj) : Living in the area between high and low and, tMbn;cenøaHTwkeCar-nac ³ Edlrs;enAkñúgtMbn;cenøaHTwk eCar thus, alternately exposed to the air and to the sea. nignac. dUecñHvaRtUvxül;briyakaspgnigRtUvTwksmuRTpg. intervening sequence : See intron intron. emIl . intestine : An organ that functions in the digestion and absorption of eBaHevon ³ srIragÁEdlmanmuxgarrMlayGahar nigRsUbGahar. food. intine : The inner layer of a spore or pollen grain; the intine consists GaMgTIn ³ RsTab;xagkñúgrbs;s,: b¤k¾RKab;lMGg. GaMgTInbgáeLIgeday of cellulose and pectin material that is exported from the EsluyLÚs nigbuicTInEdl)anmkBImIRkUs,:. microspore. intraspecific competition : Competition between members of a karRbNaMgRbECgkñúgRbePT ³ karRbNaMgRbECgrvagsmaCikén population for the same resource. b:UBuyLasüúgedIm,IdeNþImFnFandUcKña. intraspecific : Relating to phenomena occurring between kñúgRbePT ³ EdlTak;TgeTAnwg)atuPUtEdlekIteLIgrvagÉktþ³ members of the same species. TaMgLayénRbePTdUcKña. intrinsic factors : Population- controlling factors that arise from ktþaxagkñúg ³ ktþaRtYtBinitüb:UBuyLasüúgEdlekItecjBIkñúg within the population. b:UBuyLasüúgenaH. introgression : Back-crossing; mating of fertile hybrids with karbgáat;Rtlb; ³ karbgáat;rvagGIuRb‘ÍtCamYynwgb:UBuyLasüúgem)a. parent populations. intron : A sequence of DNA ADN within a gene that does not code GaMgRtug ³ tMNlMdab; kñúgEsnmYyEdlmincMlgRkmsMrab;tMN- for an amino acid sequence. lMdab;GasuItGamIeneT. introvert : A tubular, eversible extension of the head, bearing the RcbUjmat;lUtecj)an ³ k,alragbMBg;GacBnøÚtecj)an manmat; mouth at its tip. enAxagcug.

invagination : An infolding of a layer of tissue to form a saclike karbt;cUl ³ karbt;cUlénRsTab;CalikaedIm,IbgábegáItCaTMrg;dUcfg;. structure. inversion : A chromosomal mutation in which the order of a cMras;Ggát;RkUm:UsUm ³ muytasüúgénRkUm:UsUmEdllMdab;énGgát;RkUm:UsUm chromosome segment has been reversed. RtUv)anRtLb;bRBa©as;cMras;. inversion loop : The chromosomal arrangement resulting from the ePñnbRBa©as ³ kartMerobRkUm:UsUm Edl)anmkBIsuINab;sIusénRkUm:UsUm synapsis of homologous chromosomes, when one of the GUm:ULÚk enAeBlRkUm:UsUmmYydwknaMcMras;Ggát;RkUm:UsUm. chromosomes carries an inversion. invertase : A type of enzyme that catalyzes the breakdown of sucrose GaMgEvtas ³ Gg;suImmYyRbePTEdlkatalIskñúgkarbMEbksárs‘ukRkUs by hydrolysis into glucose and fructose. Also called sucrase . edayGIuRdUlIseGayeTACaKøúykUs nigRPuctUs. eKehAvapgEdrfa sucrase . invertebrates: Animals without backbones. stV\tq¥wgkg ³ stVEdlKµanq¥wgxñg. involuntary muscle: See smooth smooth muscle muscle. sac;duMGqnÞ³ ³ emIl . iodine number : Index used to indicate the degree of unsaturation snÞsSn_GIuy:Ut ³ snÞsSn_EdleRbIsMrab;bBa¢ak;BIkMritminTan; present in a fat or oil. Eq¥tenAkñúgxøaj;rWeRbg. ion : An electrically charged atom or group of atoms; an atom that has GIuy:ug ³ GatUmb¤RkumGatUmEdlmanbnÞúkGKÁIsnI. GatUmmYy)at;rWcMeNj lost or gained electrons and no longer has the same number of eGLicRtúgnig mancMnYneGLicRtugdUcRbÚtugkñúgéNVy:Urbs;va. GIuy:ug electrons as the number of protons viC¢manCakacugnigGIuy:ugGviC¢manCaGaj:úg. in its nucleus. Positive ions are called cations, and negative ions are called anions. ionic bond : Attractive force between two oppositely charged sm<½n§GIuy:ug ³ kMlaMgTMnajrvagGIuy:ugBIrEdlmanbnÞúkpÞúyKña. ions. ionic compound : A compound in which the atoms are held together smasFatuGIuy:ug ³ smasFatuEdlGatUmRtUv)anP¢ab;Kñaedaysm<½n§ by ionic bonds. GIuy:ug. ionic crystals : Substance made of positive and negative ions stacked RkamGIuy:ug ³ sarFatuEdlekIteLIgBIRkúmGIuy:ugviC¢mannigGviC¢man Edl in a regular manner that produce crystals with characteristic shapes. RtYtKñaCarebobeTotTat; EdlbegáItRkamTMrg;Biess² ]TahrN_ GMbil eg. salt (NaCl) crystals are cubic. (NaCl) manragKUb. ionisation constant, water (K ) : w water ionization constant See water ionization constant. efrGIuy:ugkmµénTwk ³ emIl . iris : The colored area of the eye that regulates the amount of light RbRsI ³ EpñkmanBN’rbs;EPñk EdltMrUvbrimaNBnøWqøgkat;rn§RbRsI. admitted to the pupil. irreversible inhibitor : Molecule that binds tightly to an enzyme and Gñkbg¥ak;minGacRtLb;)an ³ m:UelKulEdlP¢ab;eTAnwgGg;sIum reduces or eliminates the activity of the enzyme. y:agENn ehIybnßyrWbM)at;nUvskmµPaBrbs;Gg;sIum. IS element : A mobile DNA IS ADN segment that can be transposed to Fatu ³ Ggát; cl½tEdlGacpøas;bþÚrTItaMgeTAkEnøgd¾éTCa many other sites in the genome. eRcInkñúgesNUm.

island biogeography : A theory explaining the relationship between CIv ³PUmisaRsþtMbn;³ RTwsþIEdlBnül;BI TMnak;TMngrvagkEnøgrs;enANa a defined habitat area (such as an island) and the number and mYy ¬dUcCaekaH1 ¦ CamYynwgcMnYn nignanaPaBénRbePTenAkñúg diversity of species in that area. tMbn;enaH. Islets of Langerhans : Endocrine cells within the pancreas that GIuLÚLg;ekr:g; ³ ekasikabB©ajkñúgsßitenAkñúglMEBg EdlbeBa©j secrete insulin and glucagon. GaMgs‘uylIn nigKøúykakug. isoagglutinogen : An antigen factor or substance present on the GuIsUGaKøúyTINUEsn ³ ktþa b¤ sarFatuGg;TIEsnsßitenAelI surface of cells that can cause the formation of an antibody. épÞekasikaEdlGaceFVIeGaymankarbegáItGg;TIk. isochromosome : A chromosome mutation with two identical arms GuIsURkUmU:sUm ³ muytasüúgRkUmU:sUmEdlmanédBIrdUcKña nigLÚKus and homologous loci. GUmU:LÚk. isocitrate (isocitric acid) : A six-carbon organic acid that loses a GIusUsIuRtat ¬GasuItGuIsUsuIRTic ¦ ³ GasuItsrIragÁEdlmankabUn 6 molecule of carbon dioxide in the third step of the Krebs cycle, Edl)at;bg;]sµ½nkabUnic1m:UelKulenAkñúgvKÁTI 3énvdþERkb ehIyEdlRtUv thereby being converted to )anbMElgeTACagasIutGal;hVaektUKøúytaric. kúñgkMLúgeBl bMElgenaH alpha-ketoglutaric acid; also during + this conversion, one molecule of Edrm:UelKul NAD mYym:UlRtUv)anbnßymkCa NADH . NAD+ is reduced to NADH. isoelectric point (pI) : pH at pH which an amphoteric molecule, cMNucGIusUeGLicRTic ³ Edlm:UelKulGMpUETrdUcCaGasIutGamIen such as an amino acid or protein, has no net charge. b¤RbÚetGIunKµanbnÞúkBit. isogamete : Gametes that are the same size and shape. GIusUkaEm:t ³ kaEm:tEdlmanTMhMnigrUbragdUcKña. isogamy : Reproduction by the union of like gametes. GIusUkamI ³ karbnþBUCedaykarCYbKñarvagkaEm:tdUcKña. isohaline : Of the same salt concentration. GIusUhalIn ³ EdlmankMhab;;GMbildUcKña. isolating mechanism : Any barrier to the exchange of genes between clnkarpþac;edayELk ³ rnaMgénbNþÚrEsn rvagb:UBuyLasüúgepSg different populations of a group of organisms. In general, isolation can KñaénRkumPavrs;. CaTUeTAmankarEjkedayELk GacRtUv)ancat;CaRkum be classified as spatial, tamlMhGakas mCÄdæan b¤tamkarbnþBUC. environmental, or reproductive. isomer : Variations of a particular compound having the same GIusUEm ³ karERbRbÜlénsmasFatuNamYyEdlmanrUbmnþm:UelKul molecular formula but different arrangements of atoms and bonds. dUcKña EtxusKñaRtg;kartMerobGatUm nigsm<½n§. m:UelKulEdlmanrUbmnþ Molecules that have the same m:UelKuldUcKña b:uEnþrUbmnþeRKagxusKña. empirical formula but different structural formulas. isoprene : The basic five-carbon subunit of terpenoid polymers. GIusUERbn ³ ÉktargEdlmankabUnRKwHR)aMénb:UlIEmETEBn. isostasy : Condition of gravitational balance between seg- GIusUsþasIu ³ l½kçx½NÐlMnwgRbCMuTMgn;rvagEpñkepSgénsMbkEpndI rWkar ments of the Earth’s crust or of return to balance after a vilmkrklMnwgvijeRkayBIclnaKµanlMnwg. disturbance. isostatic movement : Vertical displacement of the lithosphere due clnaGIusUsþaTic ³ bMlas;TIbBaÄrénsMbkEpndI edaysarkarpøas;bþÚr to changes in the mass over a point or region of the earth. ma:senAelIcMnuc rWtMbn;NamYyénEpndI.

isotherm : Line on a map that connects points of equal tem- GIusUETm ³ bnÞat;elIEpnTI EdlP¢ab;cMNucEdlmansItuNðPaBesµIKña. perature. isotonic : A term used to describe two solutions that have the same GIusUtUnic ³ BaküsMrab;erobrab;BIsUluysüúgBIrEdlmankMhab;sarFatu concentration of dissolved material. As applied to blood, a rlaydUcKñab¤esµIKña . dUcEdl)anGnuvtþcMeBaHQam KWCasUluysüúg solution that has an ionic EdlmankMhab;GIuy:ugesIµnwgkMhab;Qam. concentration equal to that of blood. isotope : One of two or more forms of an atom having the same GIusUtUb ³ TMrg;mYykñúgcMeNamTMrg;BIr b¤eRcInrbs;GatUm Edlmanelx atomic number and a different atomic mass. Atoms of the same GatUmesµIKña b:uEnþmanm:asGatUmxusKña. GatUmrbs;FatudUcKñaEdlxusKña element that differ only in the EtcMnYnNWRtug. number of neutrons. isozyme : Structurally similar enzymes with similar catalytic GIusUsIum ³ Gg;sIum ¬EdlmanTMrg;Rbhak;RbEhlKñaCamYynwgskmµPaB activity and different metabolic roles, that have the same function katalIsmannaTIkñúgemtabUlIsxusKña ¦ EdlmanmuxgardUcKña but are encoded from different bu:EnþRtÚv)ancMlgRkmecjBIEsnxusKña. genes. J Jacobson’s organ : Tiny pits Jacobson : inside a snake’s mouth that contain srIragÁ rn§tUcsßitenAxagkñúgmat;rbs;Bs;Edlmancug odor-sensing nerve endings. srésRbsaTrYsnwgkøin. jejunum : A short section of the small intestine between the ess‘uynum ³ kMNat;eBaHevontUc EdlsßitenAcenøaHKl;eBaHevontUc duodenum and the ileum. It has a larger diameter and contains larger nigGIuelGug. vamanGgát;p©itFMCag nigmanRcaMgFMCagEpñkepSgeTotén villi than the rest of the small eBaHevontUcehIyCakEnøgEdlsmrUbRsUbGaharPaKeRcInekIteLIg. intestine and is where most absorption of food occurs. joule (j) : SI unit for measurement of heat energy, equal to 0.239 s‘Ul ³ ÉktaénrgVas;famBlkMedAtamRbB½n§GnþrCatiEdlesIµnwg0/239 calories ( 4.2 Joules = 1 cal ). kaLÚrI ¬4/2 s‘Ul = 1 kaLÚrI ¦. K kappa particles : Particles ADN Paramecium containing DNA, found in the pg;ka)a: ³ pg;man RbT³eXIjkñúgsuItU)øasBUCxøHén cytoplasm of some strains of aurelia Paramecium aurelia. When these . enAeBlpg;bnþBUCedayxøÜnÉgTaMgenHRtUv)anbBa¢ÚncUleTAkñúg self-reproducing particles are mCÄdæanciBa©wm vabeBa©jCatiBuleQµaH)a:ra:emsuInEdlsMlab;BUCrYs transferred into the growth medium, they release a toxin, epSgeTot. called paramecin, which kills other sensitive strains. karyokinesis : The process of nuclear division. cMENkéNVyU: ³ dMeNIrkarEckéNVyU:. karyotype : The set of a cell’s chromosomes classified by karIy:UTIb ³ kartMerobRkUm:UsUmrbs;ekasikaeTAtamcMnYn TMhM nigrUb number, size, and shape. rag. kb : See kilobase. kb ³ emIl Kilobase .

kd : See kilodalton. kd ³ emIl Kilodalton . keel : The enlarged breastbone in birds to which the flight muscles q¥wgRTÚgbkSI ³ q¥wgRTUgFMrbs;bkSIEdlCakEnøgP¢ab;sac;dMusMrab;ehIr . are attached. Kelvin scale : Temperature scale Kelvin based on measurement of Rkit ³ RkitsItuNðPaBEp¥kelIrgVas;énclnam:UelKul. molecular motion. At zero Kelvin Kelvin (absolute zero), all molecular tamRTwsþIclnam:UelKulTaMgGs;bBaÄb;enA sUnü ¬sUndac;xat¦. motion theoretically ceases. Kelvin GgSaEklvinmanTMhMdUcGgSaEsls‘üús ehIykarbMElgKW K = oC + 273 . degrees are the same size as Celsius degrees, and the conversion is K = oC + 273. keratin : A fibrous protein found in epidermal tissues and modified ekra:TIn ³ srésRbÚetGIunenAkñúgCalikaeGBIEDm nigbMElgeTACaTMrg;rwg into hard structures, such as horns, hair, feathers and nails. dUcCa Esñg sk; søab nigRkck. keto acids : Organic acids that also contain a carbonyl functional GasIutestU ³ GasIutsrIragÁEdlmanRkummuxgarkabUnIl. group. ketone : Family of organic compounds formed when an alkyl estUn ³ GMbUrsmasFatusrIragÁ EdlekIteLIgenAeBlRkumGal;KIl group is connected to each of the two remaining carbon bonds of the RtÚvP¢ab;eTAnwgsm<½n§kabUnnImYy²énRkumkabUnIlenAsl;BIr. RkúmkabUnIl carbonyl group. The carbonyl minfitenAelIGatUmkabUnxagcugeT. group is not on a terminal carbon atom. ketone bodies : Fuel molecules in the blood that are made from GgÁektUn ³ m:UelKulfamBlkñúgQamEdlekIteLIgBIGaesTIlkUGg;- acetyl-CoA during fatty acid A oxidation, especially in people with sIum kñúgkMLúgeBlGuksIutkmµGasIutxøaj; CaBiessekItmanenAeBl diabetes. Can be used by the brain EdlmnusSmanCMgWTwkenamEp¥m. ehIyvaGaceRbIedayxYrk,al sMrab;eFVI as an alternative fuel to glucose. CafamBlCMnYskøúyKUs. ketose : Monosaccharide containing a ketone group. Note estUs ³ m:UNUsak;karItEdlmanRkúmestUn nigsMKal;edaybuBVbTestU the prefix keto- and the suffice – ose. nigbc©½yGUs. kidney : An organ that excretes nitrogen wastes as urine and tMrgenam ³ srIragÁEdlnaMyksMNl;GasUtecjBIQam nigbgáCaTwk regulates the water balance in the 322 blood. See p. 322. enam ehIytMrUvtulüPaBTwkkñúgQam. emIlTMBr½ . killer T cells : Cytotoxic T T T lymphocytes which recognise and ekasika GñksMlab; ³ LaMpUsiut sIutUtuksIucEdlsÁal;nig kill cells that are infected by , and other abnormal cells. sMlab;ekasikaEdlqøgedayvIrus nwgekasikaxusBIFmµtaepSgeTot. kilobase (kb) : A unit of length consisting of 1000 nucleotides. KILÚ)as ³ ÉktaRbEvgEdlman 1000 nuyekøGUTIt. kilocalorie (kcal) : Unit of heat 1000cal measurement equal to 1000 cal. In KILÚkaLÚrI ³ ÉktargVas;kMedAesIµnwg . enAkñúgcMNIGahar nutrition, the large Calorie is used (Calorie) instead of kilocalories. kaLÚrIFM RtÚv)aneKeRbICMnYsKILÚkaLÚrI. kilodalton (kd) : 1000 daltons. A unit of mass equal to 1000 atomic KILÚdal;tun ³ 1000dal;tun . CaÉktama:sesµIeTAnwg 1000 mass units. e.g. a 70-kd protein has a Molecular Weight of 70 000. Éktama:sGatUm. ]TahrN_ RbUetGuIn70KILÚdal;tun manTMgn;mU:elKus 70 > 000.

kilogram (kg) : Basic SI unit of 1000 mass; 1000 mL of water has a mass KILÚRkam¬K/Rk¦ ³ ÉktaRKwHtamRbB½n§GnþrCatiénm:asKWTwk m/l of 1 kg. manm:asmYyK/Rk. kilometer (km) : Metric unit of 1000m length equal to 1000 m (decimal KILÚEm:t¬K/m¦ ³ xñatRbEvgCaEm:tesIµnwg ¬CaTsPaK Edl prefix kilo- means times 1000). buBVbTKILÚ-mann½yfaKuNnwg 1000 . kinesis : A simple type of behavior involving undirected movement in KIensIus ³ RbePTGakb,kiriyagay EdlTak;TgeTAnwgclnaKµan response to a stimulus. TisedAkñúgtMNbrMejac. kinetic energy : The energy a moving object possesses; the famBlclna ³ famBlrbs;vtßúEdlmanclna. energy of motion. kinetic molecular theory : Idea that molecules in gases are in RTwsþIm:UelKulsIuenTic ³ KMnitEdlfam:UelKulkñúg]s½µneFIVclnaefr. constant motion. kinetin : A purine that acts as a cytokinin. KIenTIn ³ BuyrInEdledIrtYCasIutUKInIn. kinetochore : A disc-shaped complex of proteins that is bound KIentUs½r ³ kMpøicRbUetGIunragdUcfas EdlRtUv)anP¢ab;eTAnwgsg;RtUEm on one side to a centromere and on the other side to a spindle fiber It mçag nigmçageTotP¢ab;eTAnwgsrésRtyUgGaRkUm:aTic. vaP¢ab;RkUm:aTIt connects sister chromatids after bgb¥ÚnTaMgBIrbnÞab;BIkarsV½ytemIøgeTV. replication. Kingdom : The broadest division in taxonomic classification. rC¢³ ³ cMEnkFMCageKbg¥s;enAkñúgkareFIVcMEnkfñak;. kinin : A type of local hormone that is released near its site of KInIn ³ RbePTGrm:UnenAEk,rkEnøgEdlbeBa©jva. origin. Klenow fragment : A part of Klenow ADN bacterial DNA polymerase that Ggát; ³ EpñkmYyén b:UlIEm:ra:s)ak;etrIEdl)at; lacks exonuclease activity, but retains polymerase activity. It is skmµPaBGuicsUnuyekøGas b:uEnþenAmanskmµPaBb:UlIEm:ra:s. vaRtUv)an produced by enzymatic digestion plitedaykarrMlayGaharedayGg;suIménGg;suImmin)anb:HBal;. of the intact enzyme. Klinefelter syndrome : A genetic Klinefelter disease in human males caused by sheraKsBaaØ ¬CMgWexÞIyRbus¦ ³ CMgWesenTickñúg the presence of an extra X X chromosome. Klinefelter males are mnusSRbus EdlbNaþlmkBIvtþmanRkUm:UsUm elIsmYy. CMgWexÞIy XXY instead of XY. This RbusKW XXY CMnYseGay XY . sheraKsBaØaenHrYmmankarrIkFMénedaH syndrome is associated with enlarged breasts, small testes, BgsVastUc Ga ¬minGacbnþBUC)an¦ nigCYnkalviklcarikpg. sterility, and, occasionally, mental retardation. Koch’s postulates : A series of Koch : Robert Koch procedures developed by Robert ]bFarN_ viFImYyes‘rIEdlbegáIteLIgeday edIm,I Koch to determine whether a particular microorganism causes a kMnt;faetImIRkUsarBagÁkaymYyNaEdlbgáCMgW. disease. Kranz anatomy : Specialized leaf Kranz anatomy characteristic of C4 kayviPaKviTüa ³ lkçN³kayviPaKviTüasøwkÉkeTskmµrbs; plants; characterized by having C4 vascular bundles surrounded by a rukçCati EdlsMKal;edayvtþman)ac;srésnaMB½T§CMuvijedayPñas)ac; photo-synthetic bundle sheath. See rsµIsMeyaK. emIlTMBr½ 330 p. 330

Krebs cycle : The series of CO reactions in aerobic cellular vdþERkb ³ es‘rIRbtikmµenAkñúgdegðImmanxül;énekasikaEdlplit 2 respiration, resulting in the ATP production of carbon dioxides, the beBa©jm:UelKulGIuRdUEsn nigkarbegáItm:UelKul . release of pairs of hydrogens, and emIl citric acid cycle . the formation of an ATP molecule. See citric acid cycle. K : see water ionization. w K water ionization constant constant w ³ emIl . kwashiorkor : A protein deficiency disease common in kVasüÚK½r ³ CMgWxVHRbUetGIun eRcInekIteLIgcMeBaHekµgxVHmðÚbGaharbriePaK malnourished children caused by prolonged protein starvation EdlbNþalmkBIkarKµanGaharRbUetGIunbriePakyUreBknaMeGay leading to reduced body size, sarBagÁkaycuHsÁm lðitélð nigR)aCJaGn;fy. lethargy, and low mental ability. L labium : The lower lip of an insect. bbUrmat;eRkamrbs;stVl¥it labor or labour : A period of uterine contractions that eventually QWeBaHqøgTenø ³ ryHeBlénkarkRnþak;s,ÚnEdlrujTarkecjmkeRkA push the baby out of the vagina at birth. tampøÚveyanIenAeBlekIt. labrum : A two-lobed upper lip of an insect. bbUrmat;elIrbs;stVl¥it ³ bbUrxagelIBIrrbs;stVl¥it Edlmanrag mUl. labyrinthodont : A group of fossil stem amphibians from which most Lab‘ÍrauMgfUdug ³ RkumGMbUrkEgábpUsuIl Edlvivtþn_CaGMbUrkEgábeRkay² amphibians later arose. They date from the late Paleozoic. esÞIrEtTaMgGs;. RkumenHekIteLIgtaMgBIcugs½k)a:elGUsUGuic. lack of dominance : See incomplete dominance incomplete dominance . lubmineBjelj ³ emIl . lacteal : A lymph vessel found in the villi of the small intestine. Lak;TIl ³ srésTwkrégEdlsßitenAkñúgRCaMgeBaHevontUc. lactic acid fermentation : An anaerobic process of glucose el,IgGasIutLak;Tic ³ dMeNIrKµanxül;énkarbMEbkKøúykUs EdlbegáIt breakdown that produces lactic acid in microorganisms and the CaGasIutLak;Tic cMeBaHmIRkUsarBagÁkay nigsac;duMskmµrbs;stV. active muscles of animals. lag phase : A period of time following colonization when the dMNak;kalcab;epþIm ³ ry³eBleRkaykarkekItb:UBuyLasüúg population remains small or increases slowly. enAmancMnYntic b¤ekIneLIgyWt. lagging strand : In DNA AND replication, the strand synthesized Rcvak;sMeyaKdac;;;;²² ³ kñúgsVy½tMelIgeTV CaRcvak;sMeyaKtam in a discontinuous way, 5’ to 3’ / / away from the replication fork. rebobminCab;KñatamTis % eTA # ecjBICMBamsVY½ytMelIgeTV. Ggát;xøI Each short piece of DNA nimYy²én ADN Edl)ansMeyaKtamrebobenHehAfa{Ggát;Okasaki }. synthesized in this way is called an Okazaki fragment. See p. 319. emIlTMBr½ 319 . Lamarkism : A false theory Lamark Jean Baptiste Lamark proposed by Jean Baptiste Lamark, RTwsþI ³ RTwsþIxusmYyesñIeLIgeday who suggested that characteristics developed during the lifetime of an )anpþl;eyabl;fa lkçN³EdlkekIteLIgkñúgeBlmanCIvitrbs;Pavrs; organism can be inherited by the mYyGacbBa¢ÚneTACMnan;eRkayeTot. next generation.

lambda phage: bacteriophage that E.coli naturally infects E.coli. pasLaMda ³ Ca)ak;etrIy:UpasEdlP¢ab;eTAnwg . lampbrush chromosomes : The giant chromosomes in vertebrate RkUm:UsUmykS ³ RkUm:UsUmykSkñúgGUv:UsuItstVq¥wgkg ¬PaKeRcIn oocytes (mainly amphibians) that ADN have lateral loops like hairs which GMbUrkEgáb ¦EdlmanrgVg;xagdUceram EdlmanmCÄmNÐl . have DNA centers. large intestine : A part of the digestive system between the small eBaHevonFM ³ EpñkénRbB½n§rMlayGaharsßitenAcenøaHeBaHevontUc nig intestine and rectum that absorbs water from indigestible materials. cugeBaHevon EdlRsUbTwkBIsarFatuminRtUv)anrMlay. larva : A free-living, immature stage in the life history of many kUnjas; ³ dMNak;kalminTan;eBjv½y rs;enAedayesrIkñúgRbvtþiCIvit invertebrate species. énRbePTstV\tq¥wgkgCaeRcIn. larynx : The voice box. A triangular structure at the top of bMBg;sMelg rWRbGb;sMelg ³ TMrg;manragRtIekan the trachea, made of cartilage which contains elastic ligaments sßitenAEpñkxagelIénbMBg;xül; EdlbgáeLIgedayq¥wgx©I mansréscMNg that can vibrate to produce sound. yWtGacjr½begáItCasMelg. late (summer) wood : Wood produced in the summer; sac;eQIrdUvekþA ³ sac;eQIEdlRtUv)anplitenArdUvekþAEdl characterized by relatively small cells. sMKal;edayekasikatUc². lateral : The sides of a bilaterally symmetrical organism. cMehog ³ EpñkcMehogrbs;Pavrs; EdlmansIuemRTIsgxag. lateral bud : A small side bud above each leaf scar that develops BnøkEmk ³ BnøktUcduHenAKl;søwkEdllUtlas;eTACaEmkfµI. into new growth on a twig. lateral line : A sense organ found in fish that is sensitive to pressure qñÚtcMehog ³ srIragÁviBaØaNRtI EdlrYsnwgkarpøas;bþÚrénsMBaF changes caused by movement. bNþalmkBIclna. lateral meristem : Meristem that produces secondary tissue; the emCalikacMehog ³ emCalikaEdlplitCalikaTIBIr. kMbüÚmsrésnaM vascular cambium and cork cambium are examples of lateral nigkMbüÚmt,küaCa]TahrN_emCalikacMehog. meristems. Law of Conservation of Energy : First Law of Thermodynamics See First Law of Thermo- c,ab;rkSafamBl ³ emIl . dynamics. Law of Conservation of Matter : Matter (atoms) cannot be created c,ab;rkSarUbFatu ³ rUbFatu¬GatUm¦minGacRtÚv)anbegIát b¤bMpøajtam nor destroyed by ordinary means. viFIFmµta)an. Law of Definite Proportions : Compound always contains the c,ab;smamaRtkMnt; ³ smasFatuCanic©kalmanFatudUcKña pSMkñúg same elements combined in the proportions by weight. smamaRténTMgn;. Law of Dominance : When an organism has two different alleles c,ab;lub ³ enAeBlEdlPavrs;mYymanGaELlBIrepSgKñasMrab;lkçN³ for a trait, the allele that is expressed and overshadows the mYy GaELlEdlsMEdgecjehIylubelIkarsMEdgecjrbs;GaELl expression of the other allele is mYyeToteKehAfalub. GaELlEdlkarsMEdgrbs;vaminelcecj said to be dominant. The allele whose expression is overshadowed ehAfaGn;. is said to be recessive.

Law of Independent Assortment : Mendel’s second law that states c,ab;énkarpþac;ecjedayÉkraCü ³ c,ab;TIBIrrbs;m:g;Edl Edl that pairs of alleles involved in a cross separate independently. EcgfaKUrbs;GaELlTak;TgeTAnwgkarbgáat;dac;edayELkBIKña. Law of Segregation : Mendel’s first law that states that each c,ab;énkarpþac;ecj ³ c,ab;TImYyrbs;m:g;EdlEcgfa Éktþ³nImYy² individual has two genes for every characteristic and can pass one or manEsnBIrsMrab;RKb;lkçN³TaMgGs; ehIyGacbBa¢ÚnEsnmYykñúgcMenam the other of those genes to its EsnTaMgBIreGayeTAkUnrbs;va EdlmaneRbkg;esµIKña ehIyfamanEt offspring with equal frequency and that only an offspring with two kUnEdlmanEsnGn;TaMgBIreTEdlnwgbgðajBIlkçN³Gn;. recessive genes will show the recessive trait. layering : A type of vegetation propagation in which roots are karbNþúHedayTajEmkkb; ³ RbePTénkarbNþúHrukçCatiedayTajEmk induced to form from a stem. kb;kñúgdI EdlrwsRtUv)anduHecjBIEmkenaH. LD50 : Radiation dose that is lethal to 50 percent of the popula- kMritsøab;50PaKry ³ kMritesµIEdlbNþaleGayb:UBuyLasüúgEdlRtÚv tion being tested. The term LD50 is LD 50 also used for toxic chemicals and )aneKykmkeFIVetsþsøab;50PaKry. Bakü RtÚv)aneRbIsMrab;Fatu drugs. KImIBul nigfñaMeBTüpgEdr. Le Chatelier’s principle : Method Le Chatelier for easily predicting the effect of eKalkarN_ ³ viFIEdlgayRbmaN\Ti§Blénkar changes in reaction conditions on the equilibrium concentration of pøas;bþÚrkñúgl½kçx½NÐRbtikmµelIkMhab;manlMnwgrbs;GgÁFatuRbtikrnigGgÁ reactants and products. It states that FatukekIt. eKalkarN_enHEcgfa lMnwgKimInwggakeTArkxagGgÁFatu a chemical equilibrium will shift to the side of products or reactants so kekItEdkpÞúyBIkarpøas;bþÚrenH. that it will oppose the change. leader sequence or leader region: ARNm ADN Part of a mRNA (or DNA) lMdab;em b¤tMbn;em ³ Epñkrbs;m:UelKul rW cab;BIcug molecule from the 5’ end to the 5’ start codon, immediately next to eTAkUdugcab;epþIm sßitenACab;nwgcMNucepþImEsn. vaGacmantMbn;tMrUv the beginning of a gene. May b¤ tMbn;P¢ab;rIbUsUm. contain regulatory or ribosome binding sites. leading strand: During DNA ADN replication, the strand synthesized Rcvak;sMeyaKCab; ³ kñúgkMLúgeBlsVy½dMeLIgeTV Rcvak;Edl continuously 5’ to 3’ toward the 5’ 3’ replication fork. See p. 319. sMeyaKCab;rhUt tamTisedA eTA eq

leaf scar : A mark left on a twig that indicates the attachment of a sñamTgsøwk ³ sñambnSl;TukelIEmk EdlbBa¢ak;faCakEnøgsøwkduH leaf in a previous season. kalBIrdUvmun. leaf trace : The part of a vascular bundle that extends from the base )ac;srésnaMsøwk ³ Epñkén)ac;srésnaMEdllatsn§wgBIKl;søwkdl; of a leaf to its connection with a vascular bundle of a stem. cMnucEdlvaRtUvP¢ab;eTAnwg)ac;srésnaMrbs;edIm b¤Emk. leaflet : One of many small blades attached to the same petiole. kUnsøwk ³ søwkmYykñúgcMeNamsøwktUc²CaeRcInEdlP¢ab;eTAnwgTgsøwkEt mYy. learning : A change in behavior that results from experience. eg. kareron ³ karpøas;bþÚrGakb,kiriya EdlCaplénbTBiesaFn_. trial and error learning. See habituation, habituation, classical ]TahrN_ ³ karsakl,g nigkMhusénkareron. emIl conditioning, operant classical conditioning, operant conditioning . conditioning. lectin : A type of protein that binds to carbohydrates on cell surfaces; LicTIn ³ RbUetGIunmYyRbePT EdlP¢ab;eTAnwgkabUGIuRdat elIépÞ many lectins are glycoproteins; lectins occur in all parts of the cell ekasika. LicTInCaeRcInKWCaKøIkURbUetGIun ehIyvamanenARKb;Epñkén but are mostly associated with the ekasika b:uEnþPaKeRcInmanenAnwgerTIKuyLÚmGg;dU)aøs nigPñasepSgeTot endoplasmic reticulum and other membranes, including the plasma rYmTaMgPñasekasikapgEdr. membrane legume : The plant family leguminosae which all have one or rukçCatiGMbUrsENþk ³ rukçCatiGMbUrelKuymINWEdlmanRKab;mYy more seed in pods. Many have nitrogen fixing root nodules. eg, b¤eRcInkñugeRsamEpø. rukçCatiGMbUrenHCaeRcInmankMBkrwsP¢ab;GasUt. beans, peas. ]TahrN_ ³ sENþk. lemma : In grasses, the lower part of the two covers of the flowers. sMbkxñgRKab; ³ cMeBaHrukçCatiRkamIen CasMbkxageRkaménsMbkTaMgBIr rbs;páa. lemur : A primitive primate that lives in trees and is active at night sVaknÞúybgág; ³ RBIm:atsm½yedImEdlrs;enAelIedImeQI ehIyva (nocturnal). manskmµPaBenAeBlyb; ¬ raRtIcr ¦. lens : 1. A transparent protein 1 structure behind the pupil that -EkvEPñk ³ TMrg;RbUetGIunføasßitenABIeRkayrn§RbRsIEdlRbmUlBnøW focuses light on the retina. 2. A 2 curved piece of ground, polished eTAelIerTIn. - Lg;TI ³ sMPar³caMgføaEdlmanépÞekageRbIsMrab; material used to refract light. bEgVrBnøW. lentic : Related to an environment in which water is not moving, such Twknwg ¬EdlKµanclna ¦ ³ Tak;TgeTAnwgbrisßanEdlTwkKµanclna as ponds, lakes etc. See Lotic. dUcCa RsH bwg.l. sUmemIl Lotic . lenticel : A group of loosely spaced cells on a stem’s surface Lg;TIEsl ³ RkumekasikaregVIl²enAelIépÞedIm EdlmanmuxgarbþÚr that function in gas exchange. ]sµ½n . leptocephalus larva : Specialized, transparent, ribbon-shaped larva of kUnjas;k,alravtUc ³ kUnjas;bMElgÉkeTsragbnÞHføaEvg tarpons, true eels, and their (tarpons) (true eels) relatives. rbs;RtIdavsmuRT RtITUNa nigRtIkñúgGMbUrenH.

leptotene : The first stage of I prophase 1 of meiosis, during LibtUEtn ³ dMNak;TImYyénRbUpas énemy:Us. kñúgeBlenH which the chromosomes become visible as thin threads. The RkUm:UsUmGacemIleXIjCasrésqµar². RkUm:UsUm)anEckxøÜnCaRkUma:TIt chromosomes have divided into b:uEnþCaFmµtaeyIgminGacemIleXIjRkUma:TItTaMgenHeT. chromatids but these cannot usually be seen. lethal gene : A gene whose effect on the phenotype results in death of Esnbgásaøb; ³ EsnEdlman\T§iBleTAelIepNUTIbehIybgáeGay the organism. Pavrs;søab;. leucine zipper : A pattern in a ADN DNA binding protein that is made KMrUExSrUtLWsIun ³ KMrUkñúgRbUetGuInP¢ab; EdlbegáItedaysMNl; by leucine residues spaced at every 7 seventh amino acid residue, with LWsuInenAelIral;sMNl;GasuItGamIenTI y:ageRcInCamYytMbn;Ek,r² adjacent regions of positively énGasuItGamIenbnÞúkviC¢man. LWsuIn Zippers enAelIRcvak;b:UlIbuibTItBIr charged amino acids. Leucine zippers on two polypeptides may GacmanGnþrGMeBIedIm,IbegáItCaTMrg;DIEmEdlP¢ab;eTAnwg ADN . interact to form a dimer that binds to DNA. leucocyte : See leukocyte. eKalikas ³ emIl leukocyte . leucoplast : A colorless plastid that stores starch. LWkU)aøs ³ )aøsÞItKµanBN’EdlsþúkGamIdug. leukocyte : A common type of white blood cell involved in eKalikas ³ RbePTrYméneKalikasEdlcUlrYmkarBarRbqaMgnwgkar protection from infection. bgáCMgW. leukotrienes : Lipids derived from arachidonic acid that are implicated LWkURTIEG‘n ³ lIBIt)anmkBIGasIutGar:asIudUnicEdlCaEpñkénkareqøIytb in allergic responses. GaElsIu. Lewis acid : Molecule or ion that Lewis can form a coordinate covalent GasIut ³ m:UelKulb¤GIuy:ugEdlGacbegIátsm<½n§kUv:aLg;kUG½rDINa- bond with another species by accepting a pair of electrons. süúgCamYynwgRbePTKImIepSgeTotedaykarTTYleTVtaeGLicRtúg. Lewis base : Molecule or ion that Lewis can form a coordinate covalent )as ³ m:UelKul b¤GIuy:ugEdlGacbegIátsm½

light reactions : The first stage of photosynthesis in which energy RbtikmµPøW ³ dMNak;kaldMbUgénrsµIsMeyaKEdlfamBlBIBnøWRBHGaTitü from the sun is captured as ATP chemical energy to make ATP and RtUv)ancab;ykeFIVCafamBlKImIedIm,IbegIátGaedNUsIunRTIpUsVat ¬ ¦ NADPH.. nignIkUTINamItDInuyekøGUTItpUsVat ¬NADPH ¦. light-compensation point : Light level at which photosynthesis cMNucesµIénBnøW ³ kMritBnøWEdlrsµIsMeyaKesµInwgdegðIm. equals respiration. light-energy conversion stage : The first of the two stages of dMNak;kalbMElgfamBlBnøW ³ dMNak;kalTImYykñúgcMeNamdMNak; photosynthesis, during which light energy is converted to chemical – kalBIrénrsµIsMeyaK EdlfamBlBnøWRtUv)anbMElgeGayeTACafamBl bond energy. sm½

linking number : The number of ADN 2 times that two circular DNA cMnYnbnþP¢ab;Kña ³ CacMnYndgEdl Rcv:ak;eTVragrgVg;mUl duplex strands, cross over each other. KgBIelIKñaeTAvijeTAmk. lipases : Enzymes that catalyze the hydrolysis of ester bonds in fats, lI):as ³ Gg;sIumEdlkatalIsGIuRdÚlIssm½¦ ³ ÉktamaDtamRbB½n§GnþrCatiesIµnwg . lithosphere : Crust of the Earth. sMbkEpndI littoral : Relating to the shallow portion of a lake, sea, or ocean eqñr ³ EdlTak;TgeTAnwgEpñkTwkrak;énbwg smuRT rWmhasmuRT Edl where rooted plants are capable of growing. rukçCatimanrwsGacduHlUtlas;)an. littoral zone : The area of the shore between high and low tMbn;eqñr ³ tMbn;mat;smuRTEdlsßitenAcenøaHTwkCMenarnigTwklMnac. tide marks; intertidal zone. liver : An organ that produces bile, removes toxic materials, and stores eføIm ³ srIragÁEdlbegáItTwkRbmat; bM)at;sarFatuBulecj nigsþúk glycogen. See p. 322. KøIkUEsn. emIlTMBr½ 322 . lock-and-key model : Model for substrate-enzyme interaction that KMrUemesanigkUnesa ³ KMrUsMrab;GnþrGMeBIrvags‘ubRsþa nigGg;sIumEdl states that the two molecules are complementary to each other Ecgfam:UelKulBIrbMeBjKñaeTAvijeTAmkmunnwgP¢ab;Kña nigRtUvKñadUcCa before binding and fit together like emesanigkUnesa. a lock and key. locus (plural, loci) : The place on a chromosome where an allele is LÚKus ¬Bhuvcn ³ LÚsIu¦ ³ cMnucEdlGaELlsßitenAelIRkUm:UsUm. located.

long period interspersion : ADN Pattern of genome organization in KMrUcMruHGgát;Evg ³ KMrurUbpÁMúesNUmEdlCakEnøgGgát; EvgmYy RtUv which long pieces of single copy ADN DNA are interspersed with long )anBRgaylayKñaCamYybMENkEvg²én dEdl². KMrUrUbpÁúMesNUm sections of repetitive DNA. This enHmankñúgRdUsUPIl nigXµMú. pattern of genome organization is found in Drosophila and the honeybee. long terminal repeat (LTR) : Sequence of several hundred base tMNlMdab;EvgenAcug ³ tMnlMdab;KU)asrab;ry EdlmanenAcug pairs found at the ends of retroviral ADNs . rbs;RbtivIrus. long-day plant : A plant that flowers only when the photoperiod rukçCatiéf¶Evg ³ rukçCatiEdlecjpáaEtenAeBlEdlry³eBléf¶yUr is longer than a certain critical amount. Cagry³eBlkMnt;mYy. Loop of Henle : A section of tubule between the proximal and ePñnGg;el ³ EpñkénbMBg;EdlsßitenAcenøaHbMBg;bt;EbnCit nigbMBg; distal tubules of a nephron where urine is concentrated. bt;Ebnq¶ayrbs;enRhVúg kEnøgEdlTwkenamRtUv)aneRcaH. looped domain : A fold or loop in a region of packed chromatin tMbn;ePñn ³ pñt; b¤regVlExSenAkñúgtMbn;srésRkUm:aTInpþúMKñaxøaMgEdllat fibers, which extends out from the main axis of the chromosome. sn§wgBIG½kSemRkUm:UsUm. tMbn;ePñnGacmanpÞúknUvnuyekøGUTItBI20 000eTA Looped domains may consist of 100 000KU. 20,000 to 100,000 nucleotide pairs. lophophorate : Relating to several kinds of marine animals that LÚpUpr ³ EdlTak;TgeTAnwgstVsmuRTCaeRcInRbePT Edlédman possess ciliated tentacles (lophophores) pterobranchs) (lophophores) used to collect food eramj½r sMrab;cab;Gaharrbs;va ¬]- . (eg. pterobranchs). lotic : Related to an environment in which water is moving, such as hUr ¬Edlmanclna ¦ ³ Tak;TgeTAnwgbrisßanEdlTwkmanclna dUcCa rivers. See Lentic. Tenø. sUmemIl Lentic . Lucas test : Test for identifying Lucas whether an alcohol is primary, etsþ ³ etsþsMrab;kMNt;etIGal;kul faetIvaCaGal;kulfñak;1 secondary, or tertiary by its rate of conversion to a chloroalkane. b£fñak;2b£fñak;3tamel,ÓnbMElgrbs;vaeTACakørU:Gal;kan. lumen : A hollow interior space such as the inside of a tube. eg. the Rbehag ³ lMhRbehagxagkñúg dUcCaRbehagbMBg;. ]TahrN_ ³ inside of the small intestine. RbehagkñúgeBaHevontUc. lung : An organ that functions in the exchange of oxygen and carbon sYt ³ srIragÁEdlmanmuxgarbþÚrGuksIuEsnnig]sµ½nkabUnic dioxide with the atmosphere. Vertebrate lungs contain millions CamYybriyakas . sYténstVq¥wgkgmankUnfg;sYtrab;siblan Edl of alveoli in contact with Tak;TgeTAnwgsrésbþÚrCaeRcInEdlpþl;épÞya:gFMsMrab;karbþÚr]sµ½n. capillaries which provide a huge surface area for gas exchange. See emIlTMBr½ 322 . p. 322. luteinizing hormone (LH) : A pituitary hormone that causes a Grm:UnluyetGIun ³ Grm:Unrbs;GIub:UPIsEdleFIVeGaypUlIKulFøay nigvivtþn_ follicle to rupture and then become the corpus luteum. eTACaGgÁelOg.

Lutheran blood group : One of Lutheran many blood group systems RkumQam ³ RbBn§½mYyénRbB½n§RkumQamCaeRcInEdltBUC inherited independently of the ABO, MN, Rh ABO, MN, and Rh systems. edayÉkraCüénRbB½n§ nig . GaELlénRkumenHkMnt; Alleles of this group determine the vtþman b¤GvtþmanénGg;TIEsnenAelIépÞéneKalikaQamRkhm. EsnenH presence or absence of antigens on the surface of red blood cells. This sßitenAelIRkUm:UsUmTI19rbs;mnusS. gene is on human chromosome 19. lymph : Tissue fluid that circulates in the lymphatic vessels similar to Twkrég ³ CalikaravEdlrt;enAkñúgsrésTwkrég EdlRbhak;RbEhl blood but without red blood cells. nwgQamEdr EtKµaneKalikaQamRkhmeT. lymph node : A swelling in a lymph vessel where disease kUnkNþúrTwkrég ³ dMue)a:gsßitenAkñúgsrésTwkrég Edl organisms are removed by white blood cells. mIRkUsarBagÁkaybgáCMgWRtUv)ansMlab;edayeKalikas. lymphatic system : The network of lymph vessels and lymph nodes. RbB½n§Twkrég ³ bNþajsrésTwkrég nigkUnkNþúrTwkrég. lymphocyte : A type of white blood cell that manufactures LaMpUsIut ³ RbePTeKalikasEdlbegáItGg;TIk. antibodies. lyse : To digest or break down. Ebk ³ rMlay rWbMEbk. lysis : The disintegration of a cell brought about by the rupture of its karpÞúHEbk ³ karEbkekasikaedaykarpÞúHFøayPñasrbs;va. membrane. lysogenic bacterium : A bacterial cell carrying a temperate )ak;etrIlIsUEsn ³ ekasika)ak;etrIEdldwknaM)ak;etrIy:Upas EdlRtUv bacteriophage integrated into its chromosome. )anbBa©ÚleTAkñúgRkUm:UsUmrbs;va. lysogenic virus : A type of virus that causes the total destruction of vIrusbMEbk ³ RbePTvIrusEdlbMpøajekasikaTaMgmUl. a cell. lysogeny : The process by which ADN the DNA of an infecting phage lIsUEsnI ³ dMeNIrEdl rbs;pasEdleRCótcUl becomes repressed and integrated into the chromosome of the KµankarsMEdgecj ¬Gt;skmµPaB ¦nigRtUv)anbBa©ÚleTAkñúgRkUm:UsUmén bacterial cell it infects. No new ekasika)ak;etrIEdlvaRCatcUl. KµanpasfIµRtUv)anbegáIteLIgeT. phages are produced. lysosome : A membrane-bound organelle that stores digestive lIsUsUm ³ FatuekasikamanPñasB½T§CMuvij EdlpÞúkGg;sIumrMlay. enzymes. lytic cycle : A reproductive cycle found in viruses where the host cell vdþlITic ³ vdþbnþBUCénvIrusEdlekasikaFµÜlEbkFøay bnÞab;BIkar lyses after producing new virus particles. begIátvIrusfµI². lytic phase : The condition in which a temperate bacteriophage vKÁlITic ³ sßanPaBEdl)ak;etrIy:Upas)at;bg;lT§PaBbBa©ÚlxøÜn loses its integrated status in the host chromosome, replicates, and vaeTAkñúgRkUm:UsUmFµÜl sV½ytMeLIgeTV nigbMEbkekasika)ak;etrI. lyses the bacterial cell. M macroevolution : Evolutionary changes that refer to the m:aRkUvivtþn_ ³ karpøas;bþÚrvivtþn_EdlsMedAeTAelIkarkekItRbePTfµI. development of new species.

macromolecule : An organic molecule made of a very large m:aRkÚm:UelKul ³ m:UelKulsrIragÁEdlbgáeLIgedayGatUmCaeRcIn. number of atoms. macronucleus : An organelle in paramecia and other ciliated m:aRkÚéNVy:U ³ FatuekasikaenAkñúg)a:ra:emsIu nigRbUTIsþmaneramj½r protists that manufactures RNA. epSgeTotEdlbegáIt ARN . macronutrients : Inorganic elements required in large m:aRkUFatuciBa©wm ³ FatusrIragÁEdlRtUvkarkñúgbrimaNeRcInsMrab;kar amounts for plant growth (e.g.. nitrogen, calcium, sulfur). lUtlas;rbs;rukçCati ¬ ]TahrN_ ³ GasUt kal;süÚm nigs‘ulpYr ¦. macrophage : scavenger cells in blood that engulf and digest m:aRkUpas ³ekasikaGñkkMeTcenAkñúgQamEdlelbnigrMlay (phagocytosis) old and damaged red blood cells and other debris. ¬pakUsIutUs ¦eKaliikaRkhmEdlcas;nigxUcxat nigkMeTckMTIepSg²eTot. mad cow disease : See Bovine Bovine spongiform encephalopathy spongiform encephalopathy. CMgWeKaqáÜt ³ emIl . magnification : Enlargement of an object karBRgIk ³ karBRgIkvtßúmYyeGayFM. major histocompatibility loci : MHC See MHC. emIl . malaria : An infectious disease caused by a protozoa (plasmodium) CMgWRKuncaj; ³ CMgWbgáeLIgedayRbUtUsUEG‘ ¬)aøsµÚdüÚm ¦EdlcMlg that is transmitted by Anopheles mosquitoes. Symptoms include edaymUsEdkeKal. eraKsBaØarYmmanRKunekþA kgV³QamRkhm palrIkFM fever, anemia, enlarged spleen, RKunrga nigEbkejIs. chills and sweating. malate (malic acid) : A four- carbon acid that is oxidized by the m:aLat ¬GasIut m:alIc ¦ ³ GasuItmankabUnbYnEdlRtUv)aneFVI reduction of NAD+ to NADH in NAD+ NADH the eighth step of the Kreb’s cycle; GuksIutkmµedaykarbnßy mk enAkñúgvKÁTI8énvdþERkb. malic acid is also formed by the GasIutm:alick¾RtUv)anbegáIteLIgedaykarbnßyGasIutGuksaLÚGaesTic reduction oxaloacetic acid that is derived from fixing carbon dioxide EdlmanRbPBmkBIkarP¢ab;]sµ½nkabUniceTAnwgGasuItpUsVreGNulBIruyvic to phosphoenolpyruvic acid in C4 and CAM photosynthesis. enAkñúgrsµIsMeyaKrbs;rukçCati C4 nig CAM . malleus : The ear bone that is attached to the tympanum. q¥wgjjÜr ³ q¥wgRtecokEdlP¢ab;eTAnwgRtdasRtecok. malnutrition : A condition that occurs when a person does not get kgVHcMNIGahar ³ sßanPaBEdlekIteLIgenAeBlEdlmnusSmin)an enough of the required nutrients. TTYlGaharRKb;RKan;tamtMrUvkar. Malpighian tubules : A group of small tubes branching from the bMBg;ma:l;BIhIu ³ bMBg;tUc²EbkecjBIeBaHevonrbs;GakRtUb:UtelIeKak intestine of terrestrial arthropods that absorb nitrogenous wastes. EdlRsUbsMNl;GasUt. maltase : An enzyme that breaks down the disaccharide maltose. m:al;tas ³ Gg;sIumEdlbMEbkma:l;tUsDIsakarIt. maltose : A disaccharide made of two glucose molecules. ma:l;tUs ³ DIsakarItEdlekIteLIgBIKøúykUsBIrm:UelKul. mammary gland : A gland in female mammals that secretes RkeBjedaH ³ RkeBjrbs;fnikstVjIEdlbeBa©jTwkedaH. milk. mandibles : The jaws of mandibulate arthropods used for fÁamRbNak ³ fÁamrbs;GakRtUb:UtmanfÁameRkamEdlmanmuxgarTMBar chewing food; the lower jaw of 321 vertebrates. See p. 321. Gahar. fÁameRkamrbs;stVq¥wgkg. emIlTMBr½ . mantle : A layer of tissue over a mollusk body that secretes the eRsam ³ RsTab;CalikaRKbdNþb;elIxøÚnsib,IstVEdlbeBa©jsarFatu shell. begáItsMbk.

map unit : A measure of the genetic distance between two xñatEpnTI ³ CargVas;éncMgayesenTicrvagEsnBIr EdlRtUvKña genes, corresponding to a 1 centimorgan recombination frequency of 1 eTAtameRbkg;bnSM PaKry. emIl . percent. See centimorgan. marginal placentation : The attachment of ovules (placentation) CMnab;GUvultamEKm ³ karP¢ab;GUvultambeNþayEKménGUEv. along the edge (margin) of the ovary; long beans have marginal ]TahrN_³ sENþkkYrCarukçCatiEdlmanCMnab;GUvultamEKm. placentation. Markovnikov’s rule : Markovnikov Generalization used to account for viFan ³ karsikSaTUeTAkmµEdleRbIsMrab;kMnt;viFIbUk the way an unsymmetrical reagent HCl (eg. HCl) adds to an unsymmetrical erGak;TIbminsIuemRTI ¬]- ¦eTAelIGal;EsnminsIuemRTI. erGak;TIb alkene. The positively charged EdlmanbnÞúkviC¢man¬]- H+ ¦bUkbEnßmeTAelIGatUmkabUnEdlP¢ab;pÞal; reagent (often H+), adds to the carbon atom directly attached to eTAnwgcMnYnGIuRdÚEsneRcIn. the greater number of hydrogens. marrow : Tissue in the hollows of some bones that produces blood xYrq¥wg ³ CalikakñúgRbehagq¥wgmYycMnYn EdlbegáItekasikaQam b¤sþúk cells or stores fat. xøaj;. marsupial : A pouched mammal. fvikstV ³ fnikstVEdlmanfg;dak;kUn. ]-kg;KUrU. mass : Measure of the amount of matter, independent of grav- m:as ³ rgVas;brimaNrUbFatuEdlminTak;TgeTAnwgEdnkMlaMgTMnaj. itational field strength. See weight. emIl weight . mass number : The weight of an atomic nucleus expressed in atomic cMnYnm:as ³ TMgn;rbs;éNVy:UGatUmEdltagedayÉktam:asGatUmmic mass units. (The sum of the protons and neutrons.) ¬cMnYnRbUtugnigeGLicRtug ¦. mass selection : Choosing individuals with desired traits from CMerIsm:as ³ kareRCIserIsÉktþ³ecjBIRkumFMeTAtamlkçN³Edl a large group. cg;)an. masturbation : Stimulation of one’s own sex organs. kareFIVeGaymansMerIb ³ karePJacsrIragÁePTedayxøÜnÉg. maternal effect : Phenotypic effects on the offspring produced \T§iBlBImaþy ³ \T§iBlepNUTIbelIkUnEdlbegáIteLIgedayCalika by the maternal tissue. Factors transmitted through the egg mþay. ktþabBa¢Únqøgtamry³suItU)øass‘utEdlbegáIt\Ti§BlepNUTIbeTA cytoplasm which produce a dl;CMnan;kUn. ]TahrN_³ \T§iBlrbs;mþayEdlCk;)arI phenotypic effect in the progeny. e.g. the effect of a mother who eTAelITMgn;TarkminTan;ekItrbs;nag. smokes on the weight of her unborn baby. maternal influence : See maternal effect maternal effect. \TiÞBlBImþay ³ emIl . maternal inheritance : The transmission of traits by genetic tMnBUCtamry ³em ³ karbBa¢ÚnlkçN³edayktþaesenTickñúgsuItU)aøs factors in the cytoplasm such as mitochondria or chloroplasts. dUcCamItUkugRDI b¤kør:U)øas. matrix : A nonliving material secreted by osteocytes; the fluid m:aRTic ³ 1- sarFatuKµanCIvitbeBa©jedayekasikaq¥wg. inside a mitochondrion. 2- sarFaturavenAkñúgmItUkugRDI. matter : Anything that has mass and occupies space. rUbFatu ³ GVI²Edlmanma:s nigmanTItaMgkñúglMh.

maxilla : One of the upper 321 jawbones in vertebrates. See p. 1- fÁamelI ³ q¥wgfÁamelIénstVq¥wgkg. emIlTMBr½ . 321; one of the head appendages in arthropods. 2- Exñgk,alcMeBaHGakRtÚb:Ut. maxillary teeth : Small teeth inside the upper mouth of frogs. eFµjfÁamelI ³ eFµjtUc²enAxagkñúgmat;EpñkxagelIrbs;kEgáb. maxilliped : An appendage in crustaceans used in feeding and ExñgeCIg ³ Exñgrbs;RKusþaeseRbIsMrab;cab;cMNIGahar nigCaFµÜl sensory reception. viBaØaN. mean : The arithmetic average. mFüm ³ mFümnBVnþ. measles : A serious childhood Morbilli disease caused by the Morbilli kRBaw¢l ³ CMgWkumarF¶n;F¶r EdlbNþalmkBIvIrus . virus. Symptoms include round red spots on the skin, cough, fever and eraKsBaØarYmmanknÞÜlRkhmenAelIEs,k k¥k RKunekþA nigQWbMBg;k. sore throat. mechanical digestion : The physical breakdown of food by rMlayGaharemkanic ³ karbMEbkGahartamlkçN³rUb edaykar chewing and by the muscular churning of the stomach. TMBar nigkarRc)ac;cuHeLIgedaysac;duMRkBH. median : 1. In statistics, the middle 1 value in a group of numbers. There emdüan ³ -kñúgsaþTIsÞic CatMélkNaþlkñúgcMnYnmYyRkum. mancMnYn is an equal number of data points or measurements below and above esµIKñamYyéncMnucTinñn½y b¤rgVas;BIelInigBIeRkamtMélemdüan. the median value. 2. In structures, a 2-bnÞat;EdlEckPavrs;CaBIrcMehogesµIKañ. line that divides an organism into two equal halves. Mediterranean scrub : The often dense, shrubby vegetation that éRBtMbn;emDIETra:en ³ dMNuHrukçCatiEdlmanlkçN³CaKem

megaspore mother cell : A cell that will undergo meiosis and ekasikaememhÁas,: ³ ekasikaEdlnwgeFVIemy:Us nigcMEnkekasika cytokinesis to produce megaspores. edIm,IbegáItemhÁas,:. megasporophyll : The leaf-like organ that bears megasporangia. emhÁas,:r:UPIl ³ srIragÁdUcsøwkEdlpÞúkemhÁas,:r:g;. meio-blastospore : A spore that arises by budding from a haploid, emy:U-)aøssþÚs,: ³ s,:EdlekIteLIgedaykarduHBnøkecjBIs,:GabøÚGIut meiotically produced spore. EdlekIteLIgedayemy:Us. meiofauna : Small, interstitial animals living between sand emy:UhVÚNa ³ stVtUc²Edlrs;enAcenøaHRKab;xSac;. grains. meiosis : A process of cellular division in which the number of emy:Us ³ dMeNIrEckekasikaEdlcMnYnRkUm:UsUmRtUv)anbnßyBak;kNþal chromosomes is reduced by half from the diploid to the haploid BIDIbøÚGIuteTAGabøÚGuIt. number. meiosis I : The first of two nuclear I divisions that, in plants, form emy:Us ³ cMENkTI1éncMENkéNVy:UBIr EdlbegáIt)anCas,:cMeBaH spores; in meiosis I, homologous I chromosomes synapse, cross over, rukçCati. kñúgemy:Us enH ®kUm:UsUmGUm:ULÚkxitmkCab;KñaeFVIRkUsuIjGUevI and move to opposite poles of the ehIyeFVIdMeNIreTAkan;b:UlpÞúyKñaénRty:UgGaRkUm:aRTic. karEjkdac;BIKña meiotic spindle apparatus; the separation of homologous én®kUm:UsUmGUm:ULÚkenAkñúúgemy:Us eFVIeGaymankarfycMnYn®kUm:UsUm chromosomes in meiosis results in a reduction in chromosome number Bak;kNþalcMeBaHéNVy:UkUn. by one-half in daughter nuclei. meiosis II : The second of two II nuclear divisions that, in plants, emy:Us ³ cMENkTI2éncMENkéNVy:UBIrEdlbegáIt)anCas,:cMeBaH form spores; in meiosis II, II centromeres divide and sister rukçCati. kñúgemy:Us enH sg;RtUEmEckxøÜnehIyRkUm:aTItbgb¥ÚnkøayCa chromatids become independent RkUm:UsUmÉkraCü EdleFVIdMeNIreTAkan;b:UlpÞúyKñaénRty:UgGaRkUm:aTic. chromosomes that move to opposite poles of the spindle apparatus. meiospore : A haploid spore that results from meiosis emy:Us,: ³ s,:GabøÚGIutEdl)anmkBIemy:Us. melanin : A dark pigment found in skin, hair, the iris and choroid in emLanIn ³ CatiBN’exµAEdlmanenAkñúgEs,k sk; RbRsIEPñk nig the eye. kUr:UGIutEPñk. melanoma : A very serious cancer of melanin-producing cells that emLaNUm:a ³ CMgWmharIkF¶n;F¶rénekasikaplitemLanIn appears as a dark mole on the skin. EdlelceLIgCasñamRbRCuyexµAenAelIEs,k. melting point : Temperature at which a substance in the solid state cMNucrlay ³ sItuNðPaBEdlsarFaturwgRtÚv)anbMElgeGayeTACa is converted to the liquid state. The freezing point is the same rav. cMNuckMnkmansItuNðPaBdUcKñaEdr b:uEnþbMErbMrYlkñúgTispÞúyKña. temperature, with the change in the opposite direction. melting profile : See T melting m T melting temperature, transition temperature, transition sItuNðPaBrlay ³ emIl m temperature. temperature . membrane potential : The potential electrical energy of ions b:Utg;EsülPñas ³ famBleGLicRTicb:Utg;Esülrbs;GuIy:ugqøgkat; across a membrane; membrane potential is measured in volts. PñasmYy. b:Utg;EsülPñasRtUv)anKitCav:ul.

membrane selectivity : The control that a membrane exerts PñasCMerIs ³ karRtYtBinitüemIlfaetIPñasmYy eRbIR)as;elIsb:unµan nig over how much and what kinds of materials pass through it. FatuGVIEdlqøgkat;va. membrane system : The interconnected membranes of a RbB½n§Pñas ³ PñasGnþrTMnak;TMngekasika edayrYmmanPñasekasika cell, including the plasma membrane and the various nigPñasFatuekasikaepSg²CaeRcIneTot. organelle membranes. membranes : Sheet-like structures in cells that separate the cell Pñas ³ TMrg;dUcCaRsTab;énekasika EdlEjkEpñkcagkñúgénekasikaxag interior from the external environment and divide the cell kñúgBIbrisßanxageRkA nigEckEpñkxagkñúgénekasikaCaeRcInft. interior into compartments. memory cell : A type of B-cell B that remains in the body after ekasikaemm:rI ³ RbePTekasika EdlsßitenAkñúgxøÜnbnÞab;BIkarbgáCMgW. infection. Mendelian genetics : The pattern of inheriting characteristics that esenTicm:g;Edl ³ KMrUlkçN³dMNBUC EdlGnuvtþtamc,ab;EdlbegáIt follows the laws formulated by Gregor Mendel Gregor Mendel. eLIgeday . meninges : Protective membranes covering the brain and spinal cord. eRsamxYr ³ PñaskarBarEdleRsabxYrk,alnigxYrq¥wgxñg. cMeBaHfnikstV In mammals these are the dura dura mater, arachnoid, and pia mater mater, arachnoid, and pia mater. RsTab;enHmanbICan;KW . meniscus : The curved surface of a liquid where it touches a container épÞekagénvtßúrav ³ épÞekagénvtßúravEdlb:HeTAnwgbMBg;bgáeLIgeday caused by capillarity. eg. water in a test tube. ExPIl½rrIFI. ]TahrN_ ³ TwkenAkñúgbMBg;sak. menopause : The period II beginning at about age fifty when karGs;rdUv ³ ry³eBlEdlGUEvQb;plitGUvUsIut nigGrm:UnGUEv KWcab; the ovaries stop producing viable secondary oocytes and ovarian epþImenAGayuRbEhl50qñaM. eBlQb;mankarbnþBUCénmnusSRsI. hormones; when reproduction karElgmanrdUv. ceases in the human female; end of the ability to menstruate. menstrual cycle : monthly hormonal changes causing vdþrdUv ³ karERbRbYlGrm:Unral;Ex EdlbNþaleGaymandMeNIrGUvul ovulation and preparation of the uterus for a possible pregnancy. nigkareRtomlkçN³éns,ÚnsMrab;karmanépÞeBaHEdlGacekItman. menstruation : A period in the menstrual cycle in which the karFøak;rdUv ³ ry³eBlkñúgvdþrdUv EdlPñasesIms,Úndac;Føak;;Qammk uterine lining breaks down and is expelled out of the body along with eRkAsarBagÁkayCamYynwgGUvulminbgákMenIt. blood and the unfertilized egg. meristem : a plant tissue made of unspecialized rapidly dividing emCalika ³ CalikarukçCatibgáeLIgedayekasikaminbMElgÉkeTs cells. EdleFIVcMEnky:agrh½s. merozygote : A partially diploid bacterial cell containing, a emr:UsuIkUt ³ Epñkekasika)ak;etrIDIbøÚGuIt EdlmanpÞúknUvGgát;RkUm:UsUm chromosome fragment introduced (transformation ) into the cell by transformation, bBa©ÚleTAkñúgekasikaedaykarbMElg kardwkCBa¢Ún transduction, or conjugation, in (transduction ) b¤CMnab;bþÚr (conjugation ) bEnßmeTAelIRkUm:UsUmrbs; addition to its own chromosome. vapÞal;. mesenchyme : a jelly-like material underneath the epidermis of a emsg;sIum ³ sarFatuGn§ilenACab;BIeRkameGBIEDmrbs;eGb:ug. sponge.

mesenteries : Connective tissues that hold the organs in place and PñaseBaHevon ³ Calikasn§anEdlcgP¢ab;srIragÁkñúgeBaHeGayenAnwg also serve as support for blood vessels connecting the various tamkEnøgnigmanmuxgarRTRTg;srésQamEdlP¢ab;BIsrIragÁmYyeTA organs. srIragÁmYyeTotpgEdr. meso compound : Compound with chiral centers that is nonchiral smasFatuemsU ³ smasFatuEdlmanmNÐlKIr:al; EtminEmnCaKIr:al; because of molecular symmetry. edaymkBIm:UelKulsIuemRTI. mesoblast : Mesodermal cell. emsU)aøs ³ ekasikaemsUEDm. mesocarp : The middle layer (often fleshy) of simple fleshy emsUkab rWsac; ³ RsTab;kNþal ¬PaKeRcInsMbUrsac; ¦énEpøsac; fruits; the mesocarp occurs between the exocarp, and the Fmµta. vaenAcenøaHsMbk¬GiucsUkab¦nigbNþÚl¬Gg;dUkab¦. endocarp. mesoderm : The middle layer of cells in an embryo that gives rise to emsUEDm ³ RsTab;ekasikakNþalrbs;GMRb‘Íy:ug EdlvivtþeTACaCalika certain tissues and organs of the adult, including the muscles and nigsrIragÁmYycMnYnrbs;stVeBjv½y rYmmansac;dMu nigRbeBjePT. gonads. mesoglea : A jelly-like material separating the two cell layers in a emsUeKø ³ sarFatuGn§ilenAcenøaHRsTab;ekasikaBIrCan;cMeBaH coelenterate. sWLg;eter. mesophyll : Internal tissue of leaves not including the vascular emsUPIl ³ Calikakñúgrbs;søwk edayminrab;bBa©Úl)ac;srésnaMeT bundles, made of chlerenchyma cells that contain chloroplasts. EdlekIteLIgBIekasikaekør:g;sIumEdlmankør:U)aøs. vamanlMhGnþr There are many intercellular ekasikaCaeRcIn. emIlTMBr½ 330 . spaces. See p. 330. mesophyte : A plant that requires a relatively humid atmosphere and emsUPIt ³ rukçCatiEdlRtUvkarbriyakasesImxøaMg nigdIEdlsMbUr abundant soil water. Compare xerophyte, hydrophyte xerophyte, hydrophyte. Twk. eRbobeFobCamYy . messenger RNA (mRNA) : A ARN ARNm ARN type of RNA that carries the naMsar b¤ ³ RbePTmYyén EdldwknaMBt’mansMrab; instructions for protein synthesis ADN from the DNA to the ribosome sMeyaKRbUetGIunBI eTArIbUsUm EdledIrtYeFVICaBum

metabolism : A group of processes that includes nutrition, production emtabUlIs ³ lMnaMnanaEdlrYmmankarciBa©wm karplitfamBl ¬dM of energy (respiration), and synthesis of more protoplasm; the NkdegðIm ¦nigkarsMeyaKRbUtU)øasEfmeTot. karKYbpSMéndMeNIrkar sum of the constructive sMeyaK ¬ smaNkmµ ¦ nigdMeNIrkarbMEbk ¬ GsmaNkmµ ¦ kñúg (anabolism) and destructive (catab- olism) processes in organisms that sarBagÁkayEdlrYmKñaedIm,IRTRTg;CIvit. collectively sustain life. metacarpal : Small bones in the middle of the hand. See q¥wg)atéd ³ q¥wgtUc²EdlenAkNaþlRbGb;éd. pentadactyl limb, and p. 321. sUmemIl pentadactyl limb nigTMBr½ 321 . metacentric chromosome : A chromosome with a centrally RkUm:UsUmemtasg;RTic ³ RkUm:UsUmEdlmanTItaMgsg;RtUEmenA located centromere, producing chromosome arms of equal lengths. cMkNaþlEdlbegáItCaédRkUm:UsUmRbEvgesµIKña. metafemale : In Drosophila, a poorly developed female of low emtahVIem:l ³ cMeBaHRdUsUPIl CastVjIlUtlas;minl¥ viability in which the ratio of X X chromosomes to sets of autosomes EdllT§PaBrs;Tab edaysmamaRtRkUm:UsUm eTAnwgRkumGUtUsUmelIs exceeds 1.0. Previously called a 1/ 0 . BImuneKehAfa :s‘ubP½rhVIEml }. superfemale. metallic bonding : Type of chemical bond in which atoms karcgsm<½n§elah ³ ³ RbePTsm<½n§KImIEdlGatUmCaeRcIndak;eTVta share electrons by each contributing to a sea of mobile eGLicRtugrYm edaykarpþl;eGLicRtúgnimYy²CamYynwgRkumeGLicRtug electrons that surround all of the Edlcl½tCMuvijGatUm. lkçN³enHnaMeGayelah³GaccMlg crnþGKiÁsnI atoms. This property allows metals to conduct electricity when in the enAeBlvasßittkñúgPaBCaGgÁFaturwg. solid state. metalloids : Elements that share the properties of metals and emtaLÚGIut ³ CaFatuEdlmanlkçN³Caelah³nigGelah³. nonmetals. metals : Group of elements that are good electric conductors and are elah ³ ³ RkumFatuEdlCaGñkcMlgcrnþGKÁisnI)anl¥ nigCaFatuEp)an. malleable. metamale : In Drosophila, a poorly developed male of low emtaem:l ³ cMeBaHRdUsUPIl CastVeQµallUtlas;l¥ viability in which the ratio of X X chromosomes to sets of autosomes EdllT§PaBrs;TabkñúgsmamaRtRkUm:UsUm eTAnwgRkumGUtUsUmTabCag is less than 0.5. Previously called a 0>% . BImuneKehAfa : s‘ubP½rem:l }. supermale. metameric : Relating to ancestral segmentation, used in reference to x½NÐCaEpñk² ³ EdlTak;TgeTAnwgkarx½NÐCakg;énbuBVKWsMedAeTAelI serially repeated units along the body axis. ÉktadEdl²Caes‘rItambeNþayG½kS sarBagÁkay. metamerism : Serial repetition of organs and tissues, including the karx½NÐCaEpñk² ³ es‘rIxNнdUc²KñaénsrIragÁnigCalika EdlrYmman body wall, nervous and sensory systems, and musculature. épÞxøÜn RbB½n§RbsaT srIragÁviBaØaN nigsac;dMu. metamorphosis : A series of changes in form during bMErrUb ³ es‘rIénkarpøas;bþÚrTMrg;kñúgry³eBllUtlas;BITMrg;minTan;eBj development of an immature form to an adult. v½yeTAeBjv½y. metanephridium : An organ open to the body cavity through a emtaenRPIDI ³ srIragÁebIktP¢ab;eTARbehagxøÜntamry³bMBg;Edlman ciliated funnel (nephrostome) and (Nephrostome) involved in excretion or in the eramj½r nigcUlrUmkñúgkarbeBa©jecalrWkñúgkartMrUv regulation of water balance or salt tulüPaBTwk rWGMbilkñúgxøÜn. content.

metaphase : The second stage of mitosis during which the chromatid emtapas ³ dMNak;kalTIBIrénmItUs EdlKURkUm:aTIttMerobKñaenApøak pairs align at the cell’s equator. eGkVaT½r. metaphase I : The first metaphase I I I of meiosis; in metaphase 1, pairs of emtapas ³ emtapas éncMENkemy:Us. enAemtapas enH homologous chromosomes align along an equatorial plane that is KURkUm:UsUmGUm:ULÚkmktMerobtambeNþaybøg;eGkVaT½rEdlEkgeTAnwgG½kS perpendicular to the axis of the srésRtyUgGaRkUm:aTic. spindle apparatus. metaphase II : The second II II II metaphase of meiosis; in emtapas ³ emtapas éncMENkemy:Us . enAemtapas enH metaphase II, chromosomes align along an equatorial plane that is RkUm:UsUmtMerobtambeNþaybøg;eGkVaT½rEdlEkgeTAnwgbøg;eGkVaT½r perpendicular to the equator in kñúgemtapas I. metaphase I. metaphase plate : The plane of alignment of chromosomes during pøakeGkVaT½r ³ bøg;tMerobénRkUm:UsUmkñúgvKÁemtapas. vasßitenAEkg metaphase; the metaphase plate is perpendicular to the axis of the eTAnwgG½kSRtyUgGaRkUm:aTic. spindle apparatus. metatarsal : Small bones in the middle of the foot. See q¥wg)ateCIg ³ q¥wgtUc²EdlenAkNþalRbGb;eCIg. pentadactyl limb, and p. 321. sUmemIl pentadactyl limb nigemIlTMBr½ 321 . metaxylem : Primary xylem that differentiates after the protoxylem; emtasuIELm ³ suIELmTImYy EdlbMElgÉkeTsbnÞab;BIRbUtUsuIELm . reaches maturity after the part of the plant in which it is located has emtasIuELmeBjv½ybnÞab;BIEpñkrukçCatiEdlvasßitenAenaH)anQb; stopped elongating. lUtlas;beNþay. metazoan : A multicellular animal. protozoa Compare protozoa. emtasUEG ‘r ³ stVBhuekasika. eRbobeFobCamYy . meter , metre : (m) Basic unit of SI length in the metric and SI Em:t ³ ÉktaRKwHénRbEvgCaEm:t nigCargVas;tamRbB½n§GnþrCati ¬ ¦. measurement systems. 1m = 100cm. 1m= 100s m. methane : A compound made of a carbon atom covalently bonded to emtan ³ smasFatubgáeLIgedayGatUmkabUnmYy P¢ab;eTAnwgGatUm four hydrogen atoms. GIuRdUEsnbYnedaysm<½n§kUva:Lg;. methanol : An alcohol having the ³ Gal;kulEdlmanrUbmnþ CH 30H . formula CH 30H. emtaNul metric system : French measurement system from which RbB½n§Em:t ³ RbB½n§rgVas;)araMg EdlvivtþCaRbBn½§xñatGnþrCati. evolved the System Internationale d’Unites (SI). The metric system RbB½n§CaEm:tCaRbB½n§rgVas;dMbUgeKbg¥s; EdleRbIEpndICasþg;da. was the first measurement system to use the earth as a standard. MHC : Major histocompatibility MHC loci. In humans, the HLA complex; ³ PaBsmRsbsMxan;kñúgkarpSMFatuLÚKus. cMeBaHmnusSKWkMpiøc and in mice, the H2 complex. HLA nigcMeBaHstVkNþúrKWkMpøic H2. micelle : A group of hydrocarbon molecules having polar ends in the mIEsl ³ m:UelKulGIuRdÚkabYmYyRkumEdlmancugb:UElrenAkñúgRsTab;Twk. water phase.

microbody : A vesicle-like organelle that is bounded by a GgÁtUc ³ FatuekasikaragdUcfg; EdlmanPñasB½T§CMuvijmYyCan; single membrane and is generally associated with the endoplasmic ehIyCaTUeTAmanTMnak;TMngeTAnwgerTIKuyLÚmGg;dU)aøs. KøIGUsuIsUm reticulum; glyoxysomes and (glyoxysomes) nigeBrU:suIsUm (peroxisomes) KWCaRbePTGgÁtUc. peroxisomes are types of microbodies. microevolution : Evolutionary changes that occur within a mIRkUvivtþn_ ³ karpøas;bþÚrvivtþn_EdlekItmaneLIgenAkñúgb:UBuyLasüúg. population; may eventually lead to the formation of a new species, but vaGacQaneTArkkarbegáItRbePTfµImYy b:uEnþminEmnekIteLIgenAeBlCa not as a one-time event. mYyKñaenaHeT. microfibril : A complex of cellulose molecules that are twisted mIRkUPIb ³ kMepøcm:UelKulEsluyLÚsEdlRtUv)anevjRbTak;cUlKña together into a strong, threadlike component of cell walls. eTACaFaturagdUcExSd¾maMmYyrbs;PñaseRKag. microfilaments : Long, fiber-like structures made of protein and mIRkÚPILam:g; ³ TMrg;srésEvg² bgáeLIgedayRbUetGIunEdlmanenAkñúg found in cells, often in close association with microtubules; ekasika nigeRcInEtpSMCamYykUnbMBg;edIm,IRTRTg;TMrg;nigeFIVeGayman provide structural support and clna. enable movement. microhabitat : The particular part of a habitat occupied by an mIRkUlMenA ³ kEnøgrs;enAedayELkEdlkan;kab;edayÉktþ³mYy. individual. micrometer : A unit of length 1 X 10 –6 1/1000 equal to 1 X 10 –6 meter or 1/1000 mIRkUEm:t ³ CaxñatRbEvgmYy esñInwg Em:t rW mIlIEm:t. of a millimeter. Previously called a BImuneKehAfamIRkug EdlmanGkSrkat; µm . micron. Abbreviated µm. micron : See micrometer. mIRkug ³emIl micrometer . micronucleus : An organelle in paramecia that contains the mIRkÚéNVy:U ³ Fatuekasikaén)a:r:aemsIu EdlmanpÞúkRkUm:UsUm. chromosomes. micronutrients : Inorganic elements required in small amounts mIRkUFatuciBa©wm ³ sarFatuGsrIragÁ EdlRtUvkarkñúgbrimaNtictYc for plant growth (e.g., boron, B, Cu Zn copper, zinc). sMrab;karlUtlas;rbs;rukçCati ¬]TahrN¾³ nig ¦. microorganism : A microscopic living thing. mIRkÚsarBagÁkay ³ Pavrs;tUc²EdlemIleXIjedaymIRkUTsSn_. micropyle : A small opening in the ovule wall through which the mIRkÚBIl rWTVarRKab;RkeBj ³ rn§tUcénPñasGUvulsMrab;bMBg;lMGgcUl. pollen tube enters. microscope : A device that provides an enlarged image of mIRkÚTsSn_ ³ ]bkrN_EdleFVIeGayvtßútUc² køayeTACarUbPaBFM². small objects. microsome : A part of the ARN cytoplasm containing RNA and is mIRkÚsUm ³ EpñkmYyénsuItU)øasEdlman nigCakEnøgsMeyaK the site of protein synthesis. RbUetGuIn. microsphere : A collection of organic macromolecules in a mIRkÚEs‘V ³ TMrg;m:aRkUm:UelKulsrIragÁenAkñúgTMrg;mYyEdlmanPñasxag structure with a double-layered outer boundary. eRkABIrCan;. microsporangium : A male reproductive structure of the mIRkÚs,:r:g; ³ TMrg;bnþBUCeQµalrbs;rukçCatiBBYkRsl;EdlbegáItmIRkUs,: conifers that produces haploid microspores. GabøÚGIut.

microspore : A haploid cell giving rise to the male gametophyte or mIRkÚs,: ³ ekasikaGabøÚGIutEdllUtlas;eTACakaEm:tUPIteQµal b¤RKab; pollen grain in gymnosperms and angiosperms. lMGgcMeBaHsIumNUEsl¦ ³ ÉktamaDEdleRbIkñúgviTüasaRsþ nigevC¢saRsþeday medicine because of its convenient small size equal to 1/1000 L. sarEtTMhMtUcsmRsbrbs;vaEdlesµInwg 1/1000 l. millimeter(mm) : Metric unit of length equal to 1/1000 m (the mIlIEm:t¬m>m¦ ³ xñatRbEvgCaEm:tesIµnwg 1/1000m ¬buBVbT decimal prefix milli- means times 1/1000). CaTsPaKEdlmIlIø-mann½yfaKuNnwg 1/1000. milt : A sperm-containing fluid made by the testes in fish. TwkkamRtI ³ sarFaturavmanEs

minimal medium : A medium containing only those nutrients that mCÄdæanciBaVwmGb,brma ³ mCÄdæanciBaVwmEdlmanEtsarFatuciBa©wm will support the growth and reproduction of wild-type strains of sMrab;RTRTg;karlUtlas;nigkarbnþBUCénBUCéRBrbs;Pavrs;b:ueNaÑH. an organism. missense mutation : A mutation in which one base pair is altered muytasüúgmIesn ³ muytasüúgEdlmankarpøas;bþÚrKU)asmYy ehIy causing an amino acid change in the protein product of the gene. bNþaleGaymankarpøas;bþÚrGasIutGamIenenAkñúgplitplRbUetGIunénEsn enaH. mitochondrial DNA : The DNA ADN ADN genome in the mitochondrion that mItUkugRDI ³ esNUm kñúgmItUkugRDIEdlmanRkmsMrab; codes for many of the ADN mitochondrion’s functions. muxgarCaeRcInrbs;mItUkugRDI. mItUkugRDIRtUv)ansV½ydMeLIgeTV nig mtDNA is replicated and cMlgRkmedayRkumGg;suImepSgBIRkumGg;suImkúñgéNVy:UGWkarIy:Ut. transcribed by a separate set of enzymes from those of the eukaryotic nucleus. mitochondrion (plural mitochondria) : An organelle in mItUkugRDI ³ FatuekasikasßitenAkñúgsIutU)øas;rbs;ekasikaGWkarIy:Ut Edl the cytoplasm of eucaryotic cells in which energy production, the karplitfamBl vdþERkb nigGuksIutkmµpUsVrekItman. mItUkugRDIman Kreb’s cycle and oxidative ADN nigeFVIkarsV½ydMeLIgeTVedayxøÜnÉg. phosphorylation occurs. They contain DNA and are self- replicating. mitogen : A substance that stimulates mitosis in non-dividing mItUEsn ³ CasarFatuePa£cmItUskñúgeBlekasikamineFVIcMENk. cells; e.g., phytohemagglutinin. ]TahrN_³ sarFatu phytohemagglutinin . mitosis : A type of nuclear division which produces two daughter cells mItUs ³ RbePTmYyéncMEnkéNVyU:EdlbegáItekasikakUnBIrEdlmancMnUn with the same number of chromosomes as the parent cell. RkUmU:sUmdUceTAnwgRkUmU:sUmrbs;ekasikaem)a. vamanbYnvKÁsMxan;² KW There are four main stages, RbUpas emtapas GaNapas nigetLÚpas. prophase, metaphase, anaphase, teleophase. mixture : Material that has no set proportion of its component l,ay ³ rUbFatuEdlKµansmamaRtsmasPaKénsarFaturbs;va nigGac substances and can be separated into its components relatively RtÚv)anEjkecjCasmasPaKrbs;edaygayEdlsarFatunImYy²enA easily and where each substance EtrkSalkçN³edImdEdl. retains its own characteristics. mode : The value occurring in the greatest frequency in a set of data. m:Ut ³ tMélEdlekIteLIgedayeRbkg;FMbMputkñúgRkumTinñn½ymYy. moderator : Material that slows neutrons. Slow neutrons are more m:Uedr:aT½r ³ sarFatuEdlBnüWtel,ÓnNWRtúg. éNVy:UMEbkcab;yk readily captured by fissionable nuclei than are fast neutrons. NWRtugyWt)angayCagNWRtúgelOn. molar : A large flat tooth used for grinding. eFµjfÁam ³ eFµjEdlmanragsMEb:tFM sMrab;TMBarGahar. molarity (m) : Concentration of a solution in moles of solute per liter m:ULarIet ³ kMhab;sUluysüúgCam:UlénFaturlaykñúgsUluysüúg of solution. The preferred unit of concentration in chemistry. mYylIRt. ÉktaénkMhab;EdleKcUlcitþeRbIkñúgKImI. mold : See mould. pSitp¥Ür ³ emIl mould .

mole (mol) : 6.023 X 10 23 atoms or 6.023 X 10 23 molecules. One mole of a m:Ul ³ GatUmb¤m:UelKul. sarFatumYymU:lmanma:sKitCa substance has the same mass in grams as its atomic or molecular RkamdUcKñanwgm:asGatUmicb¤ma:smU:elKulrbs;vakñúgÉktama:sGatUmic. mass in atomic mass units. eg. 1 ]TahrN_ ³ GuksuIEsn1mU:l= 32Rkam. mole 0 2 = 32g. mole method : Use of the mole concept to calculate masses of viFIm:Ul ³ kareRbIR)as;c,ab;m:UledIm,IKNnam:asGgÁFatuRbtikr nig reactants and products involved in chemical reactions. GgÁFatukekItenAkñúgRbtikmµKImI. molecular collision theory : Idea that for a chemical reaction to RTwsþITgÁicm:UelKul ³ KMnitEdlfaedIm,IRbtikmµKImIekIteLIg eday occur, molecules must (a) collide a b and (b) collide with sufficient m:UelKulRtÚvEt ¬ ¦TgÁicKña nig ¬ ¦TgÁicKñaCamYyfamBlRKb;RKan; energy to break chemical bonds. edIm,Ipþac;sm½

monoecious : Characterized by the presence of both sexes in a single rYmePT ³ EdlsMKal;edayvtþmanénePTTaMgBIrenAelIÉktþ³EtmYy ¬bnþ individual, either in sequence or sequentially; having the bnÞab;Kña rWrYmKña ¦ EdlmansrIragÁplitRKab;lMGgnigGUvulenAelIÉktþ³Et pollen-producing and the mYy KWrUmePT. ovule-producing organs on the same individuals; hermaphroditic. monohybrid cross : A genetic cross involving only one pair of karbgáat;mU:NUGIuRb‘Ít ³ karbgáat;esenTic EdlmanGaELlEtmYyKU. alleles. monokaryotic : Fungi whose cells each contain a single nucleus m:UNUkarIy:Ut ³ pSitEdlekasikanimYy²manéNVy:UEtmYy. monomer : Smallest repeating unit from which polymers are made. m:UNUEm ³ ÉktatUcbMputdEdl²EdlbgáCab:UlIEm. monophyletic : Groups that contain an ancestor and all the m:UNUPIelTic ³ RkumEdlmanbuBVmYynigkUnecACMnan;eRkayTaMgGs; descendants of that ancestor. rbs;buBVenaH. monophyly : Relationship of two or more taxa having a common m:UNUPIlI ³ TMnak;TMngrvagBUCGMbUrBIr rWeRcInEdlmanbuBVrYm. ancestor. monosaccharide : A simple sugar that cannot be decomposed into m:UNUsakarIt ³ sársamBaØEdlminGacbMEbkeTACam:UelKulsártUcCag smaller sugar molecules; contains five to six carbons such as glucose. )aneT. mU:elKulEdlmankabUnR)aMeTAR)aMmYydUcCaKøúykUs. vaCa These are the basic units from ÉktaRKwHEdlbegáItkabUGIuRdatFM². which larger carbohydrates are made. monosomy : Missing a Turner’s syndrome chromosome. eg. Turner’s m:UNUsUmI ³ kar)at;RkUm:UsUmmYy. ]- . syndrome. monoterpene : A compound that consists of two isoprene units m:UNUETEBn ³ smasFatuEdlekIteLIgBIÉktaGuIsUERbnBIrCab;Kña linked together; menthol is an example monoterpene. ¬]>m:g;tul ¦. monotreme : An egg-laying New mammal. Only found in Australia mU:NUERtm ³ fnikstVBgEdlmanEtenARbeTsGU®sþalI nig and New Guinea. eg. platypus. Guinea . ]TahrN_ ³ platypus . monozygotic twins : Twins produced from a single fertilization kUnePøaHBit ¬b¤kUnePøaHdUcKña¦ ³ kUnePøaHEdlekItecjBIkarbgákMenIt event; the first division of the zygote produces two cells, which EtmYy cMEnkdMbUgénsuIkUtEdlbegáItCaekasikaBIrEdllUtlas;eTACa develop separately into two GMRb‘Íy:ugBIrdac;edayELkBIKña. embryos. Also known as identical twins. morph : Genetically determined variant in a population. m:hV ³ Éktþ³bMErbMrYlenAkñúgÉktþ³BYkRkum EdlRtUv)ankMNt;tam lkçN³esenTic. morphogenesis : Development of the architectural features of kMNrag ³ karlUtlas;énlkçN³rUbragrbs;sarBagÁkay . organisms. morphological plasticity : Condition in which environmental karERbRbYlrUbrag ³ l½k½çNÐçdlktþabrisßaneFVIeGaymanepNUTIbepSg factors induce different phenotypes from the same genotype. KñaecjBIesNUTIbEtmYy.

morphology : The science of structure. Includes cytology, or the ragviTüa ³ viTüasaRsþénTMrg;EdlrYmmanekasikaviTüa rWkarsikSaBITMrg; study of cell structure; , or the study of tissue structure; and ekasika CalikaviTüa rWkarsikSaTMrg;Calika nigkayviPaKviTüa rWkarsikSaBI anatomy, or the study of gross TMrg;TUeTA. structure. morphotypic : Type of classification based entirely on m:hVÚTIBic ³ RbePTcMENkfñak;EdlEp¥kelIlkçN³rUbragxageRkA physical form. TaMgRsug. mortality : The number of individuals leaving the population GRtasøab; ³ cMnYnÉktþ³Edlsøab;kñúg1000Éktþ³énb:UBuyLasüúg. by death per thousand, individuals in the population. mosses : Lower plants that have a dominant gametophyte, generation, Esø ³ rukçCatifñak;Tab EdlmanCMnan;kaEm:tUPItlub mans,:nig spores, and swimming sperm. They lack vascular tissue. Es

multiple alleles : Having three or more alternate genes that can code GaELleRcIn ³ manEsnbIrWeRcInCagbIEdlGaccMlgRkmsMrab;lkçN³ for a trait. mYy. multiple fruit : A type of fruit that develops from a single ovary of EpøeRcIn ³ RbePTEpøEdllUtlas;BIGUEveTalrbs;páanImYy²kñúgcegáam . each flower in a cluster. eg. Pineapple, mulberry. ]TahrN_³ Epømñas; Epømn. multiple infection : Simultaneous infection of a bacterial cell by more BhueRCótcUl ³ CakareRCótcUlrbs;)ak;etrIy:UpasdMNalKñaCaeRcIn than one bacteriophage, often of different genotypes. cUleTAkñúg)ak;etrI CajwkjymanesNUTIbxus²Kña. multiple-factor inheritance : See polygenic inheritance polygenic inheritance. tMnBUCktþaBhuKuN ³ emIl . murein : A nitrogen-containing polysaccharide making the cell muyerGIun ³ b:UlIsakarItEdlmanGasUt EdlbegáItPñaseRKagrbs; wall in monerans. m:Uenr:a. muscle tissue : A specialized group of contractile cells Calikasac;duM ³ RkumekasikakRnþak;Edlmanmuxgarr:ab;rgclna . responsible for movement. There are three main types of muscle in mansac;dMubIRbePTsMxan;² cMeBaHstVq¥wgkg KWsac;dMuqñÚt sac;dMurelag vertebrates- striated, smooth and nigsac;dMuebHdUg. emIl myofibril, myosin, tropomyosin, actin, cardiac . See also myofibril, myosin, tropomyosin, actin, sarcomere, I-band, antagonistic pair nigemIlTMBr½ 325 . sarcomere, I-band, antagonistic pair, and p. 325. mutagen : Any agent that can increase the rate of mutations. muytaEsn ³ Pñak;garNaEdlGacbegáInGRtamuytasüúg. mutant : A cell or organism carrying an altered or mutant gene. muytg; ³ ekasikab¤srIragÁEdlpÞúkEsnERbRbYlb¤Esnmuytg;. mutarotation : Change in specific rotation seen in sugar solutions that muytar:Utasüúg ³ karERbRbÜlénrgVilyfaRbePTkñúgsUluysüúgsár results from equilibrium between anomeric forms. EdlbNþalmkBIlMnwgrvagsNæanGaNUEm. mutation : Damage to the genetic mechanism of a cell, causing it to muytasüúg ³ karb:HBal;dl;clnkaresenTicénekasika Edl reproduce in a different form. A permanent change in the base bNþaleGaykarbnþBUCekItmankñúgTMrg;epSg². bMErbMrYlCanirnþr_kñúg sequence of DNA that changes tMNlMdab;)asrbs;GasIutedGuksIurIbUnuyekøGiuceFIVeGaymankarERbRbÜl genetic information. Bt’manesenTic. mutation rate : The frequency with which mutations take place at GRtamuytasüúg ³ CaeRbkg;EdlmuytasüúgekIteLIgelILÚKus a given locus or in a population. NamYy b¤kñúgb:UBuyLasüúgmYy. muton : The smallest unit of mutation in a gene, corresponding muytug ³ ÉktatUcbMputénmuytasüúgkñúgEsnmYy EdlRtUvKñaeTAnwg to a single base change. karbþÚr)asmYy. mutualism (symbiosis) : A symbiotic relationship that is shR)aN ³ TMnak;TMngshR)aN EdlPavrs;TaMgBIrTTYlpl beneficial to both organisms. TaMgGs;Kña. ]- lIEkn. mycelium : A network of filamentous hyphae in fungi. mIeslüÚm ³ bNþajsrésGIuhVrbs;pSit. mycolaminarin : A carbohydrate food reserve of water molds mIkULamINarIn ³ GaharbMrugkabUGIuRdatrbs;pSitTwk ¬GUGUmIEst ¦. (oomycetes).

mycorrhiza : A symbiotic relation between fungi and plant mIkUrIs ³ TMnak;TMngshR)aNrvagpSitnigrwsrukçCati. roots. mycotoxin : A deadly poison produced by fungi. CatiBulpSit ³ CatiBulbNþaleGaysøab; EdlplitedaypSit. myofibril : A contractile filament within muscle or muscular fiber. kUnPIbsac;dMu ³ sréskRnþak;enAkñúgsac;duM b¤PIbsac;duM. See p. 325. emIlTMBr½ 325 . myosin : The protein making up the thick filaments in a muscle mIyU:sIun ³ RbUetGIunEdlbegáItPILam:g;Rkas;²kñúgkUnPIbsac;duM. myofibril. See p. 325. emIlTMBr½ 325 . myxedema : A disease that results from thyroid deficiency in the ehIm ³ Cm¶WEdlbNþalBIkgVHTIr:UGIutcMeBaHmnusSeBjv½yEdl adult; characterized by swellings under the skin. sMKal;edaykarehImTUeTA. myxobacteria : A group of complex, gram-negative soil mIsU)ak;etrI ³ Rkum)ak;etrIRkamGviC¢mansaMuBaJauMrs;enAkñúgdIEdleRcInEt bacteria that often form upright, multicellular, reproductive bodies. begáItsrIragÁbnþBUCBhuekasika)as;eLIgeTAelI. N NAD (nicotinamide adenine NAD : dinucleotide) : A coenzyme that kUGg;sIumEdlmanmuxgarCaGñkTTYlGIuRdUEsnkñúgdegðImekasika. acts as a hydrogen acceptor in cellular respiration. NADH dehydrogenase complex : NADH A complex of enzymes whose kMuepøc edGIuRdUEsnNas ³ kuMpøicGg;sIumEdlmantYnaTI function is to transport protons NADH from NADH across the inner dwknaMRbUtugBI kat;tamPñaskñúgrbs;mItUkugRDI. mitochondrial membrane. NADP (nicotinamide adenine NADP : dinucleotide phosphate) : A kUGg;sIumEdlmanmuxgarCaGñkTTYlGIuRdUEsnkñúgrsµIsMeyaK. coenzyme that acts as a hydrogen acceptor in photosynthesis. nanometer : A unit of length equal 1 X 10 -9 nm to 1 X 10 -9 meter. Abbreviated nm. NaNUEm:t ³ xñatRbEvgesµInwg Em:t nigmanGkSrkat; . narcotic : A pain-killing drug. NakUTic ³ fñaMbM)at;karQWcab;. nares : Nostrils. rn§RcmuH nastic movement : A plant response that is independent of the clnaNasÞIc ³ cMelIytbrbs;rukçCati EdlminGaRs½yeTAelITis stimulus direction but is a reversible result of turgor pressure énrMejac b:uEnþmanlT§plRtlb;mkvijedaykarERbRbYlsMBaFe)a:g. changes. natality: The number of individuals entering the population GRtaekIt ³ cMnYnÉktþ³EdlcUlmkkñúgb:UBuyLasüúgtamry³karbnþBUC by reproduction per thousand individuals in the population. kñúg1000Éktþ³énb:UBuyLasüúgenaH. native conformation : Normal shape or conformation that a kugpm:asüúgedIm ³ RTg;RTayFmµtab¤kugpm:asüúg EdlRbÚetGIunsßitenA protein has in its biological setting performing its normal biological kñúgTItaMgCIvsaRsþ nigdMeNIrkarskmµPaBCIvsaRsþrbs;va. activity.

natural radioactivity : Spontaneous emission of nuclear viTüúskmµPaBFmµCati ³ karbeBa©jPaKli¥ténéNVy:UnigkareRcotcUl particles and penetrating radiation by naturally occurring unstable énrsµIedayÉkÉgedaymankarkekItGatUmKµansßirPaBkñúgFmµCati. atoms. The radioactive atoms are GatUmviTüúskmµTaMgLayRtÚv)anbMElgeTACaFatuKImIfµIkñúglMnaMenH. changed to new elements during the process. natural selection, theory of : In a species of genetically different RTwsþICMerIsedayFmµCati ³ cMeBaHRbePTmYyénPavrs;EdlmanesenTic organisms, the organisms with the genes that enable them to survive xusKña Pavrs;EdlmanEsnGaceGayvars;enA)anl¥kñúgbrisßannigbegáIt better in the environment and thus kUnecA)aneRcInCagPavrs;epSgeTot nwgbBa¢ÚnEsnrbs;vaeTAeGayCMnan; reproduce more offspring than others will transmit more of their eRkaykan;EteRcIn. Pavrs;bnSaM)anl¥Gacrs;enAnigbnþBUC. genes to the next generation. Better adapted organisms survive and reproduce. nearest-neighbor analysis : A molecular technique used to karviPaKjatiCit ³ viFIeRbIm:UelKuledIm,IkMnt;eRbkg;Edl determine the frequency with which nucleotides are adjacent to nuyekøGUTItRtUvP¢ab;KñaeTAvijeTAmkkñúgRcvak;b:UlInuyekøGUTIt. each other in polynucleotide chains. nectar : A sugary fluid produced by many flowers to attract Twkdmpáa ³ vtßúravmanCatisár EdlplitedayrukçCatiCaeRcInedIm,ITak; pollinators. TajstVraylMGg. nectary : A structure in angiosperms that secretes nectar; srIragÁbeBa©jTwkdm ³ TMrg;énrukçCatiGg;süÚEs

neoteny : Retention of larval or embryonic characteristics past the enGUetnI ³ karrkSalkçN³CakUnjas; rWGMRb‘Íyu:grhUtdl;hYsv½y time of reproductive maturity. See paedomorphosis and progenesis also paedomorphosis and bnþBUC. emIl . progenesis. nephridium : An excretory structure in segmented worms. enRhVIDI ³ TMrg;beBa©jecalrbs;dgáÚvxøÚnkg;. nephron : A tiny excretory unit of the kidney that filters urine from enRhVúg ³ ÉktabeBa©jecaltUc²rbs;tMrgenamEdleRcaHTwkenam the blood. BIQam. nerve : A bundle of neuron fibers. srésRbsaT ³ )ac;srésekasikaRbsaT. nerve cell : See neuron . ekasikaRbsaT ³ emIl neuron . nerve impulse : A message conducted along the axon of a crnþRbsaT ³ sarEdlekIteLIgtambeNþayGak;sUnénekasikaRbsaT nerve, in the form of a wave of reversing polarity at the nerve cell kñúgTMrg;Carlkénkarqøas;b:UlKñaenAelIPñasekasikaRbsaT. membrane. nerve tissue : A specialized group of cells capable of conducting CalikaRbsaT ³ RkumekasikaÉkeTs EdlGacdwknaMcrnþrMejacnig electrical impulses and forming the communication system of the begáItRbB½n§TMnak;TMngkñúgsarBagÁkay. body. nervous system : A network of neurons that carry information RbB½n§RbsaT ³ bNþajekasikaRbsaT EdldwknaMBt’manBIsrIragÁ from sense organs to the central nervous system and, from the viBaØaNeTARbB½n§mCÄmNÐlRbsaT nigBIRbB½n§mCÆmNÐlRbsaTeTA central nervous system to muscles sac;dMunigRkeBj. emIl autonomic nervous system,sympathetic and glands. See autonomic nervous system, sympathetic nervous system, parasympathetic nervous sustem . nervous system, parasympathetic nervous system. net ionic equation : Chemical equation describing an ionic smIkarGIuy:UnicsMrYl ³ smIkarKImIerobrab;BIRbtikmµGIuy:Unic EdlRtÚv)an reaction that is written to identify those ions that leave the reaction sresredIm,IbgðajBIGIuy:ugTaMgenaHEdlpþac;ecjBIRbtikmµtamry³karkkr via precipitation, formation of a karkekItCa]sµ½n b¤karkekItCasarFatukUv:aLg;GRbtikmµ . gas, or formation of nonreactive covalent substance. net movement : The movement in one direction minus the clnasuT § ³ clnamYyTisdkclnaTispÞúynwgva. ]TahrN_³ movement in the opposite direction. e.g. particles diffuse in bMENktUc²sayPayRKb;TisedA b:uEnþclnasuT§ekItmanenAq¶ayBI all directions, but net movement kEnøgEdlbMENktUc²enaHmankMhab;xøaMgeTAdl;kEnøgEdlvaman occurs away from where particles are most concentrated to where kMhab;exSay. they are least concentrated. net productivity : The energy produced in an ecosystem by plitplBit ³ famBlEdlbegáIteLIgenAkúñgRbB½n§eGkULÚsIueday photosynthesis minus the energy lost through respiration. rsµIsMeyaKdknwgfamBlEdl)at;bg;tamry³dMNkdegðIm. neural arch : Arch on the dorsal surface of vertabra for the passage FñÚsnøak;q¥wgxñg ³ FñÚEpñkxagxñgénq¥wgxñgkNþalrbs;stVq¥wgkgsMrab; of the spinal cors. srésRbsaTecjBIxYrq¥wgxñg.

neural crest : Embryonic cells unique to vertebrate animals, EKmRbsaT ³ CYrekasikaGMRb‘Íyu:gEdlmanEtstVq¥wgkg EdlsßitenACa associated with the neurectoderm but subsequently widely migrating mYyGictUEDmRbsaT b:uEnþbnÞab;mkvapøas;kEnøgeTAcUlrYmkarbegáItCalika to participate in the nigTMrg;CaeRcInEdlCalkçN³rbs;saxargenH. formation of many tissues and structures which are characteristic of the subphylum. neurocranium : Portion of the head skeleton encasing the brain. llad¾k,al ³ EpñkeRKagq¥wgk,alEdleRsabxYrk,al. neuron : A nerve cell specialised for the transmission of electrical NWr:Un ³ ekasikaRbsaTÉleTssMrab;karbBa¢ÚnbnÞúkGKÁisnI. charges. It usually consists of a cell body containing a nucleus, an axon CaTUeTAvaekIteLIgBItYrekasikaEdlpÞúkéNVyU: manGak;sUnnigdg;RDIt. and dendrites. neurotoxin : A substance that interferes with the normal NWr:UntuksIun ³ sarFatuEdlrMxandMenIrkarFmµtarbs;ekasikaRbsaT. functioning of neurons. neurotransmitter : A chemical that transmits impulses across a GñkbBa¢ÚnsarRbsaT ³ FatuKImIEdlbBa¢ÚnrMejacqøgkat;sIuNab;. synapse. neutral : The state of being electrically balanced. NWt ³ sPaBEdlbnÞúkGKÁIsnImanlMnwg. : A mutation with no immediate adaptive muytasüúgNWt ³ muytasüúgEdlKµansar³sMxan;sMrbtMrUvPøam² b¤ significance or phenotypic effect. Kµan\T§iBlepNUTIbeT. neutralization : A chemical reaction in an acid is mixed with a NWtkmµ ³ RbtikmµKImIekIteLIgBIkarpSMKñarvagGasIutnig)as Edl)an base. A salt and water are produced. GMbilnigTwk. neutron : An uncharged particle found in the nucleus of an atom NWRtug ³ PaKl¥itEdlKµanbnÞúk sßitenAkñúgéNVy:Urbs;GatUm Edlman with a mass of 1 amu. m:as 1 amu . neutrophil : A type of granulocyte white blood cell NWRtUPIl ³ RbePTRkanuyLÚsIuténeKalikaQams EdlCaeKalika (leucocyte) which is the most common leucocyte. They are sEdlmaneRcInCageKbMput. vaCapakUsIutnigCYykMcat;karbgáCMgWBI phagocytic and help to fight )ak;etrI. bacterial infections. niche : The way an organism interacts with the biotic and abiotic viFIrs ; ³ rebobEdlPavrs;eFIVGnþrGMeBICamYyktþamanCIvit b¤ktþaKµanCIvit factors of the environment. It is characteristic for one species. énbrisßan. vaCalkçN³BiesssMrab;RbePTmYy. nicotinamide adenine dinucleotide (NAD +/NADH) : nIkUTINamItGaednInDInuyekøGUTIt ³ nuyekøGUTItEdleFVICaGñk Nucleotide that serves as an (NAD +) (NADH) acceptor (NAD +) and donor TTYl nigCaGñkpþl; eGLicRtúgenAkñúgRbtikmµekasika. (NADH) of electrons in cellular reactions. nicotinamide adenine dinucleotide phosphate nIkUTINamItGaednInDInuyekøGUTItpUsVat ³ kUGg;sIumTak;TgeTAnwg (NADPH) : Coenzyme involved in reduction reactions in anabolism. RbtikmµerdukmµkñúgGaNabUlIs. nicotine : A drug found in tobacco. nIkUTIn ³ CatifaMñenAkñúgfñaMCk;.

nictitating membrane : The third eye lid of some vertebrates. It is a RtbkEPñkTIbI ³ RtbkEPñkTIbIrbs;stVq¥wgkgmYycMnYn. vaKWCaPñas- thin transparent covering over the eye that protects it and keeps it esþIgqøúHRKbBIelIEPñkEdlkarBarnigeFVIeGayEPñkmanlkçN³esImCanic©. moist. nitrification : The oxidation of ammonium ions or ammonia to nIRtatkmµ ³ dMeNIrGuksIutkmµénGIuy:ug Gam:Uj:Úm b¤Gam:Ujak;eTACa nitrate, by certain freeliving bacteria in the soil. nIRtateday)ak;etrImYycMnYnrs;enAesrIkñúgdI. nitrifying bacteria : Bacteria capable of converting ammonium )ak;etrIP¢ab;GasUt ³ )ak;etrIEdlGacbMElgGIuy:ugGam:Uj:UmeGayeTACa ions into nitrate ions. See Nitrogen- Nitrogen-fixing bacteria fixing bacteria. GIuy:ugnIRtat. emIl . nitrogen fixation : A process in which certain bacteria and karP¢ab;GasUt ³ dMenIrEdl)ak;etrI nigsüaNUPItxøHGacbMElgGasUt cyanophytes can convert atmospheric nitrogen into usable kñúgbriyakaseGayeTACasmasFatuGasUtEdlGaceRbIR)as;)an. nitrogen compounds. nitrogenase : A complex of enzymes that convert atmospheric nIRtUEsnNas ³ kMpøicGg;sIum EdlbþÜrGasUtbriyakaseGayeTA nitrogen gas into ammonia. CaGam:Yjak;. nitrogen-fixing bacteria, free- living : Soil bacteria that convert )ak;etrIP¢ab;GasUtEdlrs;enAedayesrI ³ )ak;etrIenAkñúgdIEdlbMElg nitrogen gas molecules into nitrogen compounds that plants can m:UlelKul]sµ½nGasUteGayeTACasmasFatuGasUtEdlrukçCatiGac use. eRbIR)as;)an. nitrogen-fixing bacteria, symbiotic : Bacteria that live in )ak;etrIP¢ab;GasUtshR)aN ³ )ak;etrIrs;enAkñúgrwsrukçCatimYycMnYn the roots of certain kinds of plants, where they convert nitrogen gas EdlbMElgm:UelKul]sµ½nGasUteGayeTACasmasFatuEdlrukçCatiGac molecules into compounds that eRbIR)as;)an. plants can use. nitrogenous base : A category of organic molecules found as )asGasUt ³ RbePTm:UlelKulsrIragÁEdlCasmasPaKrbs;GasIut components of the nucleic acids. There are five common types: nuyekøGiuc. man)asGasUt5RbePT KW GaednIn kanIn sIutUsIun TImIn thymine, guanine, cytosine, nigG‘uyr:asIul. adenine, and uracil. nocturnal : Related to night time. raRtIcr ³ EdlTak;TgeTAnwgeBlyb;. node : The region of the stem where the leaf attaches. fñMag ³ kEnøgEdlsøwkP¢ab;eTAelIedIm. nodule : A swelling on the roots of some plants. kMBkrws ³ kEnøgBkenAtamrwsrbs;rukçCatimYycMnYn. non-biodegradable (adj) : Not capable of being broken down by minGacbMEbk)antamviFICIv³ ³ EdlminGacbMEbk)anedaydMenIr biological decomposition. bMEbkCIvsaRsþ. noncompetitive inhibitor : Reversible inhibitor that binds to Gñkbg¥ak;minRbECg ³ Gñkbg¥ak;bRBa©s; EdlP¢ab;eTAnwgGg;sIumenA an enzyme at a location other than the active site and thus does not kEnøgepSgBImNÐlskmµ nigminRbECgCamYys‘ubRsþaeT. compete with the substrate. noncrossover gamete : A gamete which contains no chromosomes kaEm:tKµancMlas;Esn ³ kaEm:tEdlKµanpÞúkRkUm:UsUmEdl)an that have undergone genetic recombination. eFVIbnSMesenTiceLIgvij.

noncyclic photophosphorylation + NADP : The light driven flow of electrons pUtUpUsVrkmµKµanvdþ ³ karhUreGLicRtugedayBnøW BITwkeTA enA from water to NADP+ in oxygen-evolving photosynthesis; kúñgrsµIsMeyaKGuksIuEsnvivtþn_ ehIyRtUvkarTaMgRbB½n§BnøWTI1nigTI2. requires both photosystems I and emIl cyclic photophosphorylation . II. See cyclic photophosphorylation. non-deciduous (evergreen) : A term used to describe trees that do rukçCatiébtgrhUt ³ BaküeRbIedIm,Ierobrab;BIedImeQIEdlminRCuH not lose their leaves all at once. søwkGs;kñúgeBlEtmYy. non-disjunction : The failure of homologous chromosomes to minEckRkUm:UsUm ³ karminpþac;ecjBIKñaénRkUm:UsUmGUm:ULÚkenAeBl segregate during meiosis. emy:Us. nonmetals : All elements that do not conduct electricity. Gelah ³ ³ FatuTaMgGs;EdlmincMlgcrnþGKiÁsnI. non-permissive condition : See restrictive condition restrictive condition. l½kçx½NÐkMrit ³ emIl . nonpolar molecule : Symmetrical molecule with no unbalanced m:UelKulminb:UEl ³m:UelKulsIuemRTIEdlmanbnÞúkGKiÁsnIminesµIKña. electric charge. nonrenewable resource: A resource that is in limited supply FnFanEdlminGacsMeyaKCafµIeLIgvij)an ³ FnFanpÁt;pÁg;man and cannot be replenished. eg. coal, petrol. kMrit nigminGacbMeBjeLIgvij)an. nonsaponifiable lipid : Lipid that does not contain fatty acids and lIBItminrgsab‘Ukmµ ³ lIBItEdlKµanGasIutxøaj; nigehtuenHehIy therefore cannot be saponified by base. eTIbvaminGacrgsab‘UkmµCamYy)aseT. nonsense codon : See stop codon. kUdugKµanRkm ³ emIl stop codon . nonsense mutation : A mutation that alters a codon to one which muytasüúgmin)ankar ³ muytasüúgEdlpøas;bþÚrkUdugmYyeGayeTA encodes no amino acid i.e., UAG, UAG, UAA, UAA, or UGA. Leads to premature CakUdugmYyeTotEdlmincMlgRkmsMrab;GasuItGamIen KWfa termination during the translation b¤ UGA . muytasüúgenHnwgnaMeGaymankarbBa©b;muneBlkMnt;kñúg of mRNA. See stop codon. kMLúgeBlbkERbRkménARNm . emIl stop codon . nonvascular plant : A plant without specialized tissues for rukçCatiKµansrésnaM ³ rukçCatiEdlKµanCalikaÉkeTssMrab;dwknaM transport of food and water. GaharnigTwk. NOR : See nucleolar organizer NOR nucleolar organizer region region . ³ emIl . norepinephrine : A hormone produced by the adrenal medulla neGBIenRhVIn ³Grm:UnEdlplitedayEpñkkNþalénkenSamelItMrgenam that increases heart rate, blood pressure, and breathing rate. EdlmanmuxgarbegááIncgVak;ebHdUg sMBaFQam nigclnadegðIm. normal distribution curve : Also Gaussian known as a Gaussian or ExSekagr)ayFmµta ³ ¬eKk¾ehAvapgEdrfaExSekag b¤ bell-shaped curve, is a graph of the distribution of some continuously ExSekagragCYg ¦ CaRkabénr)aylkçN³bMErbMrYlnirnþxøHkñúgb:UBuyLasüúg variable characteristic in a ]TahrN_³ kMBs;rbs;mnusS. population e.g. height in humans.

normality : For an acid, the concentration of a solution in Nrm:alIet ³ sMrab;GasIutKWkMhab;GIuy:ugGIuRdÚEsnEdlGacmanRbtikmµ moles per liter of reactable hydrogen ion. For example, a 1.0 ehIyKitCam:UlkñúgmYylIRténsUluysüúg. ]TahrN_³ sUluysüúg M solution of HCl is 1.0 N, but a GasIutkørIRDic 1.0 M KW 1.0 N b:uEnþsUluysüúgénGasIuts‘ulpYric 1.0 M KW 1.0 M solution of H 2S0 4 is 2.0 N. 2.0 N . Northern blotting : A procedure Northern ARN by which molecules of RNA are karpþit ³ dMeNIrkarmYyEdlm:UelKul RtUv)anbMEbk separated by gel electrophoresis, gel elecrtophoresis transferred to a filter, and probed ecjBIKñaeday ehIybBa¢ÚneTAtMrgmYy nigbnÞab; mk with DNA that is complementary RtUv)anpÁÚCamYy ADN EdlbMeBjeTAnwgtMNlMdab; ARN EdleKcg; to the RNA sequence of interest; the location of the target sequence )an. TItaMgrbs;tMNlMdab;eKaledA RtUv)aneKrkeXIjedaysarEtva is found because it becomes radioactive when the probe køayCaviTüúskmµenAeBlEdl probe P¢ab;va. emIl Southern Blotting . attaches to it. See Southern Blotting, western blotting. notochord : In lower chordates and in embryos of higher BYrRbsaT ³ bMBg;RTRTg;bt;Ebn)an sßitenAtambeNþayxagxñgén vertebrates, a flexible supportive tube running the length of the kredfñak;Tab nigGMRb‘Íy:ugstVq¥wgkgfñak;x

nuclease : An enzyme that breaks bonds in nucleic acid molecules. nuyekøGas ³ Gg;suImEdlpþac;sm<½n§kñúgm:UelKulGasuItnuyekøGuic. See DNase. emIl DNase . nucleic acid : Any of several organic acids made of phosphoric GasIutnuyekøGiuc ³ GasIutsrIragÁEdlbgáeLIgedayGasIutpUsVric sár acid, sugar, and nitrogen bases. The main types are deoxyribose nig)asGasUt. manGasiutnuyekøGiucBIrRbePTsMxan;KWGasuItedGuksuIrIbU- nucleic acid (DNA), found only in nuyekøGuic ¬ ADN ¦EdlmanEtkñúgéNVyU:rbs;ekasika ¬RkUm:UsUm ¦ nig cell nuclei (chromosomes), and ribose nucleic acid (RNA), found GasuItrIbUnuyekøGuic ¬ ARN) EdlmanTaMgkñúgéNVyU: ¬RkUmU:sUmnig both in cell nuclei (chromosomes and nucleoli) and in cytoplasm nuyekøGUl ¦nigkñúgsuItU)aøs ¬mIRkUsUm ¦. (microsomes). nucleoid : The DNA-containing ADN region within the cytoplasm in nuyekøGUGuIt ³ tMbn;pÞúk kñúgsuItU)øasénekasikaRbUkarIy:Ut. prokaryotic cells. nucleolar organizer region ARNr (NOR) : A chromosomal region mCÄmNÐlnuyekøGUl ³ tMbn;énRkUm:UsUmEdlpÞúkEsnsMrab; containing the genes for rRNA; most often found in physical nigEdleRcInEtRbT³eXIjsßitenACamYynuyekøGUl. association with the nucleolus. nucleolus : An organelle within ARNr the nucleus composed of multiple nuyekøGUl ³ FatuekasikasßitkñúgéNVy:UEdlpSMeLIgBI CaeRcIn. copies of ribosomal RNA. nucleoplasm : The liquid matrix of the nucleus composed of a nuyekøGU)øas ³ sarFaturavenAkñúgéNVy:UEdlbgáeLIgedayTwk nig mixture of water and the molecules used in the construction m:UelKuleRbIsMrab;begáItTMrg;epSgeTotrbs;éNVy:U. of the rest of the nuclear structures. nucleoprotein : A molecule com- posed of nucleic acid and protein; nuyekøGURbUetGIun ³ mU:elKulEdlbgáeLIgedayGasuItnuyekøGuicnig occurs in two types, depending on whether the nucleic acid portion is RbUetGuIn. vamanBIrRbePTedayGaRs½yeTAelIfaetIEpñkGasuItnuyekøGuic DNA or RNA. Also called enaHCa ADN rW ARN . eKehAvapgEdrfasrésRkUm:aTIn. chromatin fibers. nucleoside : A purine or pyrimidine base covalently linked nuyekøGUsuIt ³ )asBuyrInb¤BIrImIDInEdlPa¢b;edaysmç½n§kUv:aLg;eTAnwg to a ribose or deoxyribose sugar molecule. m:UelKulsárrIbUsb¤sáredGuksuIrIbUs. nucleosomes : Histone clusters ADN 319 with their encircling DNA. See p. nuyekøGUsUm ³ cegáamGIusþÚnEdlrMuB½n§CMuvijeday . emIlTMBr½ . 319. nucleotide : A molecule consisting of phosphate, 5-carbon nuyekøGUTIt ³ mU:elKulEdlpSMeLIgBI pUsVat sárkabUn5 ¬rIbUs sugar (ribose or deoxyribose), and a purine or a pyrimidine base; the rWedGuksuIrIbUs ¦ nig)asBuyrInrW)asBIrImIDIn. BuyrInmanGaednIn purines are adenine and guanine, nigkanIn nigBIrImIDInmansuItUsuIn TImIn nigGu‘yra:suIl. and the pyrimidines are cytosine, thymine, and uracil. nucleotide pair : The pair of (A T G C ) nucleotides (A and T, or G and C) KUnuyekøGUTIt ³ KUénnuyekøGUTIt nig b¤ nig kñúgRcvak; in opposite strands of the DNA ADN molecule that are hydrogen-bonded pÞúyKñaénm:UelKul EdlP¢ab;KñaeTAvijeTAmkedaysarsmç½n§ to each other. GuIRdUEsn.

nucleus : 1. Eucaryotic, 1 membrane- bound organelle that éNVy:U ³ - Fatuekasikarbs;GWkarIy:UtEdlB½T§CMuvijedayPñas EdlpÞúk contains most of the DNA of the cell and directs cell division, GasIutedGuksIurIbUnuyekøGiucPaKeRcInénekasika ehIydwknaMkareFVIcMENk growth, and maintenance of the ekasika karlUtlas; nigkarEfrkSaekasika. cell. 2. The central part of an atom containing the protons and 2- EpñkkNþalrbs;GatUm EdlmanRbUtugnigNWRtug. neutrons. nullisomic : Describes an individual with a chromosomal nulIsUmic ³ BiBN’naBIÉktþ³EdlmanmuytasüúgRkUm:UsUm kuñúgenaH mutation in which both members of a chromosome pair are missing. KUTaMgBIrénKURkUm:UsUmkMBugEt)an)at;. nurse cells : See sertoli cells. ekasikaciBa©wm ³ emIl sertoli cells . nutrient upwelling : A process where colder, nutrient-rich water is karGENþtGahareLIgelIépÞTwk ³ dMeNIrEdlTwkRtCak;Cag carried up from the bottom of a body of water. nigsMbUrsarFatuciBa©wmenA)atTwkRtUv)anCBa¢ÚnmkelIépÞTwk. nutrients : Substances required by the body for growth, reproduction, sarFatuciBaw©m ³ sarFatuEdlsarBagÁkayRtÚvkar edIm,IlUtlas; or repair that are provided by food. bnþBUC b¤RTRTg;sarBagÁkay ehIyRtÚv)anpþl;edaycMNIGahar. nutrition : Branch of science that deals with the composition, cMNIGahar ³ saxaénviTüasaRsþEdlsikSaBIsmasPaBpSM karerobcM preparation, consumption, and processing of food. The process by kareRbIR)as; niglMnaMénkarplitGahar. dMenIrEdlPavrs;TTYl which an organism obtains and nigeRbIR)as;Gahar. uses food. nyctinasty : The “sleep movements” of leaves in response søwkedk rWsøwkxøb ³ clnaedkrbs;søwkrukçCati EdlCakareqøIytb to changes in turgor of cells at the base of their petioles. eTAnwgkarERbRbYlsMBaFe)a:grbs;ekasikaenAKl;Tgsøwk. ]TahrN_³ søwkRBHxøbenAeBlEdleyIgb:Hva. nymph : An immature stage in metamorphosis that resembles an dwkedO ³ dMNak;kalminTan;eBjv½yénbMErrUb EdlmanlkçN³Rsedog adult. stVeBjv½yEdr. O obesity : A condition characterized by excessive body fat. PaBFat;eBk ³ sßanPaBEdlsMKal;edayxøaj;;kñúgsarBagÁkayeRcIn hYsehtu. objective : The lens in a compound microscope that magnifies the EkvBRgIkeRkam rWGubsicTIb ³ EkvBRgIksßitenAkñúgmIRkUTsSn_smas object being observed. EdlBRgIkvtßúEdlRtUvemIl. obligate : An organism that can only live in one environment. e.g. caM)ac; ³ Pavrs;EdlGacrs;enAEtkñúgbrisßanmYyb:ueNaÑH. ]³ mnusS Humans can only live in an atmosphere containing oxygen. Gacrs;)anEtkñúgbrisßanEdlmanGuksIuEsnb:ueNÑaH. obligate anaerobe : Anaerobic bacteria that are poisoned by )ak;etrIKµanxül;caM)ac; ³ )ak;etrIKµanxül; EdlRtUv)anbMBuleday oxygen. GuksIuEsn. obligate intracellular parasites : Infectious particles (viruses) that brasitkñúgekasikacaM)ac; ³ vIrusEdlGacmanskmµPaBEtenAkñúg can function only when inside a living cell. ekasikamanCIvit.

observation : The process of using the senses to record events. karsegát ³ dMeNIrénkareRbIviBaØaNedIm,Ikt;RtaehtukarN_. Occam’s razor : A principle of Occam logic that suggests that the best RTwsþI ³ eKalkarN_d¾‘smehtuplmYy EdlesñIeLIgfa explanation of an event is the simplest, using the fewest karBnül;RBwtiþkarN_d¾l¥bMput KWkarbnül;gaybMputnigeRbIkarsnñidæanén assumptions of hypotheses. smµtikmµticbMput. occipital : Relating to the posterior part of the skull. By ³ EdlTak;TgeTAnwgEpñkxageRkayénllad¾k,al. ocellus : A simple, pigment-containing photoreceptor sñamEPñk ³ FµÜlBnøWeTalmanCatiBN’énstV\tq¥wgkgCaeRcInepSg² found in a variety of unrelated invertebrates. Kña. ochre codon : A codon that does not code for the insertion of an kUdugsþúbRkhm ³ kUdugEdlmincMlgRkmsMrabkar;bEnßmGasuItGamIen amino acid into a polypeptide chain, but signals chain cUleTAkñúgRcvak;b:UlIbuibTIt b:uEnþeGaysBaØadl;karbBa©b;Rcvak;. termination. The ochre codon is kUdugRkhm KW UAA . emIl stop codon . UAA. See stop codon. octet rule : Chemical stability is implied if an atom has a set of viFanGdæta ³ sißrPaBKImIRtÚv)anbBa¢ak;ebIsinCaGatUmmYyman eight outer electrons (sp electrons). sp Note that hydrogen does not obey eGLicRtúgR)aMbIenARsTab;eRkAbg¥s; ¬ eGLicRtúg¦. kt;sMKal; this rule. faGIuRdÚEsnmineKarBtamviFanenHeT. ocular : The lens in a compound microscope that magnifies the GUKuyEl ³ EkvBRgIkkñúgmIRkUTsSn_smas EdlBRgIkrUbPaB Edl image produced by the objective lens. begáItedayEkvBRgIkGubsicTIb. oestrus (estrus) or ‘heat’: A period lasting from 5 to 60 days, kMedA ³ ry³eBlBI5 dl;60éf¶EdlstVjIeBjv½yPaKeRcInmancMNg; when most adult female animals desire and allow copulation. It is nigGnuBaØatieGaymankarBak;Kña. vaekItmanenAeBlmandMeNIrGUvul when ovulation has occurred and nigeRcInEtmankarbgákMeNIt. so fertilisation is most likely. offspring : Descendants of a set of parents. kUn ³ kUnrbs;em)a. oils : Triacylglycerols that are liquids at room temperature. eRbg ³ RTIGasIulKøIesr:ulEdlravenAsItuNðPaBkñúgbnÞb;. Okazaki fragment : The small, Okazaki ADN discontinuous strands of DNA Ggát; ³ Rcvak; dac;²tUc²EdlRtUv)anbegáItkñúg produced during DNA synthesis. ADN 319 See p. 319. eBlsMeyaK . emIlTMBr½ . olfactory epithelium : The cells of the nasal cavity that respond to eGBIetlüÚmXanviBaØaN ³ ekasikaRbehagRcmuHEdleqøIytbeTAnwg chemicals. FatuKImI. olfactory lobe : A part of the brain in vertebrates concerned with kMBkXanviBaØaN ³ EpñkmYyrbs;xYrk,alstVq¥wgkgEdlTak;Tg smell. eTAnwgkøin. oligonucleotides : A short sequence of nucleotides. GUlIkUnuyekøGUTIt ³ tMNlMdab;xøIénnuyekøGUTIt. oligosaccharides : Carbohydrates that contain two to ten mono- GUlIkUsakarIt ³ kabUGIuRdatEdlmanm:UNUsakarItBIBIreTAdb; dUcCa saccharides, such as table sugar and milk sugar (disaccharides). sársakarU:s nigsárTwkedaH ¬DIsakarIt¦.

ommatidium (pl. ommatdia) : Individual parts of the compound ÉktaEPñksmas ³ EpñknImYy²énEPñksmasrbs;stVl¥it nig eye of insects and other arthropods. Each ommatidium contains a group GakRtUb:UtepSgeTot. ÉktaEPñknImYy²manekasikaerTInmYyRkum of retinal cells surrounded by EdlB½T§CMuvijedayekasikaCatiBN’ nigmanEkvEPñkrbs;va. pigment cells and has its own lens. omnivore : A consumer that eats both plants and animals. sBVasI ³ GñkeRbIR)as;EdlsIuTaMgrukçCati sIuTaMgstV. oncogene : A gene whose activity promotes uncontrolled cell growth EsnbgáCMgWmharIk ³ EsnEdlmanskmµPaBCMrujdl;karlUtlas; i.e. cancer in eukaryotic cells. minkMnt;;. ]TahrN_ ³ CMgWmharIkénekasikaGWkarIy:Ut. ontogenetic : Relating to the development of an individual GugtUesenTic ³ EdlTak;TgeTAnwgkarlUtlas;énÉktþ³mYy. organism. ontogeny : The development of an individual from egg to old age GugtUesnI ³ karlUtlas;énÉktþ³mYyBIsu‘trhUtdl;cas;. (senescence). oogamy : Sexual reproduction in which the male gamete is GUGUkamI ³ karbnþBUCedayePT EdlkaEm:teQaµlmanpøaEsl flagellated and the female gamete is a larger, non-motile egg cell. nigkaEm:t jIFMCagnigGcl½t. oogenesis : The specific name II given to the gametogenesis process kMNGUvUsIut ³ KWCaeQaµHEdleKdak;eTAelIdMeNIrkarkMNkaEm:t that leads to the formation of eggs. EdlnaMeTAdl;karbegáItGUvUsIut II . oogonium : An egg-producing structure found in some plants. GUGUkUnI ³ TMrg;plitkaEm:tjIkñúgrukçCatimYycMnYn. opal codon : The codon UGA UGA which does not code for any amino kUdugsþúbexov ³ kUdug EdlmincMlgRkmsMrab;GasuItGamIeneT acid but causes chain termination. stop codon See stop codon. b:uénþeFVIeGaymankarbBa©b;énRcvak;. sUmemIl . open circulatory system : A circulatory system in which blood RbB½n§rbt;QamebIk ³ RbB½n§rbt;Qam EdlQamminsßitEtenAkñúg is not entirely contained in vessels. srésQameT. operant conditioning : A form of learning in which a certain karbegáItl½kçx½NÐBiesaFn _³ TMrg;énkareronEdltMNbrMejacxøHRbRBwtþ response to a stimulus is reinforced. eTAedaykarpþl;rgVan;. operator region : A region of a ADN DNA molecule that interacts with a tMbn;Rbtibtþikar ³ tMbn;mYyrbs;m:UelKul EdlmanGnþrGMeBI specific repressor protein to control the expression of an adjacent gene CamYyRbUetGuInbg¥ak;yfaRbePTedIm,IRtYtBinitükarsMEdgecjénEsn or gene set. Cab;Kñab¤RkumEsnmYy. operculum : 1. The gill cover in bony fish. 2. The lid of the KMrbRskI ³ 1- KMrbRskIRtIq¥wg. 2- KMrbs,:r:g;rbs;Esø. sporangium in mosses. operon : Set of genes in bacteria that work together. Genes within GUeb:r:ug ³ RkumEsn)ak;etrIEdleFVIkarrYmKña. EsnGUeb:r:ugGacRtÚv)an the operon are either turned on or off collectively. pþac;ecjb¤P¢ab;KñaTaMgGs;. operon model : A concept of gene regulation in which production of KMrUGUeb:r:ug ³ bBaØatBItMrUvEsn EdlkarbegáItGg;suImRtUv)anCMruyeday an enzyme is induced by the presence of the substrate and then vtþmans‘ubRsþa nigbnÞab;mkRtUv)anbg¥ak;eTAvijeday Gvtþmans‘ubRsþa. repressed by the absence of the sUmemIl induction , repression . substrate. See induction, repression.

opposable (adj) : Working opposite each other. eg. Thumb EdlpÞúyKña rWEdlRbqaMgKña ³ dMeNIrkarpÞúyKñaeTAvijeTAmk. and index fingers. ]TahrN_ ³ emédnigcg¥úléd. opposite phyllotaxis : Leaves occurring in pairs at a node. søwkQm ³ søwkEdltMerobCaKU²KñaenAtamfñaMgnimYy². optic lobes : The parts of the brain that process visual information. kMBkGubTic ³ EpñkénxYrk,alEdlTTYlnigviPaKBt’manKMehIj. oral groove : An opening in a paramecium through which food is cg¥Úrmat; ³ rn§Rbehagén)a:ra:emsIu EdlGaharRtUv)anelbcUl. ingested. orbit : The hole in the vertebrate skull that contains the eye. RbLg;EPñk ³ RbehagenAkñúgllad¾k,alstVq¥wgkgEdlpÞúkEPñk. orbital : The area surrounding the nucleus of an atom, able to hold a Grb‘Ítal; ³ tMbn;EdlenAB½T§CuMvijéNVy:Urbs;GatUm ehIyGacpÞúk maximum of two electrons. eGLicRtugy:ageRcInbMputBIr. orbital notation : Shorthand for indicating the orbital “addresses” KMnUstagGrb‘Ítal; ³ nimitþsBaØasMrab;bgðajTItaMgGrb‘Ítal;én (location) of electrons. An atom ls with two ls electrons, two 2s eGLicRtúg. GatUmmYyEdlmaneGLicRtúgBIrelIRsTab;eGLicRtúg nig electrons, and a 2p electron could egLicRtugBIrelI 2s nigmaneGLicRtúgmYyelIRsTab; 2p Edlb:UBuyLa- have its orbital population 2 2 1 expressed as 1s 2 2s 2 2p 1. süúgGrb‘Ítal;vaGacRtÚv)anbgðajCa 1s 2s 2p . order : A group of related taxonomic families. lMdab; ³ RkumGMbUrEdlmanTMnak;TMngKñaenAkñúgkareFVIcMENkfñak;. organ : A structure composed of several tissues working together to srIragÁ ³ TMrg;EdlbgáeLIgedayCalikaeRcIn ehIydMeNIrkarmuxgar perform a function. eg. heart, stomach, kidney etc. mYyrYmKña. ]TahrN_³ ebHdUg RkBH tMrgenam. organ system : A group of organs working together to perform a RbB½n§srIragÁ ³RkumsrIragÁEdlrYmKñadMeNIrkarmuxgarmYy. ]TahrN_³ function. eg. Blood circulatory system. RbB½n§rbt;Qam. organelle : A structure within a cell that has a specific function. eg. Fatuekasika ³ TMrg;enAkñúgekasikaEdlmanmuxgaryfaRbePT. mitochondria. ]TahrN_³ mItUkugRDI. organic acid : A hydrocarbon derivative containing a functional GasIutsrIragÁ ³ RsLayGIuRdUkabYEdlmanbgÁMnaTImYy nigmanrUbmnþ group having the formula –COOH - COOH . organic chemistry : The study of carbon chain and carbon ring KImIsrIragÁ ³ karsikSaGMBIsmasFatukabUnExSRtg;nigsmasFatukabUn compounds. ExSbiT. organic compound : A chemical compound containing one or more smasFatusrIragÁ ³ smasFatuKImI EdlmanGatUmmYyb¤eRcInsßitenA carbon atoms in chain or ring form. kñúgTMrg;ExSRtg; b¤ ExSbiT. organic molecules : Complex molecules whose basic units are m:UelKulsrIragÁ ³ kMupiøcm:UelKul EdlFatubgásMxan;rbs;vaKWGatUmkabUn carbon atoms in chains or rings. EdltMerobCaExSRtg; rWCaExSbiT. organism : An individual plant or animal, either unicellular or Pavrs; rWsarBagÁkay ³ Éktþ³rukçCati rWstVEdlGacCaÉkekasika multicellular. rWCaBhuekasika.

organismal theory A theory describing how whole organisms, RTwsþIPavrs; ³ RTwsþIEdlBiBN’naBIPavrs;TaMgmUl ¬minEmnekasikaeT¦ not cells, are the fundamental organizational units of living faCaÉktarUbpÁúMmUldæanrbs;Pavrs;. tamRTwsþIenH Pavrs;lUtlas;eday organisms; according to this karEcksarBagÁkayTaMgmUleTACaekasikaCaeRcIn minEmnedaykar theory, organisms develop by compartmenting the whole begáItPavrs;enaHBIekasikaeT. organism into cells, not by building the organism from cells. organohalogen : Organic compound in which a halogen GaLÚEsnsrIragÁ ³ smasFatusrIragÁEdlGaLÚEsndUcCa PøúyGr kør (fluorine, chlorine, bromine, or iodine) has replaced one or more RbÚm b¤ GIuy:Ut )anCMnYsGIuRdÚEsnmYyb¤eRcInénGIuRdÚkabY. hydrocarbon hydrogens. orgasm : An intense feeling of pleasure during sexual excitement. TIbMputénteRmk ³ es‘rItMNbeTAnwgrMejacpøÜvePTsaMjauM EdlbNþal eGaymanGarmµrN_pøÚvePTy:agxøaMg. orifice : Any opening or aperture like a mouth. rn§mat; ³ Rbehag rWrn§dUcmat;. origin : The point of attachment of a muscle to a nonmoving bone. RbPB ³ cMnuc b¤kEnøgP¢ab;;sac;duMeTAnwgq¥wgGcl½t. ornithine cycle : See urea cycle. vdþG½rnIsIun ³ sUmemIlvdþ Urea cycle . orogeny : Process of crustal uplift or mountain building. kMNPñM ³ dMeNIrrujTUlsMbkEpndIeLIg rWkarkekItPñM. orphon : Single copy of a gene that is usually found in a group of Grpug ³ EsneTalEdlCaFmµtamankñúgRkuménEsndUcKñaCaeRcIn. many identical copies. For example, histone genes are usually ]TahrN_ ³ EsnGuIsþÚnCaFmµtaelceLIgCaRkumdUcCaRKYsarmYyEdl present as a group like a family, of manrab;ryEsndUc²Kña. EsnGuIsþÚnmYyEdlRbT³eXIjenAkEnøgepSg several hundred identical copies. A single copy of a histone gene found eTotkúñgesNUmRtUv)aneKniyayfa mankarvegVgecjBIRKYsarrbs;va elsewhere in the genome is said to have lost its family and is regarded nigRtUv)ancat;TukCaGrpug. as an orphon. ortho- (o-) : Prefix used to designate substituent position on a GrtU- ³ buBVbTEdleRbIsMrab;bBa¢ak;TItaMgRkúmCMnYsenAelI siucbg;Esn. benzene ring. The ortho position is immediately adjacent to the parent TItaMgGrtUenACab;nwgRkúmCMnYsem. substituent. osmosis : Process in which two solutions separated by a semi- GUsµÚs ³ lMnaMEdlsUluysüúgBIrRtUv)anEjkecjBIKñaedayPñas permeable membrane attempt to equalize their concentrations by GDÄRCabeFIVeGaykMhab;rbs;vaesµIKñaedaykarqøgkat;énm:UelKultUc²tam passing small molecules through Pñas. RbB½n§CIvsaRsþeRbIGUsµÚsedIm,IeGayTwknigsarFatuciBa©wmqøgkat; the membrane. Biological systems use osmosis to pass water and Pñasekasika. ]TahrN_³ clnam:UelKulTwkqøgkat;PñasBIkEnøgEdl some nutrients between cells. e.g. The movement of water molecules mankMhab;x

osmotic pressure (osmotic potential or solute potential) : sMBaFGUsµúÚs ³ rgVas;sMBaFEdlbNþalmkBIkarbBa¢Únm:UelKulFatu Measure of the pressure driving the transfer of solvent molecules rMlayqøgkat;PñasBIsUluysüúgEdlmankMhab;FaturlayTabeTA across a membrane from a solution sUluysüúgEdlmankMhab;Faturlayx

oval window : The membrane – covered opening of the cochlea, to bg¥ÜcragBgRkeB I ³ PñasRKbRbehagbMBg;ragKUTxügEdlP¢ab;eTAnwg which the stapes is attached in the inner ear. qå¥gQñan;kñúgRtecokkñúg. ovary : 1. The reproductive organ oogenesis, germinal that produces female gametes. See GUEv ³ 1- srIragÁbnþBUCEdlbegáItkaEm:tjI. emIl oogenesis, germinal epithelium, epithelium, corpus luteum corpus luteum. 2. The enlarged, . 2- EpñkrIkFMEdlpÞúkGUvul éneksrjI ovule- bearing portion of a carpel b¤kBaú©MeksrjIEdlrlaycUlKña. bnÞab;BIkarbgákMenItmk or of a cluster of fused carpels; after fertilization, an ovary matures GUEvvivtþeTACaEpø. into a fruit. overlapping code : A genetic code in which a nucleotide is shared by KMnrEsn ³ RkmesenTicEdlnuyekøGUTItmYyRtUv)andak;rYmKñaeday two codons next to each other. kUdug2enACitKña. oviduct : A tube that carries eggs from the ovary. éds,Ún ³ bMBg;EdlnaMkaEm:tBIGUEv. oviparous, oviparity : Reproduction in which eggs are GUvI)a: ³ karbnþBUCEdlsu‘t®tUv)anBgecjmkeRkAedayemrbs;va. released by the female; development of offspring occurs karlUtlas;énkUnRbRBwtþeTAeRkAxøÜnem. outside the maternal body. ovipositor : A structure in female insects through which fertilized bMBg;beBa©js‘ut ³ TMrg;enAkñúgstVl¥itjIEdls‘utbgákMeNItRtUv)an eggs travel to the outside of the body. beBa©jmkeRkAsarBagÁkaytamTMrg;enH. ovoviviparous : The embryo develops inside the mother but is GUvUvIvI)a: ³ GMRb‘Íy:uglUtlas;enAkñúgsu‘tkñúgeBaHem. KµansukeT. separated by egg membranes. There is no placenta. eg in some ]TahrN_ cMeBaHRtI lµÚn nigstVl¥itmYycMnYn. fishes, reptiles and insects. ovulation : The release of an egg from the ovary. dMeNIrGUvul ³ karbeBa©jkaEm:tjIBIGUEv. ovule : A structure in the ovary of a flower that becomes a seed after GUvul ³ TMrg;kñúgGUEvpáa EdlnwgkøayeTACaRKab;bnÞab;BIkarbgákMenIt. fertilization. ovum: The female gamete or egg. kaEm:tjI oxaloacetate (oxaloacetic acid) : A four-carbon organic acid that is GuksaLÚGaestat ¬GasIutGuksaLÚGaesTic¦ ³ GasuItsrIragÁman converted to citric acid by the addition of an acetyl group in the kabUn4 EdlRtUv)ankøayCaGasuItsuIRTicedaykarbEnßmRkumGaesTIl first step of the Krebs cycle; enAkñúgvKÁTI1énvdþERkb. GasuItGuksaLÚGaesTic k¾Ca oxaloacetic acid is also the product of the carbon dioxide fixation of plitplénkarP¢ab;]sµ½nkabUnicrbs;GasuItpUsVreGNulBIruyvic phosphoenolpyruvic acid in C4 and CAM photosynthesis. enAkñúgrsµIsMeyaK C4 nig CAM Edr .

oxidation : The loss of electrons from an atom or molecule that is GuksIutkmµ ³ kar)at;bg;eGLicRtugBIGatUm b¤m:UelKulmYy EdlTak;Tg involved in an oxidation reduction (redox) reaction; oxidation eTAnwgRbtikmµGuksIudUerdukmµ. GuksuItkmµbBa©ÚnfamBlBIsarFatumYy removes energy from one EdlCaKUrCamYynwgkarbEnßmfamBlkñúgeBlCamYyKñaeTAnwgsarFatumYy substance, which is coupled with the simultaneous addition of epSgeTotedaykarbnßy. ]TahrN_³ enAeBlEdkeRcHvabþÚrPaB energy to another substance by reduction. e.g. When iron rusts it GuksIutkmµrbs;vaBI 0eTA + 3 edaykarpþl;eGLicRtúgbIkñúgdMNak;karBIr changes its oxidation state from 0 Beta-Oxidation to + 3 by giving up three electrons énlMnaMenH. dUecñHvargGuksIutkmµ. emIl . in a two-step process, thus it is oxidized. Also see Beta- Oxidation. oxidation number : Charge predicted for an atom by the elec- cMnYnGuksIutkmµ ³ bnÞúkEdlRtÚv)ansnµt;TuksMrab;GatUmmYy tamRTwsþI tron-transfer bonding theory, even if the molecule is covalent; or the énkarP¢ab;benÞreGLicRtúg eTaHCam:UelKulCakUv:aLg; b¤cMnYneGLicRtúg number of electrons shared by the RtÚv)andak;rYmedayGatUmkñúgm:UelKulkUv:aLg;b¤kUv:aLg;b:UEl. atom in a covalent or polar covalent molecule. oxidation-reduction reactions : (redox) Electron-transport RbtikmµGuksIudU-erdukmµ ³ RbtikmµdwknaMeGLicRtug kñúgenaHm:UelKul reactions in which the molecules losing electrons become oxidized Edl)at;bg;eGLicRtugkøayCaGuksIutkr cMENkÉmU:elKulEdlcMeNj and those gaining electrons become eGLicRtugkøayCaerdukr. reduced.. oxidative phosphorylation : ATP ADP Process that synthesizes ATP from pUs½VrkmµtamGuksIutkmµ ³ dMeNIrsMeyaK BI nigpUsVat ADP and inorganic phosphate using energy stored in a proton GsrIragÁedaykareRbIfamBlEdlsþúkkñugRbÚtug. gradient. oxidizing atmosphere : An atmosphere that contains molecular briyakasGuksIuEsn ³ briyakasEdlmanm:UelKulGuksIuEsn. oxygen. oxytocin : A hormone produced by the hypothalamus that causes GuksIutUsIun ³ Grm:UnplitedayGIub:UtaLamusEdleFIVeGays,ÚnkRnþak; uterine contraction during labor and promotes milk flow from the enAeBlsMralkUn nigeFIVeGayRkeBjTwkedaHbeBa©jTwkedaH. mammary glands. ozone : A form of oxygen (0 ) in 3 (0 ) the stratosphere that shields living GUsUn ³ TMrg;mYyrbs;GuksIuEsn 3 enAkñúgRsTab;briyakasEdl organisms from intense ultraviolet radiation. karBarPavrs;BIrsµIsVayG‘ulRtad¾xaøMg. P p0H : Measure of hydroxide ion p0H -log[OH -] concentration; equals - log[OH -]. ³ rgVas;kMhab;GIuy:ugGIuRdúksIutEdlmantMélesIµnwg . P1 generation : The first parental generation in a genetic cross. CMnan;em)a ³ CMnan;em)aTI1kñúgkarbgáat;esenTic. pacemaker : A group of specialized cardiac muscle cells GñkkMNt;clnaebHdUg ³ Rkumekasikasac;duMebHdUg EdlmanÉkeTs that generate electrical impulses, thus causing heart muscle to begáItcrnþrMejaceFIVeGayebHdUgkRnþak;. contract.

pachytene : The stage in prophase I 1 of meiosis when the synapsed )a:KIEtn ³ vKÁkñúgRbUpas énemy:UsenAeBlEdlRkUm:UsUmGUm:ULÚk homologous chromosomes split longitudinally (except at the ruMKgelIKña)aneRbHtambeNþay ¬elIkElgEtRtg;sg;RtUEm ¦ehIy)an centromere), producing a group of begáItRkummYyEdlmanRkUma:TIt4 ehAfaetRtat. four chromatids called a tetrad. paedogenesis : Reproduction by young or larval forms. especially eb:dUsWENs ³ karbnþBUCedayxøÜnenAekµg rWenACakUnjas; CaBiess parthenogenesis. )a:etNUsWENs. paedomorphosis : Condition in which a larva becomes sexually eb:dUmpUs ³ l½kçx½NÐEdlkUnjas;køayCastVmanlkçN³ePTeBjv½y mature without attaining the adult body form. Paedomorphosis may edayTMrg;rUbragminTan;eBjv½yenAeLIy. eb:dUm:rpUsGacsMerc)aneday be achieved by neoteny or by enGUetnI rWedayRbU:sWENs. progenesis. palatoquadrate : Upper jaw element of primitive fishes and )a:LatUkaRdat ³ q¥wgfÁamelIrbs;RtICMnan;edIm nigRtIq¥wgx©I CaEpñkmYy chondrichthyes, portions of which contribute to the palate, jaw EdlRtUvnwgq¥wgRkGUm snøak;fÁam nigq¥wgRtecokkNþalénstVq¥wgkgepSg articulation, and middle ear of eTot. other vertebrates. palea : In grasses, the upper part of the two covers of the flowers. sMbkeBaHRKab; ³ cMeBaHrukçCatiRkamIen CasMbkxagelIénsMbkTaMgBIr rbs;páa. paleospecies : A species defined only by fossil morphology. RbePTbUraN ³ RbePTmYyEdlrtUv)anBnül;EtedayrUbsa®sþpUsIul. Paleozoic : The geological era between the Precambrian and the )a:elGUsUGiuc ³ s½kPUKBÖsa®sþcenøaHbuerkMRb‘Íeyog nigemsUsUGuic Mesozoic, approximately from 550 320 to 200 million years ago. See p. manGayuRbEhlBI550 eTA200lanqñaM. emIlTMBr½ . 320. palindrome : In nucleic acids, a sequence in which the base pairs EplInRdUm ³ kñúgGasuItnuyekøGuic vaCatMNlMdab;EdlKU)asGandUcKña / / / read the same on complementary GAATTC 3 ’ , strands (5’--->3’). For example: enAelIRcvak;bMeBj ¬ % # ¦. ]TahrN_ ³ % 5’GAATTC3’, 3’CTTAAG5’. 3 ’ CTTAAG 5 ’ . TaMgenHekItmaneLIgCajwkjab; CakEnøgsMrab;kar These often occur as sites for restriction endonuclease TTYlsaÁl;nigkarkat;rbs;Gg;suImersRsÞIcsin Gg;dUnuyekøGas. recognition and cutting. palingenesis : The stages in the development or ontogeny of an )a:LaMgswENs ³ dMNak;énkarlUtlas;rWGugtUesnIénstVEdl animal that are inherited from ancestral species, such as gill slits )anTTYlmrtkBIbuBV dUcCasñamrgVHRskIenAelIKP’énfnikstV. in the unborn of mammals. palisade mesophyll : A layer of long narrow cells under the upper )a:lIsatemsUPIl ³ ekasikatUc²Evg²mYyRsTab;sßitenAeRkam epidermis of a leaf . See p. 330. eGBIEDmxagelIénsøwk. emIlTMBr½ 330 . palmate venation : A type of venation in which several veins RTnugkgðar ³ RbePTtMMerobRTnugsøwkEdlRTnugCaeRcInEbkecjBIcMnuc radiate from a single point. 329 See p. 329. mYy. emIlTMBr½ . palmately compound : A type of leaf in which the leaflets join søwkkgðarrYm ³ RbePTsøwkEdlkUnsøwkP¢ab;KñaTaMgGs;munP¢ab;eTATgsøwk. together before attaching to the 329 petiole. See p. 329. emIlTMBr½ .

pancreas : An organ that secretes enzymes for intestinal digestion as lMEBg ³ srIragÁEdlbeBa©jGg;sIumsMrab;karrMlayGaharkñúgeBaHevon- well as the hormones insulin and 322 glucagon. See p. 322. tUc RBmTaMgbeBa©jGrm:UnGaMgs‘uylIn nigKøúykakug. emIlTMBr½ . pancreatic duct : A tube that transports digestive enzymes from bMBg;lMEBg ³ bMBg;EdldwknaMGg;sIumrMlayGaharBIlMEBgeTAkan;Kl; the pancreas to the duodenum. See 322 p. 322. eBaHevon. emIlTMBr½ . pancreatic juice : A substance produced by the pancreas that rslMEBg ³ sarFatuplitedaylMEBg EdlmanGg;sIumrMlayGahar contains digestive enzymes and neutralizes stomach acid in the nigbnSabGasIutRkBHenAKl;eBaHevon. duodenum. Pangaea (Pangea) : Single supercontinent that existed during pan;eco ³ mhaTVIbmYyEdlekIteLIgenABak;kNþals½k)a:elGUsUGiuc the mid-Paleozoic and consisted of all modern continents in direct nigEdlrYmmanTVIbfµI²TaMgGs; EdlCab;KñapÞal;tamlkçN³PUmisaRsþrUb. physical contact. Compare with eRbobeFobCamYynwg Gondwanaland . Gondwanaland. panicle : a complex branched cluster of flowers. kBa©Múpáa ³ kBa©úMEmkpþúMpáa. papilla : A small nipple-like projection. G®Ba©aj ³ BktUc²ragdUccugedaH. para- (p-) : Prefix used to designate substituent position on a ):ara:- ³ buBVbTEdleRbIsMrab;kMnt;TItaMgRkúmCMnYselIsiucbg;Esn. benzene ring. The para position is across from the parent substituent. TItaMg):ar:aRtÚvqøgBIRkúmCMnYsem. paracentric inversion : Chromosome inversion that does cMras;)a:ra:sg;RTic ³ cMras;Ggát;RkUm:UsUmEdlminKitTaMgsg;RtUEmeT. not include the centromere. parapatric : Occurring in adjoining places. )a:r:a)a:RTic ³ EdlekIteLIgenAkñúgkEnøgCab;²Kña b¤Ek,r²Kña. parapatric speciation : Speciation that occurs between adjoining karbegáItRbePTfµI)a:r:a)a:RTic ³ karbegáItRbePTfµI EdlekItmanrvag populations, often caused by low dispersal range of the individuals. b:UBuyLasüúgEk,rKña ehIyPaKeRcInbgáedayRkumÉktþ³TabEdlenA r)a:t;r)a:y. paraphyletic : Term applied to a group of organisms that does not )a:r:aPIelTic ³ vaküs½BÞ EdlniyaysMedAeTAelIRkumPavrs;EdlKµan contain all the descendants of a single ancestor. kUnecATaMgGs;énbuBVeTal. paraphyses (sing. paraphysis) : Sterile filaments that grow among )a:r:aPIs ³ PILam:g;minGacbnþBUC)anEdlduHlUtlas;kñúgcMeNam the reproductive cells of certain fungi and brown algae. ekasikabnþBUCrbs;pSitnigsarayetñat. parasexual : Condition describing recombination of genes from )a:r:aePT ³ sßanPaBBN’naBIbnSMfµIénEsnecjBIÉktþ³epSg²KñaEdlmin different individuals which does not involve meiosis, gamete Cab;Tak;Tgnigemy:Us karbegáItkaEm:t b¤karbegáItsuIkUt. ]TahrN_ ³ formation, or zygote production. karbegáItekasikalUtlas;GuIRb‘Ít. The formation of somatic cell hybrids is an example. parasite : An organism that lives on or in another organism and gets brasit ³ Pavrs;Edlrs;enAelIb¤enAkñúgPavrs;mYyepSgeTot niigRsUb nourishment from it. ykGaharBIPavrs;enaH. parasitism : A relationship in which one organism lives on or in PaBCabrasit ³ TMnak;TMngEdlPavrs;mYyrs;enAelIb¤enAkñúgPavrs;mYy another organism, usually harming the host. eTot nigeRcInEtpþl;plGaRkk;dl;;FµÜlrbs;va.

parasymbiosis : Living together without either mutual benefit or )a:r:ashR)aN ³ Edlrs;enACamYyKña edayKµanplRbeyaCn_ disadvantage. eGayKñaeTAvijeTAmkeT. parasympathetic nervous system : A part of the autonomic nervous RbB½n§RbsaT)a:r:asMa)a:Tic ³ EpñkénRbB½n§RbsaTs½VyRbvtþEdleFIV system that returns the body to normal after an emergency and eGaysarBagÁkayvilmksPaBedImvijbnÞab;BImaneRKaHGasnñ nigrkSa maintains homeostasis. lMnwgkñúgsarBagÁkay. parathyroid glands : Four small endocrine glands on the RkeBj)a:r:aTIr:UGIut ³ RkeBjbeBa©jkñúgtUc²4 sßitenAelIépÞrbs;TIr:UGIut surface of the thyroid that produce parathyroid hormone. EdlplitGrm:Un)a:r:aTIr:UGIut. parathyroid hormone : A hormone secreted by the Grm:Un)a:r:aTIr:UGIut ³ Grm:UnEdlbeBa©jedayRkeBj)a:r:aTIr:UGIut EdltMrUv parathyroid glands that regulates the levels of calcium and kMritGIuy:ugkal;süÚm nigGIuy:ugpUsVatenAkñúgQam. phosphate ions in the blood. parenchyma : The plant tissue type characterized by relatively )a:r:g;suIm ³ RbePTCalikarukçCatiEdlsMKal;edayekasikamanCIvit simple, living cells having only primary walls specialized for samBaØ nigmanEtPñasTImYyEdlmanÉkeTssþúkGahar. storage of food. parent nucleus (or isotope) : Unstable atom prior to radioactive éNVy:Uemb¤GIusUtUb ³ GatUmKµansßirPaBmunnwgrgkarbMEbkviTüúskmµ. decay. parental gamete : See noncrossover gamete noncrossover gamete. kaEm:tem)a ³ emIl . parietal placentation : Refers to the attachment of ovules CMnab;GUvultamPñas ³ karP¢ab;GUvul ¬)aøsg;ta ¦ tambeNþayPñasGUEv (placentation) along the wall of an ovary (i.e., parietal). parthenocarpy : Development of fruit without fertilization. )a:etNUkaBI ³ karlUtlas;rbs;EpKµankarbgákMenIt. parthenogenesis : Development of an unfertilized egg into a )a:tWNUsWENs ³ karlUtlas;éns‘utminbgákMenIteTACastVeBjv½y functional adult. manRKb;lkçN³. partial diploids : See merozygote. DIbøÚGIutmineBjelj ³ emIl merozygote . partial dominance : See incomplete dominance incomplete dominance. lubmineBjelj ³ emIl . partial pressure : Pressure exerted by each component of a mixture of sMBaFtamEpñk ³ sMBaFEdl)anbegáItedaysmasPaKnImYy²én gases. The total of the partial pressures of all gases equals the l,ay]sµ½n. sMBaFtamEpñksrubén]sµ½nTaMgGs;esµInwgplbUksrub total pressure of the gas. rbs;sMBaFsrubén]sµ½nenaH. Pascal (Pa) : The pressure unit (i.e., energy per unit volume) used )a:sáal; ³ ÉktasMBaF ¬KWCafamBlkñúgÉktamaD ¦EdleRbIedIm,Ivas; to measure water potential; one Pascal equals the force of one b:Utg;EsülTwk. mYy)a:sáal;esµInwgkMlaMgmYyjÚtunkñúgmYyEm:Rtkaer. Newton per square meter; one sMBaFGat;m:UEsVesµInwg 1.0 x 10 5 Pa . atmosphere of pressure equals 1.0 x 10 5 Pa. passage cell : Endodermal cells of root that have a thin wall that ekasikaqøgkat; ³ ekasikaGg;dUEDmrbs;rwsEdlmanPñasesþIg permits solutes to pass through. EdlGnuBaØatieGayFaturlayqøgkat;)an.

passive immunity : A type of immunity produced by receiving PaBsaMuGkmµ ³ RbePTPaBsuaMEdlbegáItedaykarTTYlGg;TIkrBIÉktþ³ antibodies made by another individual. e.g. babies can receive mYyepSgeTot. ]TahrN_ ³ TarkGacTTYl)anPaBsaMuGkmµBITwkedaH passive immunity from their mþay. mother’s breast milk. passive transport : Movement of molecules across a membrane kardwknaMGkmµ ³ clnarbs;m:UelKulqøgkat;PñasedayKµankareRbI without the use of cellular energy. famBlekasika. Patau syndrome : A human Patau genetic mutation caused by trisomy sheraKsBaØa ³ muytasüúgesenTicmnusS Edlbgá of chromosome 13. Individuals are severely deformed and only live eLIgedayRkUmU:sUmRTIsUmITI13. Éktþ³lUtlas;xusBIFmµtaehIyrs; for about 6 months. )anEtRbEhlCa6Exb:ueNÑaH. pathogen : Any disease-producing organism or virus. Pñak;garbgáCMgW ³ Pavrs; b¤vIrusEdlbNþaleGaymanCMgW. patroclinous inheritance : A form of genetic transmission in which tMNBUCBI)a ³ TMrg;mYyénkarbBa¢ÚnBt’manesenTic EdlkUnecAman the offspring have the phenotype of the father. epNUTIbrbs;«Buk. pectin : A gelatinous polysaccharide that makes up the biucTIn ³ b:UlIsakarItmanCatiesLaTIn EdlbgáCaPñaseRKagrbs; cell walls of diatoms. düatUem. pectoral fins : A pair of fins located laterally near the gill RBuyRTÚg ³ RBuymYyKUEdlsßitenAcMehogCitrgVHRskIrbs;RtImanfÁam. openings in all jawed fish. pectoral girdle : The part of the skeleton to which the anterior q¥wgRbvat;sµa ³ EpñkéneRKagq¥wgEdlsMrab;P¢ab;Gvyv³mux. limbs are attached. pedicel : The stalk of a flower in an inflorescence. Tgpáa ³ TgpþaenAkñúgkBa©Múpáa. pedigree : In human genetics, a diagram showing the ancestral BgSavlI ³kñúgesenTicmnusS CadüaRkambgðajBITMnak;TMng nigkar relationships and transmission of genetic traits over several bBa¢ÚnlkçN³esenTicrbs;buBVqøgkat;eRcInCMnan;kñúgRKYsarmYy. generations in a family. pedipalps : The second pair of appendages in arachnids. eCIgsÞab ³ ExñgKUTI2énGar:aKñIt. peduncle : 1. A band of white matter joining different parts of the 1- Qñab;³ bnÞHsarFatus tP¢ab;EpñkepSg²énxYrk,al. brain. 2. The stalk of a flower or of an inflorescence. 2- Tg ³ Tgrbs;páab¤kBaú©Mpáa. pelagic : A term used to describe animals that swim freely as adults stVsnøwmsmuRT ³ BaküeRbIedIm,IBN’naGMBIstVEdlEhledayesrI and live above the bottom in the open sea.. dUcstVeBjv½yEdr nigrs;enAkñúgTwksmuRTeRCA. pelagic zone : The open ocean. tMbn;snøwmsmuRT ³ tMbn;smuRTEdlsßitenAq¶ayBIRcaMg. pellicle : A thick outer protein layer surrounding the cell EBlIKul ³ RsTab;RbUetGIunRkas;enAxageRkAEdlB½T§CMuvijPñasekasika membrane of a euglena and some other protists. rbs;GWEKøn nigRbUTIsþepSgeTotmYycMnYn. pelvic fins : A pair of fins located vento-laterally in all jawed fish. RBuyeBaH ³ RBuymYyKUsßitenAsgxageBaHrbs;RtImanfÁam. pelvic girdle : The part of the skeleton to which the posterior q¥wgRkvat;RtKak ³ EpñkéneRKagq¥wgEdlsMrab;P¢ab;Gvyv³eRkay. limbs are attached.

penetrance : The percentage of individuals with a particular PaKryesNUTIbedayELk ³ PaKryénÉktþ³EdlmanesNUTIb genotype that show the associated phenotype. e.g. the dominant gene edayELkEdlbgðajBIepNUTIbEdlTak;TgnwgesNUTIb. ]TahrN_ ³ for baldness shows 100% EsnlubkMnt;k,al TMEBk bgðaj !00° elImnusSRbus b:uEnþ 0° penetrance in males but 0% penetrance in females. elImnusSRsI. penicillin : An antibiotic produced Penicilum Chrysogenum by the fungus Penicilum eb:nIsIulIn ³ Gg;TIbüÚTicEdlplitBIpSiteQµaH . chrysogenum. penis : A male reproductive organ in animals that have internal ligÁ ³ srIragÁbnþBUCeQµalrbs;stVEdlmankarbgákMenItkñúg. fertilization. pentadactyl : With five digits, manRmamR)aM pentadactyl limb : A limb structure common to amphibia, Gvyv³RmamR)aM ³ eRKagGvyv³rbs;BBYkkEgáb lµÚn bkSI nigfnikstV reptiles, birds and mammals, thought to have evolved as an EdleKKitfa)anvivtþedIm,IbnSMúaeTAnwgCIvitelIeKak. rYmman bIEpñksMxan;² adaptation to life on land. Consists k- q¥wgeTalEdlP¢ab;eTAnwgdgxøÜnEdlP¢ab;eTAnwg x-q¥wgRsbKñaBIrEdl of three main parts; a) a single bone that joins the body, which P¢ab;eTAnwg K- q¥wgtUc²mYyRkumEdlbegáIt)anq¥wgRmamR)aM. connects to b) two parallel bones, which connect to c) groups of emIlTMBr½ 321 . small bones that make up five digits. See p. 321. pentamerous radial symmetry : A type of body plan that can be sIuemRTIkaMR)aMRCúg ³ RbePTeRKagdgxøÜnEdlGacEckCaR)aMEpñkesµI²KñaBI divided into five equal parts from a central axis. G½kSkNþalmYy. ]-páaysmuRT. pentose phosphate pathway : A series of chemical reactions that clnkarb:g;tUpUsVat ³ esrIRbtikmµKImI Edlcab;epþImCamYynwg start with glucose- 6-phosphate from glycolysis and involve several KøúykUs-6-pUsVat BIkarbMEbkKøúykUs nigBIkarcUlrYménsárkabUn 5 five carbon sugars (pentoses); ¬b:g;tUs ¦mYycMnYn. kñúgdMeNIrenH NADP RtUv)anbnßymkCa NADPH during this pathway, NADP is reduced to NADPH, but no ATP is b:uEnþKµan ATP RtUv)anbegáIteT. produced. pepsin : The principal protease in the stomach. biubsIun ³ Gg;sIumRbUetGasy:agsMxan;enAkñúgRkBH. peptidase : An Enzyme that catalyzes the hydrolysis of peptide biubTIdas ³ Gg;sIumEdlCYysMrYldl;kareFVIGIuRdÚlIs ¬karbMEbk ¦ bonds in polypeptides into individual amino acids. sm<½n§biubTIt kñúgb:UlIbiubTIteGayeTACaGasIutGamIen. peptide : Compound consisting of amino acids linked by peptide biubTIt ³ smasFatuEdlmanGasIutGamIencgsm<½n§CamYyKñaedaysm<½n§ bonds. Often the number of amino acids is indicated by prefixes, such biubTIt. GasIutGamIenPaKeRcInRtÚv)anbBa¢ak;edaybuBVbTdUcCa DI- RTI- as di-, tri-, or oligo-. b¤GUlIkU-¦. peptide bond : A chemical bond that forms between the organic sm<½n§biubTIt ³ sm<½n§KImIEdlP¢ab;RkumGasIutsrIragÁrbs;Rkum acid group of one amino acid and the amino group of another amino GasIutGamIenmYyeTARkumGamInrbs;GasIutGamIenmYyeTot. acid.

peptidoglycan : A large carbohydrate polymer found in the biubTIdUKøIkan ³ b:UlIEmkabUGIuRdatd¾FMenAkñúgPñaseRKag)ak;etrI. vabgá walls of true bacteria. It is composed of long chain molecules eLIgedayRcv:ak;m:UelKuld¾EvgP¢ab;KñaeTAvijeTAmkedayRcvak;buibTItxøI². interconnected by short chains of peptide. peptidyl transferase : A type of enzyme in the large ribosomal biubTIDIlRtg;Es‘Vras ³ Gg;suImmYyRbePT enAkñúgÉktargFMrIbUsUm subunit that catalyzes the formation of a peptide bond between the EdleFVIktþalIselIkarbegáItcMNgbuibTItrvagGasuItGamIenenAcug amino acid at the end of a growing b:UlIbuibTItkMBuglUtlas; nigGasuItGamIenbnÞab;EdlRtUvbBa©ÚleTAkñúg polypeptide and the next amino acid to be added to the chain. Rcvak;. percentage composition : Percentage by weight of each ele- smasPaBPaKry ³ PaKryCama:sénFatunImYy²kñúgsmasFatuEdl ment in a compound, calculated from formula or molecular RtÚv)anKNnaecjBIrUbmnþb¤ma:sm:UelKul. vaesIµnwgcMnYnxñatm:asGatUm weights. It is equal to the number énFatuEdlmanenAkñúgrUbmnþEcknwgma:sm:UelKulsrub. of atomic mass units of the element in question present in the formula, divided by the total formula or molecular weight. perception : Recognition by the brain that a stimulus has been kardwg ³ karTTYlsÁal;edayxYrk,al enAeBlrMejacRtÚv)anTTYl. received. perennial : A plant that lives for more than two growing seasons. PWernenol ³ rukçCatiEdlrs;)anCag2rdUvlUtlas;. perfect flower : A flower having both stamens and a pistil. páarYmePT ³ páaEdlmanTaMgkBa©MúeksrjI TaMgkBa©MúeksreQµal. pericardium : A protective membrane that surrounds the heart eRsamebHdUg ³ PñaskarBarEdlB½T§CMuvijebHdUgmnusS. in humans. pericarp : Refers collectively to the layers of ovary tissue in a fruit; eBrIkab ³ sMedAeTAelIRsTab;CalikaGUEvenAkúñgEpø. eBrIkabCaBakü pericarp is the preferred term for fruits whose layers cannot be easily EdleKniymeRbIsMrab;EpøEdlRsTab;rbs;vaminGacEbgEckBImYyeTAmYy distinguished from one another. edayRsYlenaHeT. pericentric inversion : A chromosome inversion that in- cMras;eBrIsg;RTic ³ cMras;Ggát;RkUm:UsUmEdlCab;Tak;TgédTaMgBIrén volves both arms of the chromosome and thus involves the RkUm:UsUm dUecñHehIyvak¾Cab;Tak;TgCamYysg;RtUEm. centromere. pericycle : The layer of cells surrounding the xylem and phloem eBrIsIuk ³ RsTab;ekasikaB½T§CMuvijsuIELm nigpøÚEGmrbs;rwsEdlvabegáIt of roots; produces branch roots. rwsExñg. periderm : The protective tissue that replaces epidermis; includes eBrIEDm ³ CalikakarBarEdlCMnYseGBIEDm EdlrYmmanElüs¬epeLm¦ cork (phellem), cork cambium (phellogen), and phelloderm. RsTab;emeRkA¬epLÚEsn¦ nigEpLÚEDm. period : A unit of geologic time that is a subdivision of an era. sm½ykal ³ ÉktaénFrNIkal EdlCacMEnkrgrbs;s½k.

periodic table of the elements : Table in which elements are taragxYbénFatuKImI ³ taragEdlFatuKImIRtÚv)anerobtamlMdab;kMenIn arranged generally in order of ) increasing atomic number (number elxGatUm ¬cMnYnRbUtug . FatuTaMgGs;énCYredknImYy²begáIt)anCaxYb of protons). The elements of each mYyénlkçN³rUbniglkçN³KImI ehIyCYrQrmanRkúmFatuKImIEdlman row constitute one period or cycle of chemical and physical lkçN³KImIRbhak;RbEhlKña. emIlTMBr½ 332 . properties, and the columns comprise elemental families of similar chemical behavior. See p. 332. periodontal membrane : A thin layer of fibrous connective tissue PñasCMuvijeFµj ³ RsTab;Calikasn§ansrésesþIg EdlP¢ab;rwseFµj that anchors the roots of teeth to the jawbone. eTAnwgq¥wgfÁam. periosteum : A tough membrane surrounding all bones. PñasCMuvijq¥wg ³ PñassVitEdlB½T§CMuvijq¥wgTaMgGs;. peripheral cells : Outermost cells of the root cap that secrete ekasikabrimNÐl ³ekasikaRsTab;eRkAbMputénk,alrws EdlbeBa©j mucigel; they are removed from the root cap as the root grows muysIuEsl. vaRtUv)anbBa¢ÚnBIk,alrws enAeBlEdlrwsduHlUtcUl through the soil. eTAkúñgdI. peripheral nervous system : All of the neurons lying outside of the RbB½n§RbsaTbrimNÐlb¤RbB½n§RbsaTCay ³ekasikaRbsaTTaMgGs; brain and spinal cord. EdlsßitenAeRkAxYrk,alnigxYrq¥wgxñg. peristalsis : A rhythmic, muscular relaxing and contracting that clnakRnþak;CacgVak; ¬eBrIsþlsIus¦ ³ karkRnþak;nigrlaCacgVak;én moves food along the digestive tract. sac;duMedIm,IrMkilGahartambNþaybMBg;rMGahar. peristome : The “teeth” around the opening of the sporangium of eb:rIsþÚm ³ :eFµj¶¶ : enACMuvijmat;ebIkéns,:r:g;rbs;Esø. mosses. perithecium : A flask-shaped or spherical ascocarp with a terminal eBrIEts ³ GassáÚkabragEsV‘ b¤ragdUcdbEdlebIkcMhenAxagcug. opening. peritoneum : A membrane that lines the body cavity and forms the PñaseBaHevon ³ PñasB½T§CMuvijRbehageBaH nigeRsabsrIragÁTaMgLay covering of the organs in the coelom. kñúgRbehagsWLÚm. permafrost : A layer of ground in the tundra that is always frozen. kMNkdIGciéRnþy_ ³ RsTab;dIenAtMbn;TunRda EdlmanTwkkkCanic©. permanent wilting point : The moisture content of soil at the point cMNucRseBanGciéRnþy_ ³ sMeNImrbs;dIkñúgkMritmYyEdlRbB½n§rws when a particular plant’s root system cannot absorb water, even rbs;rukçCatimYyminGacRsUbykTwk)an eTaHbICaeRsacTwknigdak;enAkñúg when given water and placed in a bnÞb;esImk¾eday. humid chamber. permeable (adj) : Allowing a substance to pass through. GacRCab)an rWRCabTwk ³ EdlGaceGaysarFatuqøgkat;)an. permissive condition : Environmental conditions under l½kçx½NÐTTYlsÁal; ³ l½kçx½NÐbrisßan Edlmuytasüúgl½kçx½NÐmYy which a conditional mutation (such as a temperature sensitive mutant) ¬dUcCamuytg;EdlrYsnwgsItuNðPaB ¦sMEdgecjnUvepNUTIbRbePTéRB. expresses the wild-type phenotype.

peroxisome : A type of microbody that occurs primarily in leaves and eBr:UsIusUm ³ mIRkUsarBagÁkaymYyRbePTEdlPaKeRcInmanenAkñúgsøwk contains enzymes that metabolize hydrogen peroxide and glycolic rukçCatinwgpÞúkGg;suImEdleFVIemtabUlIsGIuRdUEsnEBGuksuIt nigGasuIt acid. KøIkUlic. perspective formula : Representation of a chemical KMnUstagrUbmnþ ³ tMNagTMrg;KImIEdlbgðajBITMrg;vimaRtbIénKMrUdMumUl structure that shows the three dimensions of a ball-and-stick nigGgát;ehIymanPaBgayRsYlkñúgkartagrUbmnþ. model and has some of the simplicity of the structural formula. pesticide : A poison used to kill pests. This term is often used fñaMsMlab;stVcéRg ³ fñaMBulsMrab;sMlab;stVcéRg. BaküenHeRcIn interchangeably with insecticide. eRbICYsKñaeTAvijeTAmkCamYyBaküfñaMsMlab;stVl¥it. petal : A brightly colored, modified leaf that surrounds the RsTab;páa ³ søwkkMENERbmanBN’PøW EdlenAB½T§CuMvijsrIragÁbnþBUCrbs ; reproductive organs of a flower. páa. petiole : The stem-like structure that connects the leaf to the stem. Tgsøwk ³ TMrg;dUcedImEdlP¢ab;søwkeTAnwgedIm. petrifaction : The changing of organic matter into stone. Also dMeNIrkøayeTACafµ ³ karpøas;bþÚrsarFatusrIragÁeTACafµ. dMeNIrenH called fossilisation. GacehA)anpgEdrfapUsuIlkmµ. PGAL (phosphoglyceraldehyde) : A three-carbon sugar that is an pUsVrKøIesra:l;edGIut ³ sárkabUn3EdlCaplitplkNþalénrsµI intermediate product of photosynthesis. sMeyaK. pH : A symbol of the relative pH concentration of hydrogen ions in a ³ nimitþrUbénkMhab;GIuyu:gGIuRdUEsnkñúgsUluysüúgmYy. solution. pH = - log[H 0+]. + 3 pH = - log[H 30 ]. . pH scale : A scale used to measure pH the concentration of hydrogen ions kMrit ³ kMriteRbIsMrab;vas;kMhab;GIuy:ugGIuRdUEsnkñúgsUlusüúgmYy in a solution and therefore its pH acidity. pH values are from 0 to 14, faetIvamankMritGasIutrW)as. tMél ERbRbÜlBI 0 eTA 14 nigenAeBl and the lower the value, the more pH kan;EtTab GasuItkan;EtxøaMg rWGIuyu:gGIuRdUEsnmankan;EteRcInkñúgenA acidic or hydrogen ions in the solution. sUluysüúg. phage : See bacteriophage. pas ³ emIl bacteriophage . phagocyte : An amoeba-like white blood cell that engulfs and destroys pakUsIut ³ eKalikasragdUcGamIb EdlelbnigkMeTcmIRkUsarBagÁkay invading microorganisms. EdleRCotcUleTAkñúgsarBagÁkay. phagocytosis : The process through which food particles are pakUsIutUs ³ lMnaMEdlbMENkGaharRtUv)anrMuB½T§edayPñasekasika nig surrounded by cell membrane and incorporated into the cell ekþabbBa©ÚleTAkñúgsIutU)aøsekasikabegáIt)anCava:KuyGUlGahar. cytoplasm, forming a food vacuole. phagotropic : Ingesting solid food particles. pakURtUBic ³ karelbcUlGaharrwgtUc². phalange : Any of the bones in pentadactyl fingers and toes. See pentadactyl q¥wgfñaMgéd rWeCIg ³ q¥wgNamYyénq¥wgRmameCIg. sUmemIl limb and p. 321. limb nigemIlTMBr½ 321 . Phanerozoic : Period since the 320 Cambrian. See p. 320. paenr:UsUGiuc ³ ry³eBltaMgBIkMRb‘Íeyogmk. emIlTMBr½ .

pharyngotremy : Condition in which the pharyngeal walls are rgV³edImk ³ sßanPaBEdlépÞedImk RtUv)anTMluHebIkdUcCargVHEdleK perforated by slit-like openings; found in chordates and RbT³eXIjcMeBaHkrednigeGmIkred. hemichordates. pharynx : 1. An extendable turbellarian muscular tube used for feeding in edImk ³ 1- cMeBaHdgáÚvxøÜnsMEb:t CabMBg;sac;dMulUt)an turbellarian flatworms. 2. An area of the throat between the mouth sMrab;cab;Gahar. 2- EpñkénbMBg;kEdlsßitenAcenøaHmat;nigbMBg; and esophagus. Gahar. phellem : Cork; produced by the phellogen. epeLm ³ RsTab;minRCabTwk EdlbegáItedayepLÚEsn. phelloderm : The inner part of the periderm; forms inside of the epLÚEDm ³ Epñkxagkñúgrbs;eBrIEDmEdlkekItenAxagkñúgepLÚEsn. phellogen. phellogen : Cork cambium. epLÚEsn ³ RsTab;ekasikaEdlbegáItekasikaFn;Twk. phenocopy : A phenotype caused by the environment (i.e. cannot be epNUTIbdUc ³ epNUTIbbNaþlmkBIktþabrisßan ¬KWfaminGactBUC inherited) which closely resembles the phenotype produced by a )an ¦EdldUceTAnwgepNUTIbEdlplitedayEsnsÁal;mYy. known gene. phenol : Any aromatic ring with an -OH –OH group is classified as a epNul ³ siucGar:Um:aTicNaEdlmanRkúm RtÚv)ancat;fñak;Ca phenol. Phenol is also the name for the simplest member of this class. epNul. epNulk_CaeQµaHrbs;FatuEdlgayCageKenAkñúgfñak;enHEdr. phenolic : Any compound that contains a fully unsaturated, epNUlic ³ smasFatuEdlpÞúkvg;kabUn6minEq¥t EdlRtUvP¢ab;eTAnwg six-carbon ring that is linked to an oxygen –containing side group. RkummçageTotEdlpÞúkGuksuIEsn. phenotype : The observable appearance of an individual as a epNUTIb ³ lkçN³EdlGacemIleXIjrbs;Éktþ³EdlCalT§plén result of its genetic makeup. sMPar³esenTicrbs;va. phenyl : Benzene ring when used as an alkyl group attached to a epnIl ³ siucbg;EsnenAeBlEdlRkúmGal;KIl)anP¢ab;CamYy larger molecule. m:UelKulmYyFMCag. phenylketonuria (PKU) : A genetic disease in which the epnIlXIfUNYero ³ CMgWesenTicEdlbNþalmkBIGvtþmanGg;sIum müa:g absence of an enzyme causes a buildup of the amino acid eFVIeGaymankarkekItGasIutGamIenepnIlGaLanIn. 90°énGñkCMgW phenylalanine. 90% of patients are manbBaØaGn;fyy:agxøaMg. severely mentally retarded. phenylpropanoid : A complex phenolic that has a three-carbon epnIlRbÚ)a:NUGIut ³ epNUlIsaMjauMmYyEdlmanRcvak;ExScMehog side chain; phenylpropanoids are generally derived from the amino kabUn3. CaTUeTAvamanRbPBmkBIGasuItGamIenepnIlGaLanIn nig acids phenylalanine and tyrosine; TIr:UsuIn. mIrIsÞIsuInEdlCaeRKOgpSMrsCatid¾sMxan;énc½n§RKw³sña (nutmeg) myristicin, the main flavor ingredient of nutmeg, is a KWCaepnIlRbU)a:NUGuIt. phenylpropanoid. pheromone : Naturally occurring compound produced by an epr:Um:Un b¤køinxøÜn ³ smasFatuEdlekIteLIgedayFmµCatinigRtUv)an organism for the purpose of chemical communication that plitedayPavrs;edIm,ITMnak;TMngKImI Edlman\T§BleTAelIGakb,kiriya affects the behavior of others of the rbs;Pavrs;epSgeTotkñúgRbePTEtmYy. ]TahrN_ ³ vaRtUv)aneRbIkñúgkar same species. eg. used to attract mates for reproduction. Tak;TajédKUedIm,IeFVIkarbnþBUC.

phloem : Vascular tissue including sieve tubes, companion cells and pøÚEGm ³ CalikasrésnaM EdlrYmmanCalikabMBg;Rbehag ekasikatam parenchyma cells, that transports food, water and organic solutes nigekasika)a:r:g;sIum EdldwknaMGahar Twk nigFaturlaysrIragÁ throughout a plant (translocation). eTARKb;EpñkTaMgGs;rbs;rukçCati ¬dMNwknaM¦. emIlTMBr½327 . See p. 327. phosphate : An ion composed of one phosphorus atom bonded to pUsVat ³ GIuy:ugEdlpSMeLIgedayGatUmpUsVrmYy P¢ab;eTAnwgGatUm four oxygen atoms. Part of a nucleotide. GuksIuEsnbYn. Epñkrbs;nuyekøGUTIt. phosphoacyl glycerols : Amphipathic molecules similar to pUsVrGasIulKøIesr:ul ³ m:UelKulGMPIpaTicEdlmanTMrg;Rbhak;RbEhl triacylglycerols in structure, but with a substituted phosphoric acid nwgRTIGasIulKøIesr:ul b:uEnþGasIutxøaj;enAelIRkúmGIuRdúksIulTIbIénKIøesr:ul in place of the fatty acid on the RtÚv)anCMnYsedayGasIutpUsVric. third hydroxyl group of glycerol. phosphodiester bond : A bond between a sugar group and a sm<½n§pUsVrDIeGEsÞ ³ Casm<½n§rvagRkumsár nigRkumpUsaVt. sm<½n§ phosphate group. Phosphodiester bonds between alternating sugars pUsVrDIeGEsÞ sßitenAqøas;KñarvagsárnigpUsVatbegáItCaTMrg;eRKagrbs; and phosphates, form the backbone m:UelKulGasuItnuyekøGuic. of nucleic acid molecules. phospholipid : A molecule composed of a lipid and a pUsVrlIBIt ³ m:UelKulEdlbgáeLIgedaylIBItnigRkumpUsVat. phosphate group. photochemical reactions : The “light” reactions of photo- RbtikmµKImIBnøW ³ RbtikmµBnøWénrsµIsMeyaK. RbtikmµenHekItmanenA synthesis. These reactions occur on ATP NADP the grana of chloroplasts and elItMbn;Pñaskør:U)aøsrbs;kør::UPIl nigbegáIt nigbnßy . produce ATP and reduced NADP. photon : Packet of light waves, sometimes called a “quantum.” hVÚtug ³ sMNMurlkBnWøEdlCYnkaleKehAfa{kg;Tum}. pg;mUldæan The fundamental particle of light. rbs;BnøW. photoperiod : The length of the light part of the day. ry ³eBlPWø ³ ry³eBlmanéf¶enAeBléf¶. photoperiodism : The response of a plant to varying periods of light vdþBnøW ³ tMNbrukçCatieTAnwgkarERbRbYlénry³eBlBnøWW nigry³eBl and darkness. ggwt. photophore : Light-emitting organ. pUtUpr ³ srIragÁbeBa©jBnøW. photo-reactivation repair : Light-induced repair of damage karCYsCuledayeRbIBnøW ³ karCYsCulénkarxUcxatedayeRbIBnøW Edl caused by exposure to ultraviolet light. Associated with an bNaþlmkBIkardak;[RtUvnwgBnøWsaVyG‘uyRta. vaTak;TgCamYyRbB½n§ intracellular enzyme system. Gg;suImxagkúñgekasika. photorespiration : The light-dependent formation of degðImBnøW ³ kMNGasuItKøIkUlicedayBnøWenAkúñgkør:U)aøs nigGuksuItkmµ glycolic acid in chloroplasts and its peroxisome subsequent oxidation in bnÞab;rbs;vakñúgeBr:UsIusUm ¬ ¦. peroxisomes. photosynthesis : A process by which plants, using energy from rsµIsMeyaK ³ dMenIrEdlrukçCatieRbIfamBlBnøWRBHGaTitü edIm,IbegáIt sunlight in the presence of chlorophyll, produce carbohydrates kabUGIuRdat ¬m:UelKulsrIragÁ ¦ BI]sµ½nkabUnic nigTwkedaymanvtþman from carbon dioxide and water. rbs;kørU:PIl.

photosystem : A complex of chlorophyll and other pigments RbB½n§BnøW ³ kMpøickør:UPIlnigCatiBN’epSgeTot EdlmanenAkñúg embedded in the thylakoids of chloroplasts and involved in the TILakUGIuténkør:U)aøs nigTak;TgkñúgRbtikmµKImIBnøW ¬]- BnøW ¦énrsµIsMeyaK. photochemical (i.e., “light”) reactions of photosynthesis. phototropism : The growth response of a plant to light. TMnajBnøw ³ tMNblUtlas;énrukçCatieTArkBnøW. phragmoplast : A set of microtubules oriented parallel to RhVakm:U)aøs ³ RkumkUnbMBg;EdlRsbeTAnwgG½kSRty:UgGaRkUm:aTic the axis of the spindle apparatus (perpendicular to the plane of cell ¬Ekgnwgbøg;cMEnkekasika ¦ EdlnwgbegáItCasnÞHx½NÐ. vaekItman division), which will form a cell cMeBaHrukçCati nigsaryébtgPaKeRcIn. plate; phragmoplasts occur in plants and in most green algae. phycobilins : Water-soluble accessory pigments occurring in PIkUb‘ÍlIn ³ CatiBN’bnÞab;bnSMEdlrlaykñúgTwk EdlmancMeBaH the red algae and cyanobacteria. sarayRkhm nigsüaNU)ak;etrI. phycocyanin : A blue photosynthetic pigment found in PIkUsüanIn ³ CatiBN’exovrsµIsMeyaKénsüaNUPIt. cyanophytes. phycoerythrin : A red photosynthetic pigment found in PIkUeGrIRTIn ³CatiBN’RkhmrsµIsMeyaKénsüaNUPItnigsarayRkhm. cyanophytes and red algae. phycoplast : A set of microtubules oriented perpendicular to the axis PIkU)aøs ³ RkumkUnbMBg;EdlEkgnwgG½kSRtyUgGaRkUm:aTic ¬Rsb of the spindle apparatus (parallel to the plane of cell division), which nwgbøg;cMEnkekasika ¦ EdlnwgbegáItCasnÞHx½NÐ. vamanEtcMeBaH will form a cell plate; phycoplasts sarayébtgmYycMnYnb:ueNÑaH. occur only in a few green algae. phyletic evolution (vertical ( vertical evolution) evolution) : The gradual karvivtþn_RbePT b¤ ³ bMErbMrYlbnþicmþg²én transformation of one species into another over time. RbePTmYyeTACaRbePTmYyeTotkúñgry³eBld¾yUr. phyllotaxis : The arrangement of leaves on a stem. hVILÚfak;sIus ³ kartMerobrbs;søwkenAelITgsøwk. phylogenetic (adj) : Relating to the development of an evolutionary énRbvtþiBUCGMbUr ³ EdlTak;TgeTAnwgkarlUtlas;énBUCGMbUrvivtþn¾. lineage. See also ontogenetic . emIl ontogenetic . phylogeny : The evolutionary his- tory of a group of organisms. RbvtþiBUCGMbUr ³ Rbvtþivivtþn_rbs;Pavrs;mYyRkum. phylum ( plural, phyla): A large group of related taxonomic classes saxa ³ RkumFMénfñak;EdlmanTMnak;TMngenAkñúgcMEnkfñak;stV. in animal classification. physical change : A change from one state of matter to another. bMErbMrYlrUb ³ karpøas;bþÜrBIsPaBmYyrbs;rUbFatueTAsPaBmYyeTot. Change that usually requires only moderate amounts of energy, is bMErbMrYlEdlCaFmµtaRtÚvkarEtbrimaNfamBllµmehIymancMras;mk reversible, and results in no change vij nig)anmkedayKµankarpøas;bþÚrGtþsBaØaNKImIénsarFatu. in the chemical identity of the substance. physical dependence : A condition in which a person’s body ejonpøÚvkay ³ sßanPaBEdlsarBagÁkayrbs;mnusSmñak;rgkar suffers physical problems when a drug is withdrawn; addiction. QWcab;EpñkrUbkayenAeBleKpþac;fñaMejon. physoclistic : Lacking a connection from the gut to the PIsUkøIsÞic ³ EdlKµankartP¢ab;BIeBaHevoneTAe)aøkxül;enAeBleBjv½y swim bladder as adults (of fishes). ¬cMeBaHRtI ¦.

physostomous : Having a connection between the swim PIsUsþÚmws ³ EdlmankartP¢ab;rvage)øakxül;nigeBaHevonenAeBl bladder and gut in adults (of fishes). eBjv½y ¬cMeBaHRtI ¦. phytochrome : A group of proteinaceous pigments involved in PItURkUm ³ RkumCatiBN’RbUetGuIn EdlTak;Tgnwg)atuPUtmYycMnYn dUcCa phenomena such as photoperiodism, the germination of vdþBnøW karduHBnøk¬RKab; ¦ nigkarbegáItsøwk. vaRsUbykBnøWBN’Rkhm seeds, and leaf formation; absorbs nigRkhmRsal. red and far-red light. phytoplankton : Tiny photosynthetic organisms that float bøg;tugrukçCati ³ Pavrs;rsµIsMeyaKtUc²EdlGENþtenAelI b¤CitépÞTwk. on or near the surface of a body of water. pi bond ( πππ-bond) : Bond formed πππ p by overlap of unhybridized p sm<½n§ ³ sm<½n§EdlekIteLIgedaykarRKbelIKñaénGrb‘Ítal;minGIuRb‘Ít orbitals of two adjacent atoms. No rbs;GatUmBIrenAEk,rKña. sm<½n§πππminGacmanelIsBIBIreT rvagGatUm more than two pi bonds can exist between two adjacent atoms. BIrCab;Kña. pigment : Any substance that reflects or absorbs light to give CatiBN’ ³ sarFatuEdleFVIeGaymankarCHRtlb;vij rWRsUbBnøWedIm,I color. pþl;BN’. piloerection : Contraction of muscles attached to hair follicles karbHeram ³ kark®nÞak;sac;duMEdlP¢ab;nwgKl;eram eFVIeGayeram resulting in the erection of the hair shafts. bHeLIg. pilus (plural: pili) : A minute tube between two bacterial cells, PIlws ¬Bhu> PIlI ¦ ³ bMBg;qµarmYyenAcenøaHekasika)ak;etrIBIrEdlCa through which transfer of genetic material may occur. Often kEnøgsMrab;epÞrsMPar³esenTic. CaFmµtamanTMnak;TMngCamYyekasika associated with cells possessing F Edlmanktaþ F . factors. pineal eye : A small vestigial eye in one species of reptile. sñamEPñk ³ sñamEPñktUcmYyénRbePTmYyrbs;lµÚn. pinnate venation : A type of venation in which smaller veins RTnugsñit ³ RbePTtMerobRTnugsøwk EdlRTnugtUc²EbkEmkecjBI branch off one main vein. 329 See p. 329. RTnugFMmYy. emIlTMBr½ . pinnately compound : A type of leaf in which the leaflets attach søwksñitrYm ³ RbePTsøwkEdlkUnsøwkP¢ab;eTAnwgTgsøwkem. emIlTMBr½ separately to the petiole. 329 See p. 329. . pinocytosis : The process by which a cell engulfs some BINUsIutUs ³dMeNIrEdlekasikaelbykm:UelKulxøHEdlrlaykñúgTwk. molecules dissolved in water. pioneer community : The first organisms to inhabit a specific shKmn_dMbUg ³ Pavrs;Edlrs;enAkñúgtMbn;mYymuneKbg¥s;. environment. pioneer organisms : The first organisms in the successional Pavrs;dMbUg ³ Pavrs;dMbUgkñúgdMeNIrpøas;eTArs;enAkEnøgfµI. process. piscivorous (adj) : Fish-eating. sIuRtI pistil : See carpel. kBa©MúeksrjI ³ emIl carpel . pistillate flower : see Carpellate. Carpellate Flower Flower páajI ³ emIl . pistillate plant : see Carpellate Carpellate Plant Plant. rukçCatijI ³ emIl .

pith : Parenchyma tissue in the center of a stem; located interior to bNþÚl ³ Calika)a:r:gsuImenAcMkNþaledIm ehIysßitenABIkñúg the vascular bundles. )ac;srésnaM. pituitary gland : A small endocrine gland at the base of the RkeBjGIub:UPIs ³ RkeBjbeBa©jkñúgtUcmYysßitenAxageRkamxYrk,al brain that secretes hormones affecting all other endocrine EdlbeBa©jGrm:Unman\T§iBleTAelIRkeBjbeBa©jkñúgepSgeTotTaMg glands. Gs;. pK : Logarithm of the acid a pH ionization constant. The pK is the efrGasIut ³ LÚkarIténefrGIuy:ugkmµGasIut.efrGasIutCa sUluysüúg solution pH at which the acid transfers a hydrogen ion. EdlGasIutmanbenÞrGIuy:ugGIuRdÚEsn. placenta (plural, Placentae ) : placentae 1. An organ in the uterus that suk ¬Bhu> ¦ ³ 1- srIragÁenAkñúgs,Ún EdldMeNIrkarpøas;bþÚr exchanges materials between the mother and fetus. 2. The area sarFaturvagmþaynigKP’. 2- kEnøgEdlGUvulRtUvP¢ab;enAkñúg inside a carpel where the ovules are kBaú©MeksrjI. attached. placental mammal : A mammal that nourishes developing young fnikstVmansuk ³ fnikstVEdlciBa©wmKP’tamry³suk. through the placenta. placoid scales : A small, spiny type of scale found in sharks. Rska)øakUGIut ³ RbePTRskatUcmanbnøaEdlmancMeBaHRtIqøam. Planck’s law : Mathematical Planck statement relating energy and c,ab; ³ sMNMuelxKNitEdlTak;TgeTAnwgfamBlnigeRbkg; frequency of electromagnetic radiation: the greater the frequency énkar beBa©jkaMrsµIeGLicRtÚm:aejTic KWeRbkg;kan;EtFM ¬BnøWBN’kan;Et (and the bluer the color of light), exov ¦enaHfamBlk¾kan;EtFMEdr ³ E = hv . the greater the energy: E = hv. plankton : Animals (zooplankton) and unicellular algae bøg;tug ³ bøg;tugstVnigbøg;tugrukçCatiEdlmanlT§PaBbMlas;TIkMNt; (phytoplankton) that have only limited ability to move and are nigRtUv)anbBa¢ÚnBIkEnøgmYyeTAkEnøgmYyeTotedayclnaTwk. therefore spread by water eRbobeFobCamYy nekton . movements. Compare nekton. planula : A ciliated larval type found in coelenterates. )øanuLa ³ RbePTkUnjas;Edlmaneramj½rénsWLg;eter. plaque : A clear area on an otherwise opaque bacterial ‘lawn’ pøak ³ tMbn;PøWenAelIfñalciBaVwm)ak;etrIRsGab;EdlbNþalmkBIkar caused by the growth and reproduction of phages. lUtlas; nigkarbnþBUCrbs;pas. plasma : The fluid portion of blood that carries blood cells. )øasµa ³ Epñkravrbs;QamEdldwknaMeKalikaQam. plasma membrane : The outer boundary of a cell separating it Pñasekasika b¤PñassIutU)aøs ³ PñasxageRkAekasikaEdlx½NÐEck from the environment; cell membrane. vaBImCÄdæanCMuvij. plasmid : A small circular piece of ADN DNA found in bacteria. Because of )aøsµúIt ³ m:UelKul CargVg;mUltUcmYysßitenAkñúg)ak;etrI. eday their ability to take up foreign ADN DNA, bacterial plasmids are used sarEtBYkvamanlT§PaBTTYlyk BIxageRkA )aøsµIt)ak;etrIRtUv as vectors for genetic engineering )aneRbICaviucT½rkñúgvisVkmµesenTic nigkarRsavRCav. and research. plasmodesma (pl. Plasodesmata plasmodesmata) : A tiny, )øassµÚedsµa ¬Bhu> ¦ ³ cg¥ÚrPñastUcmYy sßitenAcenøaH membrane-lined channel between adjacent cells. ekasikaEdlenACitKña.

plasmodium : A large mass of Slime multinucleate cytoplasm found in )aøsµÚdüÚm ³m:assIutU)aøsEdlmanéNVy:UeRcInénekasikapSit acellular slime molds. molds . plasmolysis : Loss of turgor pressure in plant cells due to loss )aøsµÚlIs ³ kar)at;bg;sMBaFe):agkñúgekasikarukçCati EdlbNþalmkBI of water. kar)at;bg;Twk. plastid : A type of organelle that is bounded by a double membrane )aøsÞIt ³ FatuekasikamYyRbePT EdlB½T§CMuvijedayPñasBIrCan; and is associated with different pigments and storage products; nigsßitenACamYynwgCatiBN’epSg² nigplitplbMrug. kør:U)øasman chloroplasts are green, BN’ébtgCa)aøsµItEdleFVIrsµIsMeyaK cMEnkÉGamILÚ)aøsCa)aøsµItbMrug photosynthetic plastids; amyloplasts are storage plastids EdlmanpÞúknUvGamIdug. that contain starch. plastron : The lower or ventral shell of a turtle. sñÚkeBaH ³ sñÚkEdlsßitenAxageRkam b¤ xageBaHrbs;GeNþIk. : Theory of Earth history in which the lithosphere is RTwsþIclnaEpndI ³ RTwsþIénRbvtiþEpndI EdlsMbkEpndIkMBugEtkekItCa continually being generated from the underlying core at specific bnþbnÞab;BIRsTab;xageRkaméntMbn;NamYy nigRtÚv)anRsÚbcUleday areas and reabsorbed into the core RsTab;dIxagRkamepSgeToteFVIeGaymanclnapÞaMgdICaes‘rInaMTVIbBIkEnøg at others resulting in a series of conveyor-like plates which carry mYyeTAkEnøgmYyeTotelIépÞEpndI. the continents across the face of the Earth. platelet : Blood cell fragments involved in clotting. )aøEkt ³ ekasikaQamEdlcUlrYmkñúgkMNkQam. pleiotropy : The multiple effects that a gene may have on the ebøGURtÚPI ³ \T§iBlCaeRcInEdlEsnGacmaneTAelIepNUTIbrbs; phenotype of an organism. Pavrs;mYy. plesiomorphic : An ancestral (“primitive”) character state. epøsüÚm:rPic ³ sPaBlkçN³buBV ¬Can;edIm ¦. plesiosaur : A long-necked, marine reptile of Mesozoic times. ebøsIuy:Us½r ³ lµÚnsmuRTkEvg sßitenAs½kemsUsUGuic. pleura : A double membrane surrounding the lungs. eRsamsYt ³ PñasBIrCan;EdlB½T§CMuvijsYt. pleurotremate : Having the main gill openings on sides of the body ePøIr:UERtm ³ EdlmanrgVHRskIenAcMehogxøÜn xagmuxRBuyRTÚg anterior to the pectoral fins as in hypotremate sharks. See also hypotremate . dUcCaRtIqøam. emIl . plexus : A network, especially of nerves or of blood vessels. dulsrés ³ bNþajsrésRbsaT rWsrésQam. ploidy : Term referring to the basic chromosome set or to multiples of bøÚGuIDI ³ BaküEdlsMedAeTAelIRkumRkUm:UsUm b¤BhuKuNénRkumenaH. that set. e.g. the ploidy of normal 2n humans is two and is written 2n. ]TahrN_ ³ bøÚGuIDIénmnusSFmµtaKWBIr nigRtUvsresr . plum pudding model : An old model of the atom that described KMrUsg;xüaEpøRBÚn ³ KMrUcas;énGatUmEdlBN’naGMBIkartMerobeGLic- the arrangement of electrons .They thought electrons were evenly Rtug. eKKitfaeGLicRtúgRtÚv)anBRgayesµIKñaenAkñúgGatUm dUcCacMNit scattered inside the atom like the EpøeQIkñúgnM (Plum pudding )b¤RsedogKñanwgkartMerobrbs;RKab;B’NexµA pieces of fruit inside a cake(Plum pudding). The arrangement of enAkñúgEpøRskanaK. black seeds inside dragon fruit is similar.

pneumatophor : 1. Upward- growing roots of some plants that PñWm:atUpr ³ 1- rwsduHeLIgeTAelIrbs;rukçCatimYycMnYn EdlduHenA grow in swamps; contain much aerenchyma and function in gas tMbn;valPk;l,ab;. vamanEG‘rr:g;suImCaeRcInEdlmannaTIkñúgkar exchange. 2. Air bladder or float pøas;bþÚr]sµ½n . 2- fg;xül; rWeBagxül;énsIupUNUpr. in siphonophores. poikilotherms (ectotherms) : Animals with a variable body stVGefrkMedA ³ stVEdlmansItuNðPaBsarBagÁkayERbRbYleTAtam temperature that changes with the external environment. sItuNðPaBénmCÄdæanxageRkA. point mutation : A mutation in which one base replaces another in muytasüúgcMnuc ³ muytasüúgEdl)asmYyRtUv)anCMnYseday)as the DNA chain. mYyTotenAkñúgRcvak; ADN . polar body (polar nucleus) : A small haploid cell resulting from eKalikab:Ul ¬éNVy:Ub:Ul¦ ³ekasikaGabøÚ:GIutEdl)anmkBIkarEck unequal cytoplasmic division during oogenesis, that does not sIutU)aøsminesµIKñakñúgkMLúgeBlkMnkaEm:tjI ehIyEdlminlUtlas;eTACa develop into a functional ovum. GUvuleBjeljeT ¬Kµanmuxgar ¦. polar covalent bond : Shared or covalent bond in which electrons sm<½n§kUv:aLg;b:UEl ³ sm<½n§kUv:aLg;EdleGLicRtúgdak;rYmminesIµKña. are shared unevenly. For purposes of definition, bonds are considered kñúgn½yenHsm<½n§RtÚv)ancat;TukfamanlkçN³b:UElrkalNaplsgkMrit to have polar properties when the eGLicRtUGviC¢manesIµnwg 0.5 b¤FMCag. electronegativity difference is equal to 0.5 or greater. polar fiber : A spindle fiber that kinetochore does not bind to a kinetochore srésb:UEl ³ srésRty:UgEdlmincgP¢ab;eTAnwg . polar molecule : A molecule with an unbalanced charge distribution. m:UelKulb:UEl ³ m:UelKulEdlmankarEckbnÞúkminesµIKña. polar nuclei : Two haploid nuclei within the ovule of an angiosperm éNVy:Ub:Ul ³ éNVy:UGabøÚGIutBIrsßitenAkñúgGUvulrbs;Gg;süÚEs

pollen tube : An extension of the pollen grain through which sperm bMBg;lMGg ³ ExñgbMBg;énRKab;lMGg EdléNVy:UkaEm:teQµaleFIV nuclei travel to the egg. dMeNIreTArkkaEm:tjI. pollination : The transfer of pollen to the female reproductive dMeNIrlMGg ³ karnaMlMGgeTATMrg;bnþBUCjI. structures. pollination droplet : A sticky exudate at the mouth of the dMNk;dMeNIrlMGg ³ sarFatus¥it EdlecjBImat;mIRkUBIlénGUvulrbs; micropyle of a gymnosperm ovule; pollen grains catching in it are rukçCatisuImNUEs

polygonum-type embryo sac development : A type of embryo karlUtlas;fg;GMRb‘Íy:ugEbbb:UlIkUn ³ RbePTénkarlUtlas;fg; sac development from a functional megaspore that forms eight free GMRb‘Íy:ugBIemkas,:muxgarEdlbegáItéNVy:UesrI8 kñúgenaH3kaøyCaFatubgá nuclei, three of which become an rbs;kaEm:tjI nig2køayCaéNVy:Ub:Ul ehIy2epSgeTotkøayCaekasika egg apparatus, two of which are polar nuclei, and two of which Gg;TIb:Ut. become antipodal cells. polymer : A molecule consisting of many identical or similar b:UlIEm ³ Cam:UelKulEdlmanpÞúknUvm:UNUEmrdUc²Kña b¤Rsedog²KñaCa monomers linked together by covalent bonds. eRcIn P¢ab;Kñaedaysm<½n§kUv:aLg;. polymerase chain reaction (PCR) : A procedure by which free RbtikmµRcvak;b:UlIEmr:as ³ viFIEdlkñúgenaHnuyekøGUTItesrIRtUv)anpÁMú nucleotides are assembled into a nucleic acid chain in a test tube by KñaCaRcvak;GasuItnuyekøGiucmYyenAkñúgbMBg;sakedayeFVIeGayskmµPaB enabling the activity of a bacterial ADN b:UlIEmr:asrbs;)ak;etrIGacP¢ab;Kña. RbtikmµenHman30vdþb¤eRcIn DNA polymerase to bind them together; the PCR is cycled 30 or Cag edIm,IbegáIttMNlMdab; ADN eKaledA)anmYylan. more times to produce a million-fold amplification of the target DNA sequence. polymerases : The enzymes that ADN catalyze the formation of DNA b:UlIEmra:s ³ Gg;suImEdlCMrujkarbegáIt ecjBIedGuksuInuy- from deoxynucleotides and RNA ARN from ribonucleotides. ekøGUTIt nig ecjBIrIbUnuyekøGUTIt. polymorphism : The existence of two or more separate phenotypes in BhusNæan ³ karelcecjepNUTIbepSg²KñaeRcInb¤eRcInkñúg a population. b:UBuyLasüúgmYy. polynomial : An expression made of several parts. BhuFar ³ karEsþgecjEdlbgáeLIgedayeRcInEpñk. polyp : A vase-shaped sessile body form found in coelenterates. b:UlIb ³ TMrg;sarBagÁkayKµanbMlas;TImanragdUcfUénsWLg;eter. polypeptide : A molecule consisting of many joined amino b:UlIbiubTIt ³ mU:elKulEdlekIteLIgBI;GasuItGamIenCab;²KñaCaeRcIn acids, not as complex as a protein. EtminsaMjaMudUcRbUetGIuuneT. polyphyletic : A taxon that does not contain the most recent b:UlIPIelTic ³ ÉktaéncMENkfñak;EdlKµanbuBVrYmfµICageKénRbePT common ancestor of all the subordinate taxa of the taxon. eRkayeKTaMgGs; rbs;ÉktacMENkfñak;. polyploidy : A condition in which n cells contain multiple sets of bU:lIbøÚGIuDI ³ sßanPaBEdlekasikamaneRcIn RkÚm:UsUm. chromosomes. polyribosome : See polysome. b:UlIrIbUsUm ³ emIl b:UlIsUm (polysome ) . polysaccharide : A carbohydrate composed of many b:UlIsakarIt ³ kabUGIuRdatbgáeLIgedayÉktamU:NUsakarItCaeRcIn monosaccharide units, such as glycogen, starch, and cellulose. dUcCaKøIkUEsn GamIdugnigEsluyLÚs. polysome : A group of several ARN ribosomes attached to a strand of b:UlIsUm ³ RkumrIbUsUmeRcIn EdlP¢ab;eTAnwgRcvak; naMsarmYy. messenger-RNA.

polytene chromosome : A ADN chromosome that has undergone RkUm:UsUmb:UlIEtn ³ RkUm:UsUmEdleFVIkarsV½ytMelIgeTV eRcIndg DNA replication several times without separation of the replicated edayKµankarpþac;ecjBIKñaénRkUm:UsUmsV½ytMelIgeTVEdlbegáIt)anCa chromosomes, forming a giant, RkUm:UsUmRkas;FMmYyedaymanRkUm:UEmtMerobKñabegáIt)anlkçN³ragCa thick chromosome with aligned chromomeres producing a bnÞ³. characteristic banding pattern. polyunsaturated : A term used to describe an organic molecule b:UlIminEq¥t ³BaküeRbIsMrab;BN’naBIm:UelKulsrIragÁmYyEdlmansm<<½n§ having more than two double bonds and having less than the BIrCan;elIsBIBIrnigmancMnYnGatUmGIuRdUEsnticCagcMnYnEdlx

positive beta decay (positron emission) : Radioactive decay karbMEbkebtaviC¢manb¤karbeBa©jb:UsIuRtúg ³ karbMEbkviTüúskmµ involving emission of a positron. The daughter product of positron EdlTak;TgeTAnwgkarbeBa©jb:UsIuRtúg. plitplrgénkarbMEbkb:UsIuRtúg decay has one fewer proton and manRbÚtugmYyticCagnigNWRtúgmYyeRcInCagGIusUtUbem. one more neutron than the parent isotope. positive effector : Small molecule whose binding to an allosteric eGpicT½rviC¢man ³ m:UelKultUcEdlP¢ab;eTAnwgGg;sIumGaLÚesþric enzyme causes an increase in enzymic activity. ehIyeFVIeGaymankMenInskmµPaBGg;sIum. positive tropism : A growth response toward a stimulus. TMenarviC¢man ³ tMNblUtlas;eq

premolar : A flat tooth located next to the canines that is used for fÁamtUc ³ eFµjsMEb:tsßitenAbnÞab;BIeFµjcgáÚmEdlmanmuxgarxaMkMeTc. grinding. preprophase band : A band of microtubules that surrounds the RkumkUnbMBg;buerRbUpas ³ RkumkUnbMBg;enACMuvijekasika EdlenACab;BI cell just beneath the plasma membrane. eRkamPñassIutU)aøs. pressure potential : The component of water potential b:Utg;EsülsMBaF ³ Fatubgáb:Utg;EsülTwk EdlbNþalmkBIkMlaMg caused by the force created by turgor pressure against a sMBaFe)a:gTl;nwgPñas. membrane. pressure-flow hypothesis : The idea that food is transported smµtikmµlMhUrsMBaF ³ KMnitEdlfaGahardwknaMtampøÚEGmekIteLIg through the phloem as a result of differences in pressure. )anedaysarPaBxusKñaénsMBaF. prey : An organism captured, killed, and eaten by a predator. rMBa ³ stVEdlRtUv)ancab; sMlab;nigsIuedaystVrMBa. prezygapophysis : Articulating surface on the anterior face of a épÞsnøak;mux ³ épÞsnøak;EpñkxagmuxénFñÚRbsaT. neural arch. prezygotic isolation mechanism : Factors that reduce inbreeding by clnkarpþac;munsuIkUt ³ ktþaEdlbnßykarbgáat;Cit eday preventing courtship, mating, or fertilization. Tb;sáat;mineGaymankarBak;Kñab¤karbgákMenIt. Pribnow box : A 6-bp sequence in Pribnow prokaryotic promoter genes that is RbGb; ³ tMnlMdab;Edlman 6KU)askñúgEsnRbUm:UT½r required for initiation of transcription. The consensus RbUkarIy:Ut EdlRtUvkarsMrab;karcab;epþIménkarcMlgRkm. tMnlMdab; sequence for this box is TATAAT. CaTUeTAsMrab;RbGb;enH KW TA TA AT . primary carbon : Carbon atom that is bonded to only one other kabUnfñak;mYy ³ GatUmkabUnEdlRtÚv)anP¢ab;eTAnwgkabUnepSgeTotEt carbon. mYyKt;. primary carnivores : Carnivores that eat herbivores and are mMsasITI1 ³ mMsasIEdlsIustVsIuesµA dUecñHvasßitenAkñúgkMritGahar therefore on the third trophic level. TI3. primary cell wall : The part of a cell wall that is laid down when the PñaseRKagTI1 ³ EpñkénPñaseRKag EdlRtUvbegáIteLIgenAeBlEdl cell is formed and expands as it grows. ekasikakekIt nigrIklUtlas;. primary consumers : Organisms that feed directly on GñkeRbIR)as;TI1 ³ stVEdlsIurukçCatiedaypÞal; b¤ehAfastVtiNasI. plants-herbivores. primary growth : The proliferation of meristematic tissue TMhMTMhat;TI1 ³ karlUtlas;y:agrh½sénemCalikaEdleFIVeGay that adds length to a root. rwslUtkan;EtEvg. primary oocyte : A cell that I : I II divides in meiosis 1 to produce the GUvUsIutTI ekasikaEdleFIVcMEnkenAemy:Us edIm,IbegáItGUvUsIutTI secondary oocyte and the first I polar body. nigeKalikab:UlTI . primary pit-field : A thin area in a cell wall where clusters of tMbn;ptTI1 ³ épÞesþIgenAkñúgPñaseRKagekasika EdlCakEnøgEdlRkum plasmodesmata occur. )aøsµÚEdsµaekItman. primary protein structure : The sequence of amino acids in a RbUetGuInTMrg;TI1 ³ tMnlMdab;énGasuItGamIenkñúgRcvak;b:UlIbuibTIt. polypeptide chain.

primary RNA transcript : A ARN ARN GTP molecule of RNA that includes the cMlgRkmdMbUg ³ m:UelKul EdlrYmmank,al GTP cap, the leader sequence, the A gene sequence, the trailer tMNlMdab;em lMdab;Esn lMdab;elIs nigknÞúyb:UlI . sequence, and the poly-A tail. primary sex ratio : Ratio of males to females at fertilization. smamaRtePTTI1 ³ smamaRtrvageQµalnigjI enAeBlbgákMenIt. primary spermatocyte : A cell I : I that divides in meiosis I to produce Es

proband : See propositus . RbUebn ³ emIl propositus . probe : In genetic research, a ADN sequence of radioactive DNA or RbUb ³ enAkñúgkarsikSaRsavRCavesenTic CatMNlMdab; viTüúskmµ RNA that is used to find the ARN complementary sequence of a gene b¤ EdleRbIsMrab;EsVgrktMNlMdab;bMeBjénEsnEdleKcg;)an of interest in a culture of clones or enAkñúgkøÚnbNþúH rWkñúgekasika. cells. proboscis : A tubular extension at the anterior of an animal, generally Rbemay ³ EpñklyragCabMBg;EvgenAEpñkxagmuxrbs;stV CaTUeTA used for locomotion or food collection; may or may not be RtUv)aneRbIR)as;sMrab;bMlas;TI rWRbmUlykGahar GactP¢ab;pÞal; directly connected to the gut. rWmiinGactP¢ab;;pÞal;eTAnwgbMBg;rMlayGahar. procambium : A meristem that produces the primary vascular RbÚkMbüÚm ³ emCalikaEdlplitCalikasrésnaMTI 1. tissues. procaryote : See prokaryote. RbÚkarIy:Ut ³ emIl prokaryote . producer : An autotrophic organism ( that manufactures its Gñkplit ³ Pavrs;sV½yCIB ¬EdlplitGaharedayxøÚnÉg ¦. Gñkplit own food ); producers form the base of food chains in an begáItmUldæanRcvak;GaharenAkñúgzanRbB½n§mYy. ecosystem. product : A substance resulting from a chemical reaction. GgÁFatukekIt / plitpl ³ sarFatuEdlTTYl)anBIRbtikmµKImI. product law : The law which says that the probability of two c,ab;plit ³ c,ab;Edlniyayfa RbU)ab‘ÍlIeténRBwtþikarN_ÉkraCüBIr independent events occurring simultaneously is the product of EdlekIteLIgenAeBlCamYyKañ CaplitplénRbU)ab‘ÍlIetÉkraCürbs;va. their independent probabilities. productivity : The rate at which an ecosystem can accumulate new plitPaB ³ GRtaEdlzanRbB½n§GacbegáInrUbFatusrIragÁfµI. organic matter. progenesis : Accelerated development of reproductive RbUsWENs ³ karlUtlas;ya:grh½sénsrIragÁbnþBUC eFobeTA organs relative to somatic tissue, leading to paedomorphosis. nwgCalikalUtlas;EdlnaMeTAdl;eb:dUm:rpUs. progeny : The offspring produced from a mating. kUnecA ³ kUnEdlekItecjBIkarbgáat;BUC. progesterone : A female sex hormone secreted by the corpus RbÚesesþr:Un ³ GrmU:nePTjIEdlbeBa©jedayGgÁFatuelOgnigsuk Edl luteum and the placenta; prepares the uterus for the fertilized egg and manmuxgarerobcMs,ÚneRtomTTYls‘utbgákMenIt nigrkSasmtßPaBs,Ún maintains the capacity of the uterus kñúgkarRTRTg;GMRb‘Íyu:gnigKP’. to hold the embryo and fetus. proglottid : A segment of a tapeworm. kg; ³ kg;rbs;dgþÚvxøÚnsMEb:t. progymnosperms : A group of extinct plants believed to be the buBVsuImNUEs

prolactin : A hormone secreted by the anterior pituitary that stimulates RbÚLak;TIn ³ Grm:UnbeBa©jedaykMBkmuxGIub:UPIsEdlePJacRkeBj the secretion of milk from the mammary glands. TwkedaHeGaybeBa©jTwkedaH. promoter : A region of DNA at ADN the beginning of each gene, just RbÚm:UT½r ³ tMbn;mYyrbs; enAkEnøgcab;epþImEsnnImYy² enACab;BI ahead of an initiator code. muxRkmcab;epþIm. prop root : A root that comes out of a stem above the soil and rwsRBeyag ³ rwsduHecjBIedImEdlRTRTg;rukçCati. supports the plant. prophage : A phage genome integrated into a bacterial RbÚpas ³ esNUmrbs;pasEdlRtUv)anbBa©ÚleTAkñúgRkUm:UsUmrbs; chromosome. Bacterial cells carrying prophage are called )ak;etrI. ekasika)ak;etrIEdlpÞúkRbUpasehAfalIsUEsnI. lysogenic. prophase : The first stage of I mitosis in which the chromosomes RbÚpas b¤vKÁTI ³ dMNak;kalTI1énmItUsEdlRkUm:UsUmrYjxøI nig contract and the spindle forms. srésRtyUgGaRkÚma:TickekIteLIg. prophase I : The first prophase of I I I meiosis; in prophase I, homologous vKÁRbÚpas ³ RbUpas énemy:Us. kñúgvKÁRbUpas enH RkUm:UsUm chromosomes condense, synapse, cross over, and desynapse; GUm:ULÚkeLIgRkas; P¢ab;Kña RkUsuIjGUevI nigpþac;BIKña. küasµaeFVIdMeNIreTA chiasmata move to the ends of kan;xagcugRkUm:UsUmenAcugvKÁenH. emIl leptotene, zygotene, pachytene, chromosomes by the end of prophase I. See leptotene, diplotene, diakinesis . zygotene, pachytene, diplotene, diakinesis. prophase II : The second prophase II II of meiosis; in prophase II, vKÁRbÚpas ³ RbUpasTIBIrénemy:Us. kñúgvKÁRbUpas enH chromosomes condense, the nuclear envelope disintegrates, and RkUm:UsUmeLIgRkas; PñaséNVy:Urla ehIysrésRtyUgGaRkUm:aTicRbmUl a spindle apparatus is assembled; pþMúKña . cMeBaHPavrs;PaKeRcIn KµanvKÁRbUpas II enHeT ebIKµanetLÚpas I. in many organisms, prophase II is bypassed if telophase I is also kñúgkrNIenHéNVy:Uemy:UsdMeNIrkarpÞal;BIGaNapas I . bypassed, in which case the meiotic nuclei go directly from anaphase I. propositus (female ) : An individual considered as the RbUb:UsuITus ¬jI ¦ ³ Éktþ³mYyEdleKKitfa CacMnuccab;epþImsMrab; starting point for a study of the inheritance of a particular karsikSaBItMnBUCénlkçN³BiesskñúgGMbUrmYy. b¤GacehAfaRbUbg;. characteristic in a family. Also known as a proband. prosimian : Any of a group of lorises, lemurs primitive primates including RbUsIuemJóg ³ RkumRBIm:atCan;edImEdlrYmmansVa nig lorises, lemurs, and tarsiers. tarsiers . prostaglandin : Regulatory lipids derived from unsaturated fatty RbÚsþakøg;DIn ³ lIBItkMEntMrUvEdl)anmkBIGasIutxøaj;minEq¥t nigRtUv acids, produced in a cell that mediates hormonal action. Their )anplitenAkñúgekasikaEdlCMrujskmµPaBGrm:Un. \T§iBlsMxan;bMput most important effect is to enhance rbs;vaKWkarCMrujvdþ AMP . cyclic AMP. prostate, prostate gland : A gland in male animals that produces RkeBjRbUsþat ³ RkeBjrbs;stVeQµal EdlplitsarFatumüa:g substances which are added to 322 semen. See p. 322. EdlbEnßmeTAkñúgTwkkam. emIlTMBr½ .

prosthetic group : Group in a protein that is not an amino acid RkúmRbÚesþTic ³ RkúmkñúgRbÚetGIunEdlminEmnCaGasIutGamIenehIyman and that plays a major role in the activity of conjugated proteins. eg. tYnaTIsMxan;kñúgskmµPaBénRbÚetGIunqøas;. ]TahrN_ ³ RkumeGmmanEdk the iron-containing haem group EdlRtUv)anP¢ab;eTAnwgeGm:UkøÚb‘Ín. that is attached to haemoglobin. protandric hermaphroditism : A pattern of sexuality in which a rYmePTeQµalmun ³ KMrUbnþBUCedayePTEdlÉktþ³mYymanmuxgarCa single individual functions as male and then female in sequence. eQµalnigbnÞab;mkmanmuxgarCajI. protandrous ( adj. protandric) : The situation when male gametes EdleBjv½ymun ³ sßanPaBEdlkaEm:teQµaleBjvy½munkaEm:tjI. mature before female gametes. protease : Enzymes that catalyze the hydrolysis of peptide bonds in RbÚetGas ³ Gg;sIumEdlkatalIsGIuRdÚlIssm<½n§biubTItkñúgRbÚetGIun proteins and polypeptides. eg. pepsin, trypsin, erepsin, renin. nigb:UlIbiubTIt. ]TahrN_ ³ biubsiun RTIbsIun eGrIbsIun ernIn. protease inhibitor : Any chemical that inhibits the activity of Gñkbg¥ak;RbUetGas ³ sarFatuKImINaEdlraraMgskmµPaBrbs;Gg;suIm enzymes that digest proteins (i.e., proteases); protease inhibitors can bMEbkRbUetGuIn ¬]/ RbUetGas ¦. Gñkbg¥ak;RbUetGask¾GacCaRbUetGIunpg also be proteins. Edr. protein : A macromolecule made of amino acids bonded together by RbÚetGIun ³ m:aRkÚm:UelKulEdlbgáeLIgedayGasIutGamIenCaeRcIntP¢ab; peptide bonds, that have important primary roles in living systems. See Kñaedaysm<½n§biubTIt nigmantYnaTIsMxan;kñúgRbBn§½CIv³. emIl primary protein structure, protein structure, secondary protein structure, tertiary protein structure, secondary protein structure, quaternary protein structure . tertiary protein structure, quaternary protein structure. protein synthesis : The process ARN ARN whereby the tRNA utilizes the sMeyaKRbUetGIun ³ dMeNIrEdl dwknaMeRbI naMsar CaGñknaM mRNA as a guide to arrange the amino acids in their proper pøÚvkñúgkartMerobGasIutGamIentamlMdab;RtwmRtUveTAtamBt’manesenTic sequence according to the genetic kñúgRkmKImIrbs;ADN . information in the chemical code of DNA. proteinoid : The protein-like structure of branched amino acid RbUetGIuNUGIut ³ TMrg;dUcRbUetGIunénRcvak;GasIutGamIenEbkExñgEdlCa chains that is the basic structure of a microsphere. TMrg;RKwHrbs;mIRkÚEsV‘. protein-sparing : The conservation of proteins by first RbUetGIunbMr:ug ³ karrkSaRbUetGIun EdldMbUgeFVIGuksIutkmµkabUGIuRdat oxidizing carbohydrates and fats as ATP a source of ATP energy. nigxøaj; edIm,IeFVICaRbPBfamBl . Proterozoic : Later part of the Precambrian, from about 1.5 RbUetr:UsUGiuc ³ sm½ykalBIcugbuerkMRb‘ÍeyogEdlmanGayu1500ekadiqñaM billion years ago until the beginning of the Cambrian 500 rhUtdl;edImkMRb‘Íeyog EdlmanGayu 500 lanqñaM. million years ago. See also emIl Phanerozoic nigemIlTMBr½ 320 . Phanerozoic, and p. 320. prothallial cells : Two of the four cells produced during the ekasikaRbÚtal; ³ ekasikaBIrkñúgcMeNambYnEdlRtUv)anbegáItenAkñúg development of a gymnosperm microspore into a pollen grain. The ry³eBlénkarlUtlas;rbs;mIRkUs,:sIumNUEs

prothallus : Small algae-like psilopsids gametophyte in psilopsids and RbÚtal; ³ kaEm:ttUPIttUc²manragdUcsarayénterIdUPIt ferns, produced by germination of the spore. nigbNѽgÁCati EdlekIteLIgedaydMNuHéns,:. prothrombin : A constituent of blood plasma that is changed to RbÚRtMúb‘Ín ³ Fatubgáén)aøsµaQamEdlnwgbMElgeTACaRtMúb‘Ín edayRtMúbUKI- thrombin by thrombokinase in the presence of calcium ions; involved NasenAeBlmanvtþmanGIuyu:gkal;süÚm. varYmcMENkkñúgkMNkQam. in blood clotting. protist : A eukaryotic organism, in old systems of classification, RbÚTIsþ ³ Pavrs;GWkarIy:Ut ¬kñúgRbB½n§cMENkfñak;cas; ¦ eRcInEtCaÉk- usually unicellular, that is not a plant or an animal. Includes ekasika EdlminEmnCarukçCati rWstVeT. EdlrYmman sarayÉekasika unicellular algae, diatoms, düatUem RbUtUsUEG‘ nigpSit slime moulds . emIlTMBr½ 312 . protozoa and slime moulds. See p. 312. protocell : The first living cell. ekasikaedIm ³ekasikamanCIvitdMbUg. protoderm : The outermost tissue of an apical meristem; produces the RbUtUEDm ³ CalikaeRkAbg¥s;énemCalikacug. vabegáIteGBIEDm. epidermis. proton : Nuclear particle with a 1amu + 1 mass of 1 amu and an electric RbÚtug ³ PaKl¥iténéNVy:UEdlmanma:s nigbnÞúkGKIÁsnI . charge of + 1. protonema : A filamentous stage that becomes the gametophyte in RbÚtUenm:a ³ dMNak;kalCaPVILam:g;EdlnwgkøayeTACakaEm:tUPIt mosses. cMeBaHEsø. proto-oncogene : A cellular gene that normally functions to control RbUtUGugkUEsn ³ EsnekasikaEdlCaFmµtamanmuxgarRtYtBinitükar cell reproduction. Proto-oncogenes can be converted to oncogenes by bnþBUCekasika. RbUtUGugkUEsnGacRtYv)anbMElgeTACaEsnbgáCMgW changes in structure or expression. mharIkedaykarpøas;bþÚrTMrg; b¤karsMEdgecj. protoplasm : The living portion of a cell as distinguished from the RbÚtU)øas ³ EpñkmanCIvitrbs;ekasikaEdlxusBIPñaseRKagKµanCIvit. nonliving cell wall. RbÚtU)øasrYmmansIutU)øasnigéNVy:U. protoplast : A bacterial or plant cell with the cell wall removed. RbÚtU)aøs ³ ekasika)ak;etrI b¤ekasikarukçCatiEdlRtUv)anykPñaseRKag Sometimes called a spheroplast. ecj ehIyeBlxøHehAfaEsV‘r:U)aøs. protostomy : Condition in which the embryonic blastopore forms the RbÚtUsþÚm ³ sßanPaBEdl)aøsþÚB½rGMRb‘Íyu:g nwgkøayeTACamat;rbs; mouth of the adult animal. See also deuterostomy deuterostomy. stVeBjv½y. emIl . prototroph : A strain (usually microorganisms) that is capable of RbUtURtUb ³ BUC ¬CaTUeTAmIRkUsarBagÁkay ¦ EdlmansmtßPaBlUtlas; growth on a defined, minimal medium. Wild-type strains are elImCÄdæanGb,brimakMnt;c,as;las;. BUCéRBeRcInEtRtUv)ancat;TukfaCa usually regarded as prototrophs. BYkRbUtURtUb. protoxylem : The first xylem cells formed in the primary xylem. RbÚtUsuIELm ³ekasikasuIELmTI 1 EdlmanenAkñúgsuIELmdMbUg. protozoa : Heterotrophic, unicellular organisms. They can be RbÚtUsUEG‘ ³ Pavrs;ÉkekasikabrCIB. vaGacCabrCIb saRbUPIt holophytic, saprophytic or holozoic when obtaining nutrients. They can b¤k¾GULÚsUGIuc eBlEdlvaTTYl)ansarFatuciBa©wm. vaGaceFVIclna move by flagella, cilia or edaypøaEsl eramj½r rWedayeCIgbeBaäat nigbnþBUCedaykarEckekasika pseudopodia and reproduce by fission or conjugation. rWCMnab;bþÚr.

protraction : Movement away retraction from the center of the body. See clnaecj ³ clnaecjBIcMNuckNþalénxøÜn. emIl . also retraction. protrusible (adj) : Capable of being moved away (protruded) BnøÚtecj)an ³ EdlGacBnøÚtecjBIxøÜn)an. from the body. proventriculus : The first part of a bird’s stomach that secretes gastric fg;RkBH ³ 1- EpñkdMbUgrbs;RkBHbkSIEdlbeBa©jrsRkBH. juices; a sac anterior to the gizzard in earthworms. 2- fg;enAxagmuxRkBHCenøn. proximal tubule or proximal convoluted tubule: A thin tube bMBg;bt;EbnCit ³ bMBg;esþIgEdlP¢ab;eTAnwgkenSambUEmn connected to Bowman’s capsule in a nephron of the kidney, which is énenRhVúgtMrgenam Edlr:ab;rgkarRsUbeLIgvijnUvm:UelKulmantMéleRbI responsible for reabsorbing most of R)as;)an EdlRtUv)aneRcaHBIkøÚemrulcUleTAkñúgkenSambUEmn. the valuable molecules filtered from the glomerulus into Bowman’s capsule. pseud- , pseudo- : prefix that means either false or similar to. beBaäat Ekøg rWdUc ³ buBVbTEdlmann½yfaxus b¤RsedogKñaeTAnwg. pseudoalleles : Genes that behave as alleles to one another by GaELlEkøg ³ EsnEdldMeNIrkarCaGaELlbMeBjKñaeTAvijeTAmk complementation, but that can be separated from one another by b:uEnþGacRtUv)anpþac;ecjBIKñaedaykarbnSMeLIgvij. recombination. pseudocoel : An internal body cavity lying between the outer pSWdUEsl ³ RbehagxøÜnxagkñúg EdlsßitenAcenøaHépÞsac;dMuxageRkA body wall musculature and the gut; not lined with mesoderm and énxøÜn nigbMBg;rMlayGahar. RbehagenHminEmnekItBIemsUEDmeT generally formed by persistence of nigCaTUeTAkekItBIsMNl;Rbehag)aøsþÚLaénGMRb‘Íy:ug. the embryonic blastocoel. pseudodominance : The appearance of a recessive lubEkøg ³ karelceLIgnUvepNUTIbGn;edaysarEtkar)at;muytasüúg phenotype due to the deletion mutation of a dominant allele in a énGaELllubéneGetr:UsuIkUt. heterozygote. : A nonfunctional gene with a similar sequence to a pSWdUEsn ³ EsnKµanmuxgar EdlmantMnlMdab;RsedogKñaeTAnwg known structural gene present elsewhere in the genome. EsnTMrg;sÁal;mYymanenAkEnøgepSgeTotkñúgesNUm. pseudoplasmodium : A phase of slime mold cellular slime molds in which the )aøssµÚdüÚmEkøg ³ vKÁénekasikamYyrbs;pSit Edlkñúg myxamoebae do not fuse but join myxamoebae together into a sluglike body that enaHekasika minrlaycUlKñaeT b:uEnþpþúMKñaCaGgÁmYydMu moves as a unit. EdleFVIclnaCaÉktamYy. pseudopodium ( pl. pseudopodia) : Amorphous protrusions of eCIgbeBaäat ³ EpñklyecjKµanragBitR)akdénsIutU)aøs Edlman cytoplasm involved in the ; locomotion and feeding of muxgarbMlas;TI nigcab;GaharénGamIb nigRbUtUsUEG‘maneCIgbeBaäat amoebae and related protozoans; eCIgrbs; rotifer . foot of a rotifer. pseudoscience : The use of the appearance of science to mislead. viTüasaRsþEkøg ³ kareRbIsPaBxageRkAdUcviTüasaRsþeFIVeGaymnusS The assertions made are not valid or reliable. e.g. Astrology. yl;xus. GMNHGMNagEdlKµantMél rWminKYreGayTukcitþ)aneT. ]TahrN_ ³ eharasaRsþ . psychological dependence : A addiction strong emotional need for a drug. ejónpøÚvcitþ ³ tMrUvkarCacaM)ac;nUvfñaMejon. emIl . See addiction.

pterosaur : An extinct flying reptile that flourished during the etr:Us½r ³ lµÚnehIrEdlrlt;putBUC nigEdlrIkduHdalxøaMgenAs½k Mesozoic. emsUsUGuic. puberty : A time, usually in the early teenage years, when the sex PaBRKb;kar ³ ry³eBldMNak;dMbUgényuvv½y EdlGrm:UnePTCMrujeGay hormones cause the release of eggs from the ovary, sperm production mankarbeBa©jkaEm:tjIBIGUEv eGaymankarplitEs

pyloric caeca : 1. Pouches extending from the upper end of fñk;BIL ³ 1- fg;lyecjBIxagcugeBaHevonRtI. the intestine in fish. 2. A pouch that opens into the ventriculus of 2- fg;mat;cMhcUleTAkñúgRkBHstVl¥it. an insect. 3. One of the paired 3- fg;bMBg;KUkñúgédpáaysmuRTnImYy². tubes in each ray of a starfish. pyloric sphincter : A valve located at the end of the stomach sac;dMuTVareRkamRkBH ³ RbwscugRkBH manmuxgartMrUvlMhUrGahar that regulates the flow of food from the stomach to the duodenum. BIRkBHeTAkñúgKl;eBaHevon. pylorus : The opening between the stomach and duodenum which TVareRkamRkBH ³ RbehagebIkcenøaHRkBH nigKl;eBaHevon Edlman is guarded by a valve. RbwskarBarmYy. pyranose : Six-membered ring form of monosaccharides. The ring BIra:NUs ³ TMrg;vg;R)aMmYyRCúgénm:UNUsak;karIt. vg;enHdUcKñanwgsiuc resembles the cyclic ether pyran. eGETBIra:nEdr. pyrenoid : A starch-forming structure embedded in the BIerNUGIut ³ TMrg;begáItGamIdugenAkñúgkør:U)aøs. chloroplast. pyrimidine : A one-ringed nitrogen-containing base that is BIrImIDIn ³ )asGasUtrgVg;mYy EdlCaEpñkmYyénnuyekøGUTIt . RbePT part of a nucleotide; the most common pyrimidines are thymine, BIrImIDInEdlTUeTAbMputenaH KWTImIn suItUsIun nigG‘uyr:asuIl. emIlTMBr½ cytosine, and uracil. See p. 318. 318 . pyruvic acid : A three-carbon compound that is the end product GasIutBIruyvic ³ smasFatukabUnbI EdlCapliplcugeRkayénkar of glycolysis. bMEbkKøúykYs. Q quadrat : An area of ground m2 surface, usually 1m 2 , used as a kVaRdat ³ CaEpñkmYyénépÞdI CaTUeTAmanTMhM ! EdleRbIeFVICakta sample unit in ecology. KMrUenAkñúgeGkULÚsuI. quantitative inheritance : See polygenic inheritance polygenic inheritance. emIl . quantum numbers : Set of numbers used to designate an elec- cMnYnkg;Tum ³ elxsMrab;kMnt;RkumeGLicRtugcMbg sNæanGrb‘Ítal; tron’s major electron group, its orbital shape, and its orbital nigdMeNATisGrb‘Ítal;rbs;va. orientation. quantum speciation : Formation of a new species within one or two kMNRbePTkg;Tum ³ karbegáItRbePTfµIkñúgmYyCMnan; b¤BIrCMnan; generations by a combination of natural selection and genetic drift. edaybnSMénCMerIsedayFmµCati nigsMNat;esenTic. quaternary carbon : Carbon atom that is bonded to four other kabUnkVaETEn ³ GatUmkabUnEdlRtÚv)anP¢ab;eTAnwgkabUnbYnepSgeTot. carbons. quaternary protein structure : Interaction between two or more RbÚetGIunTMrg;TIbYn ³ GnþrGMeBIrvagRcvak;b:UlIbuibTItBIr b¤eRcInsßitkñúg polypeptide chains within a protein molecule. e.g. hemoglobin. m:UelKulRbUetGuInmYy. ]TahrN_ ³ eGm:UkøÚb‘Ín. queen bee : The only egg-laying female of a hive. esþcXµMú ³ XµúMjIEtmYyKt;EdlBgénXµMúmYysMbuk. quiescent center : The relatively inactive region in the apical tMbn;Gskmµ ³ tMbn;GskmµenAkñúgemCalikacugrws. meristem of a root

quill feathers : Feathers on the wings and tail that help to stabilize søabEkv ³ søabEdlsßitenAelIpÞaMgsøabnigknÞúyEdlCYyrkSalMnwg a bird in flight. bkSIenAeBlehIr. quinine : An antimalarial drug originally extracted from the bark KInIn ³ fñaMsMrab;Büa)alCMgW®Kuncaj; EdleKcMraj;ecjBIsMbkeQI of the South American cinchona cinchona tree. enAGaemricxagt,Úg. quinone : Common name for 2,5- –1,4- 2,5-cyclohexadiene-1,4-dione, the KINUn ³ eQµaHTUeTAsMrab; sIukøÚGiucsaDIEGn DIGUn EdlCa oxidation product of hydroquinone. plitplGuksIutkmµénGIuRdÚKINUn. R R factor (R plasmid, resistance R R factor) : Bacterial plasmids that ktþa ¬b¤)øasµIt ¦ ³ )øasµIt)ak;etrIEdlmanEsnFn;nwgGg;TIbüÚTic. carry antibiotic resistance genes. R R-determinant Most R plasmids have two com- )øasµIt PaKeRcInmansmasPaBBIrKW EdldwknaMEsn ponents: an R-determinant, which Fn;nwgGg;TIbüÚTic nigktþabBa¢ÚnFn; (RTF) . carries the antibiotic resistance genes, and the resistance transfer factor (RTF) . R group : A general term for the R side group of a molecule, such as a Rkum ³ BaküTUeTAsMrab;RkumcMehogrbs;m:UelKulmYy dUcCa methyl group, a hydroxyl group, or a monosaccharide. RkumemTIl RkumGIuRduksuIl b¤ m:UNUsakarIt. R point : The time (also known as R ³ ry³eBl ¬CaFmµtaCacMnuckMNt; ¦ kñugvKÁ G1énvdþekasika the restriction point) during the G 1 cMNuc stage of the cell cycle when the cell ADN decides to, either begin DNA ekasikasMercfaetIRtUvcab;epþImkarsMeyaK nigbnþvdþekasika synthesis and continue the cell b¤bBaÄb;vdþenH ehIysMrak. cycle, or to withdraw from the cycle and rest. race : A distinct population of a species; a subspecies. BUC b¤RbePTrg ³ b:UBuyLasüúgedayELkrbs;RbePTmYy. racemic mixture : Mixture that contains equal amounts of a pair of l,ayra:esmiuc ³ l,ayEdlmanbrimaNKUeGNg;tüÚEmesIµKña enantiomers and thus does not rotate plane-polarized light. nigminbEgVrbøg;énkaMrsµIb:UEl. rachilla : The cup shaped base that supports the flower or seed. r:asIuLa; ³ TMrg;dUcEBgEdlRTRTg;páab¤RKab;. Rad : See radiation absorbed Rad radiation absorbed dose dose. ³ emIl . radial cleavage : A form of early cell division in which all cleavage cMENkkaM ³ TMrg;éncMENkekasikadMbUg²Edlbøg;EckTaMgGs; planes are perpendicular, so daughter cells come to lie directly sßitenAEkgKña dUecñHekasikakUnsßitenACab;²KñaCabnÞat;. in line with each other. radial symmetry : A type of symmetry in which an organism sIuemRTIkaM ³ RbePTsIuemRTIEdlsarBagÁkayGacRtUv)anEckeTACaBIr can be divided into equal halves by passing a plane through the central cMehogesµIKñaedayGUsbøg;kat;G½kSkNþalsarBagÁkaytamTisNa axis of the animal in any direction. k¾eday.

radiation absorbed dose (Rad) : Unit roughly equivalent to the GRtaRsÚbrsµI³ xñatsmmUleTAnwgr:ugEsnEdlBN’naBIbrimaNfamBl roentgen, which describes the amount of energy deposited in kñugCalikapþl;edaykaMrsµIGiucb¤rsµIháama:. GRtaRsUbrsIkñúgxøÜnTaMgmUl tissue by X-rays or gamma 450 rad bNþaleGayb:UBuyLasüúgsøab;Gs; 50 PaKry. radiation. A whole-body dose of 450 rad is fatal to 50 percent of the population. radicle : The part of an embryonic plant that will become the root. rwsBnøk ³ Epñkrbs;GMRb‘Íy:ugrukçCati EdlnwgkøayeTACarws. radioactive : A term used to describe unstable atomic nuclei viTüúskmµ ³ BaküeRbIedIm,Ierobrab;BIéNVy:UGatUmminzitefr EdlEbk that break down, releasing particles and energy. edaybeBa©jpg; nigfamBl. radioactive decay : Process by which an unstable nucleus emits karbMEbkviTüúskmµ ³ lMnaMEdléNVy:UKµansßirPaBbeB©ajkaMrsµI Gal;hVa alpha or beta and gamma radiation. rWebtanigháama:. radioactive fallout : Radioactive particles carried by air currents. karFøak;viTüúskmµ ³ pg;viTüúskmµdwknaMedaycrnþxül;. radioactive isotope : Atoms of an element with an unstable nucleus GuIsUtUbviTüúskmµ ³ GatUménFatumanéNVy:Uminzitefr that emits ionizing radiation. EdlbeBa©jrsµIGuIy:ugkmµ. radiocarbon dating : Determination of the age of an karkMNt;kabUnviTüúskmµ ³ karkMnt;Gayurbs;vtßúmYyedaykarvas; object by measuring the amount of radioactive carbon present relative brimaNkabUnviTüúskmµEdleFobeTAnwgbrimaNKMrUrs;Rbhak;RbEhlKña. to the amount in a similar living karkMnt;GayuéNVy:Uk¾GacBwgEp¥keTAelIGIusUtUbepSgeTotpgEdr dUcCa sample. Nuclear dating can also be based on other isotopes, such as tUrüÚ:m b¤G‘uyra:jÚ:m nigsMN. thorium or uranium and lead. radius : One of the two parallel bones in the lower part of the q¥wgtUckMPYnéd ³ q¥wgmYykñúgcMeNamq¥wgRsbKñaBIrénEpñkxageRkamén forelimb of tetrapods. See pentadactyl limb, pentadactyl limb, and p. 321. q¥wgGvyv³muxrbs;stVeCIgbYn. sUmemIl nigemIlTMBr½ 321 . radula : A feeding device in mollusks having tooth-like r:adULa ³ Rbdab;sIuGaharrbs;sib,IstV EdlmanEpñklyecjdUcCa projections for scraping. eFµjsMrab;Rtdus. rancid : Term used to indicate that a fat or oil is foul-smelling and xar ³ BaküeRbIsMrab;bBa¢ak;BIxøaj;b¤eRbgEdlmankiønGaRkk; nig bad-tasting due to the presence of volatile acids and aldehydes. manrsCatiminq¶aj; EdlbNþalmkBIvtþmanrbs;GasIut nigGal;edGIut ehIr. random mating : Selection of mates by chance that is not karbgáat;edayécdnü ³ kareRCIserIsKUbgáat;edayPaBEcdnüEdl influenced by genotype. e.g. in humans, the selection of mates is minTTYl\T§iBledayesNUTIbeT. ]TahrN_ ³ cMeBaHmnusS kareRCIs usually not influenced by blood erIsKURKgCaFmµtaminTTYl\T§iBledayRkumQameT. groups. range : The geographical distribution of a species. cenøaHr)ay ³ r)ayPUmisaRsþrbs;RbePTmYy. ray initials : Cells in the vascular cambium that produce the ray cells ekasikakaMdMbUg ³ ekasikaenAkñúgkMbüÚmsrésnaM EdlplitRsTab; of secondary xylem and secondary phloem. ekasikakaMsIuELmTIBIr nigpøÚEGmTIBIr.

RDP (ribulose diphosphate) : A RDP : five-carbon sugar found in the sárkabUnR)aM manenAkñúgkør:U)aøsEdlmanmuxgarP¢ab;kabUn . chloroplasts that functions in carbon fixation. reactant : A substance entering into a chemical reaction. Rbtikr ³ sarFatuEdlcUlrYmkñúgRbtikmµKImI. reaction rate (velocity) : Rate at which a reaction occurs, usually el,ÓnRbtikmµ ³ el,ÓnEdlRbtikmµRBwtþeTACaFmµtabBa¢ak;kñúgn½yEdl expressed in terms of substrate consumed per unit time or product s‘ubRsaþRtÚv)aneRbIkñúgmYyÉktaeBlevla b¤plitplkekItkñúgmYy formed per unit time. ÉktaeBlevla. reaction wood : Wood produced in response to a stem that has lost sac;eQIRbtikmµ ³ sac;eQIEdlekIteLIgkñúgcMelIytbeTAnwgedIm its vertical position; reaction wood straightens the stem. b¤EmkEdl)at;bg;CMhrrbs;va ehIyRbtikmµsac;eQICYyBRgwgedImb¤Emk enaHeLIgviij. reading frame : Starting point where linear sequence of codons RkmGan ³ cMNuccab;epþImEdltMNlMdab;ExSkUdug (groups of three nucleotides) in a nucleic acid is read. ¬RkuménnuyekøGUTIt 3 ¦kñúgGasuItnuyekøGuicRtUv)anGan. reasoning : Rational thinking; the ; ; ability to solve an unfamiliar karBicarNa karedaHRsay ³ karKitRbkbedayvicarNBaØaN problem without any trial-and-error process. lT§PaBkñugkaredaHRsaybBaðaEdlminEdlCYbRbTH edayKµandMenIr sakl,gnigxuseLIy. reassociation kinetics : the technique that measures the rate of GRtaP¢ab; ³ bec©keTsvas;GRtaénkarP¢ab;Rcvak; EdlbMeBjKñarbs; connection of complimentary ADN strands of DNA from a single ecjBIRbPBRcvak;mçag. source . receptacle : The enlarged tip of a stem that supports the flower. TMrpáa ³ EpñkrIkFMrbs;Emkb¤TgEdlRTRTg;páa. receptor : Tissue or cell that can respond to a stimulus; a sense FµÜl ³ Calika rWekasikaEdlGaceqøIytbeTAnwgrMejac ]TahrN_ ³ organ. eg, see stretch receptor. srIragÁviBaØaN. emIl stretch receptor . recessive : A term used to describe a gene or trait that is hidden by a Gn; ³ BaküeRbIsMrab;BN’naEsnmYy rWlkçN³mYyEdlRtUv)an dominant gene. )aMgbitedayEsnlub. recessive allele : An allele that is masked by the effects of other GaELlGn; ³ GaELlEdlmin)ansMEdgecj eday\T§iBlrbs; alleles for the trait. GaELlepSgeTotsMrab;lkçN³enaH. reciprocal cross : A paired cross in which the genotype of the karbgát;bRBa©as ³ karbgáat;KUEdlepNUTIbénePTjIenAkñúgkarbgáat; female in the first cross is present as the genotype of the male in the elIkTImYymanvtþmanCaepNUTIbénePTeQµalenAkúñgkarbgáat;elIkTIBIr second cross, and vice versa. nigRtlb;bRBa©as;mkvij. reciprocal translocation : A chromosome mutation in which bMlas;bþÚrKñaeTAvijeTAmk ³ muytasüúgRkUm:UsUmEdlRkUm:UsUmmin non-homologous chromosomes exchange parts. GUm:ULÚkpøas;bþÚrKñanUvEpñkTaMgLayrbs;va. recombinant DNA : DNA that ADN ADN has been constructed by inserting bnSMeLIgvij ³ EdlRtUv)anbegáIteLIgedaykarbBa©Úl new pieces of DNA into the DNA ADN ADN of another organism, such as a Ggát; fµIeTAkñúg rbs;Pavrs;epSgeTot dUcCacMeBaH)ak;etrI bacterium. CaedIm.

recombinant DNA technology : ADN genetic engineering See genetic engineering. bec©kviTüabnSM eLIgvij ³ emIl . recombinant gamete : A gamete containing a new combination of kaEm:tbnSMfµI ³ kaEm:tmanbnSMfµIénEsnEdl)anpliteday genes produced by crossing over during meiosis. )atuPUtRkUsuIjGUevIkñúgeBlemy:Us. recombination : The process that leads to the formation of new gene karbnSMfµI ³ dMeNIrEdlnaMeTAdl;karbegáItbnSMEsnfµIenAelIRkUm:UsUm. combinations on chromosomes. It can occur by independent vaGacekIteLIgedaykarpþac;ecjedayÉkraCüénEsnenAelIRkUm:UsUmxus assortment of genes on different Kña b¤edayRkUsuIjGUevIénEsnenAelIRkUm:UsUmdUcKñakñúgeBlemy:Us. chromosomes or by crossing over of genes on the same chromosome during meiosis. recombination nodule : A cluster of enzymes in a synaptonemal kMBkbnSMfµI ³ RkumGg;suImenAkñúgkMupøicsIuNab;EdleKeCOfavaeFVI complex, which are believed to act in concert to bring matching skmµPaBrYmedIm,IpÁÚpÁgbMENkRkUm:UsUmGUm:ULÚkCamYyKña. segments of homologous chromosomes together. Recommended Dietary Allowances (RDA) : U.S. dietary dMbUnµanBItMrUvkarGahar ³ karENnaMBIrbbGaharenAshrdæGaemrik guidelines for a, healthy person that focus on the amounts of foods sMrab;GñkmansuxPaBl¥ EdlykcitþTukdak;elItMrUvkarbrimaNGahar BI desired from six classes of GaharTaMg6Rkum. nutrients. recon : A term to describe the smallest genetic units between rIxn ³ BaküsMrab;BiBN’naBIÉktaesenTictUc²CageKEdlkarbnSMfµI which recombination can occur. GacekIteLIgenAcenøaHÉktaTaMgenaH. rectum : The end of the large intestine. cugeBaHevon ³ EpñkxagcugéneBaHevonFM. red blood cells : See erythrocyte. eKalikaQamRkhm ³ emIl erythrocyte . red-green color blindness : The inability to distinguish red from CMgWggwtBN’¬dal;tUnIs¦ ³ KµanlT§PaBEbgEckBN’RkhmBIBN’ green due to lack of colour absorbing pigments in the cone Ebtg edaysarkgV³énBN’RsUbCatiBN’enAkñúgekasikaekanrbs;erTIn. cells of the retina. Caused by a vabNþalmkBIEsnGn;sißtenAelIRkUm:UsUm X. recessive gene defect on the X chromosome. redirected aggression : A behavior in which the aggression karKMrambEgVrTis ³ Gakb,kiriyaEdlkarKMramrbs;stV KWedIrecj of an animal is directed away from an opponent and to some other b¤gakecjBIKURbqaMgrbs;va niggakecjBIstVmYyb¤BIvtßúmYycMnYnepSg animal or object. eTot. redox reaction : Reaction that involves both oxidation and Rbtikmµerduk ³ RbtikmµEdlTak;TgeTAnwg GuksIutkmµ nigerdukkmµ. reduction. reducing atmosphere : An atmosphere that does not contain briyakasbRgÜm ³ briyakasEdlKµanm:UelKulGuksIuEsn. molecular oxygen (0 2). reducing sugars : Sugars that have a free carbonyl group that can be sárerdukr ³ sárEdlmanRkúmkabUnIlesrIehIyGacTTYlrgGuksIutkmµ. oxidized. They are thus reducing agents. eg. glucose, fructose. dUecñHvaCaPñak;garerdukr. ]/ KøúykUs/ RhVúctUs.

reduction : Gain of electrons in a chemical reaction. e.g. When erdukmµ ³ karcMeNjeGLicRtúgkñúgRbtikmµKImI. ]³enAeBldutkMedA heated with carbon (coke), the iron 3+ Fe (Fe 203) Fe 3+ in the iron ore hematite CamYykabUn Edk kñúgEr:EdkeGma:TIt cMeNjeGLicRtúg o (Fe 203) gains electrons and is nigRtÚv)anrgerdukmµCaEdkelah³ Fe . reduced to metallic iron, Fe o. reduction division : A type of cell division in which daughter cMENkbnßy ³ RbePTcMENkekasika EdlekasikakUnTTYl)an cells get only half the chromosomes from the parent cell. RkUm:UsUmEtBak;kNþalénRkUm:UsUmrbs;ekasikaem. sTisn½ynwgBakü A synonym for meiosis I. emy:Us I. reductionism : The approach of studying simpler components in TsSn³samBaØ ³ karsikSaBIsmasFatugay²CagedIm,IeGayyl; order to understand the functions of complex systems. BImuxgarénRbB½n§d¾saMjaMrbs;va. redundant genes : Gene sequences present in more than one EsnmancMnYneRcIn ³ tMnlMdab;EsnEdlmaneRcInCagmYy copy per haploid genome (e.g., ribosomal genes). kñúgesNUmGabøÚGuItmYy ¬ ]TahrN_ ³ EsnénrIbUsUm ¦. reflex (reflex arc) : An automatic response to a stimulus as a result of erpøic ¬FñÚerpøic¦ ³ tMNbsV½yRbvtþieTAnwgrMejacEdlCalT§pl nerve connections between receptor and effector organs via énCMnab;ekasikaRbsaTrvagsrIragÁFµÜl nigsrIragÁclkr tamry³ NWrU:n interneurons so that the brain is not cenøaH dUecñHxYrk,almin)ancUlrYmeT. involved. refugium : Isolated area of habitat fragmented from a formerly more CMrkePosxøÜn ³ tMbn;rs;enAdac;BIeK EdlEbgEckBItMbn;CIv³BImund¾ extensive biome. TUlMTUlay. regulator proteins : Proteins that influence the activities that occur RbÚetGuIntMrUv ³ RbUetGIunEdlman\T§iBleTAelIskmµPaBEdlekItman in an organism-for example, enzymes and some hormones. enAkñúgsarBagÁkay. ]³ Gg;sIumnigGrm:UnmYycMnYn. regulatory site : A DNA sequence ADN that is involved in the control of tMbn;tMrUv ³ tMNlMdab; EdlcUlrYmkñúgkarRtYtBinitüénkarsMEdg expression of other genes, usually involving an interaction with ecjrbs;EsndéTeTot EdlCaFmµtamanGnþrGMeBICamYynwgm:UelKulmYy another molecule. (see operon). eTot ¬emIlGUeb:r:ug³ operon ¦. reinforcement : A reward used in learning situations. karpþl;rgVan; ³ rgVan;EdleRbIenAkñúgsßanPaBsikSa. relative atomic weight : Average mass of a sample of atoms of an ma:sGatUmeFob ³ ma:smFüménKMrUGatUm énFatumYyeRbóbeFobeTAnwg element, as compared with an accepted standard. The original sþg;damYyEdleKTTYlsÁal;. sþg;daedImCaGatUmRsalbMput KWGIuRdÚEsn standard was the lightest atom, Edlma:sGatUmRtÚv)ansnµtfaesIµnwgmYy. karsMGagenHRtÚv)anpøas;bþÚr hydrogen, assigned an arbitrary atomic mass of 1.000. The fµI²enH KWykGatUmkabUnCatYy:agrYmbMput edaymanma:sRtwmRtÚvKW12amu reference was changed recently to the most common type of carbon ¬Baküma:sGatUmRtÚv)aneRbIedayGacbþÚrKña)annigman PaBRtwmRtÚvCag¦. atom, which was assigned a mass of exactly 12 amu. (The term atomic mass is used interchangeably and is actually more accurate.)

release factors : A group of cytoplasmic proteins that bind to a ktþabBa©b; ³ RkumRbUetGuInsuItU)aøs EdlrMuP¢ab;eTAnwgkUdugsþúbmYyelI stop codon on a molecule of ARN m mRNA and interrupt translation by m:UelKul nigbg¥ak;karbkERbRkm edayeFVIGuIRdUlIssm<½n§rvag hydrolyzing the bond between the GasuItGamIenenAkñúgb:UlIbuibTIt nig ARN dwknaMrbs;va. final amino acid in a polypeptide and its transfer RNA. releasing factor : Any of a group of hormones produced by the ktþabeBa©j ³ RkumGrm:UnbeBa©jedayGIub:UtaLamus EdlePaJcGIub:UPIs hypothalamus that stimulates the inhibiting factor pituitary to secrete specific eGaybeBa©jGrm:UnyfaRbePT. emIl . hormones. See inhibiting factor. reliable (adj) : A term used to describe results that remain EdlykCakar)an/EdlKYreGayeCO)an ³ BaküEdleRbIedIm,IBN’na consistent over successive trials. lT§plEdlminmankarERbRbYlenAkñúgkarsakl,gCabnþbnÞab;. Rem : See Roentgen equivalent Roentgen equivalent man man. erm ³ emIl . REM(rapid eye movement) sleep: Period during sleep when dMeNkEPñkmanclna ³ ry³eBledkmanyl;sbþi_. dreaming occurs. renal arteries : Arteries bringing blood to the kidneys. GakETtMrgenam ³ GakETEdlnaMQameTAtMrgenam. renal cortex : The outer layer of the kidney. EpñksMbktMrgenam ³ RsTab;xageRkArbs;tMrgenam. renal medulla : The inner portion of the kidney. EpñkkNþaltMrgenam ³ Epñkxagkñúgrbs;tMrgenam. renal pelvis : A cavity in the kidney in which urine collects. kBa©úMtMrgenam ³ RbehagsßitkñúgtMrgenamEdlCakEnøgRbmUlpþúMTwk enam. renal threshold : Maximum concentration of a substance that kMritRBMx½NÐtMrgenam ³ kMhab;GtibrmaénsarFatuEdlRtÚv)anRsUbyk can be effectively reabsorbed by the kidneys. If the concentration edaytMrgenam. ebIsinCakMhab;elIsBIkMritenH sarFatuenaHnwgbeBa©j exceeds this threshold, the eTAkñúgTwkenam. substance will appear in the urine. renal vein : Vein taking blood from the kidneys. Ev:ntMrgenam ³ Ev:nEdlnaMQamecjBItMrgenam. renaturation : The process by which a denatured protein or karvilmksPaBedImvij ³ dMeNIrEdlRbUetGuInb¤GasuItnuyekøGuic nucleic acid returns to its normal three-dimensional structure. NaEdl)at;bg;BIlkçN³FmµCatiehIyRtLb;eTATMrg;vimaRtbICaFmµta rbs;vavij rWRtlb;eTATMrg;edImrbs;vavij . renewable resource : A resource that is unlimited in supply. FnFanminecHrIgs¶Üt ³ FnFanEdlpþl;eGayedayKñankMrit. rennin (chymase) : An enzyme secreted by the gastric glands of ernnIn ¬sIum:as ¦ ³ Gg;suImbeBa©jedayRkeBjrs;RkBHénPñas the stomach wall, that coagulates milk protein to form an insoluble RkBH EdleFVIeGayRbUetGIunTwkedaHkkedIm,IbegáItCasarFaturwgminrlay solid which is more easily digested. EdlgayrMlayCag. vamansar³sMxan;cMeBaHfnikstVenAekµg. This is important for young mammals. repetitive DNA : Sequences of ADN ADN DNA that occur in many copies in dEdl² ³ tMNlMdab; EdlmancMnYny:ageRcInenAkñúg a genome; some sequences of ADN repetitive DNA can occur in a esNUmmYy. tMNlMdab; dEdl²xøHGacmanrhUtdl;mYylankñúg million copies per nucleus éNVy:UmYy.

replicating form (RF) : Double-stranded nucleic acid mol- TMrg;sV½ydMeLIgeTV ³ m:UelKulGasuItnuyekøGuicRcvak;eTV EdledIrtYCa ecules present as an intermediate during the reproduction of certain FatukNþalkñúgkMLúgeBlbnþBUCrbs;vIrusmYycMnYn. viruses. replication : A process in which a DNA strand of DNA is copied exactly. sV½ydMeLIgeTV ³ dMeNIrEdlRcvak;mçagrbs; RtUv)ancMlgdUcKña See p. 318. ebHbit. emIlTMBr½ 318 . replication bubble : A region of ADN DNA that has been separated into ek¥gsV½ydMeLIgeTV ³ tMbn; EdlRtUv)anpþac;BIKñaeTACaRcvak; single strands between opposing replication forks. eTal rvagCMBamsV½ytMelIgeTVQm. replication fork : The region ADN where a DNA double strand is split CMBamsV½ydMeLIgeTV ³ tMbn;EdlCakEnøgRcvak;eTV EjkecjBIKña into separate strands, creating a fork-like appearance; once EdlbegáIt)anCasNæandUcsm b¤CMBam. enAeBlsV½ydMeLIgeTVcab;epþIm replication begins at a replication enARtg;RbPBsV½ydMeLIgeTV CMBamsV½ytMelIgeTVBIrRbRBwtþeTAtambeNþay origin, two replication forks proceed along the double helix in Rcvak;eTVrages<órkñúgTisedApÞúyKña. opposite directions from one another. replication origin : The point of ADN initiation of DNA synthesis along RbPBs½VydMeLIgeTV ³ cMnuccab;epþImkarsMeyaK tambeNþay the double helix; two replication forks form at the replication origin Rcvak;eTVrages<ór. CMBamtMeLIgeTVBIrekIteLIgenARtg;RbPBsV½ytMelIgeTV and move in opposite directions ehIyeFVIclnatamTispÞúyKñakñúgkMLúgeBlkarsMeyaK ADN . from one another during DNA synthesis. replicon : A block of DNA ADN between two adjacent replication tMbn;cenøaHRbPBsV½ydMeLIgeTV ³ tMbn; enAcenøaHRbPBsV½y- origins that is necessary for replication. dMeLIgeTVCab;KñaBIrEdlcaM)ac;sMrab;karsV½ydMeLIgeTV. replisome : The term used to describe the complex of proteins, erPøIsUm ³ BaküeRbIedIm,IBiBN’naBIkMpøicRbUetGuIn rYmman including DNA polymerase l, that ADN I assembles at the bacterial b:UlIEmra:s EdlpþúMKñaenARtg;CMBamsV½ytMelIgeTV)ak;etrI replication fork to synthesize edIm,IsMeyaK ADN . DNA. repression : Regulation of gene expression involving the turning karTb; ³ tMrUvkarsMEdgénEsnEdlrYmcMENkkñúgkarbBaÄb;Esn off of genes by the presence of a compound. edayvtþmanénsmasFatumYy. repressor : A protein that binds to a regulatory sequence next to a GñkraraMg ³ RbUetGuInEdlP¢ab;eTAnwgtMnlMdab;tMrUvenACab;nwgEsnmYy gene and blocks transcription of the gene. nigraraMgkarcMlgRkménEsnenaH. reproduction : A process by which organisms produce offspring karbnþBUC ³ dMenIrEdlPavrs;begáItkUn EdlRsedogKñaeTAnwgem)a. that are similar to themselves. See sexual reproduction,asexual reproduction sexual reproduction, asexual emIl . reproduction. reproductive barriers : Various mechanisms that prevent r)aMgbnþBUC ³ clnkarnanaEdlraraMgmineGaymankarbnþBUCrvag reproduction between individuals. usually from different species. Éktþ³TaMgLayEdlPaKeRcInmkBIRbePTepSgKña. reproductive capacity : The theoretical maximum rate of smtßPaBbnþBUC ³ GRtabnþBUCx

reproductive isolation : A barrier to interbreeding caused by varied r)aMgbnþBUC ³ r)aMgbgáat;BUCkñúgGuIRb‘ÍtEdlbNþalmkBIeBlevlabnþBUC breeding times or geographical factors. xusKñab¤mkBIktþaPUmisaRsþ. research method : A step-by-step procedure for investigating viFIRsavRCav ³ viFIGegátbBaðamYydMNak;kalmþg² EdlrYmman problems that includes analysis and experimentation. TaMgkareFVIviPaK TaMgkarBiesaFn_. reservoir : A depression at the anterior end of a euglena where the fg;mat; ³ kMhUgxagmuxrbs;GWeKøNa EdlCakEnøgduHpøaEsl. flagella attach. residue : 1. Monomer within an oligomer or polymer; the residues 1- eRKag ³ m:UNUEmenAkñúgGUlIhÁÚEm b¤b:UlIEm. eRKagrbs;GUlIhÁÚsa- of an oligosaccharide are occupied by monosaccharides. 2. A karItRtÚv)anbgáeLIgedaym:UNUsakarItCaeRcIn. substance that remains after some 2- kaksMNl; ³ sarFatuEdlenAsl;bnÞab;BIdMeNIrkarmYy cMnYn. process. eg. the solid remaining on filter paper after filtration. ]TahrN_ ³ FaturwgenAsl;Cab;nwgtMrg bnÞab;BIkare®caH. resin : A thick, translucent, combustible, organic fluid usually C½reQI ³ GgÁFaturavsrIragÁxab;føa nigGaceqH)an EdlCaTUeTARtUv)an secreted into resin ducts in pine trees and many other seed plants. beBa©jeTAkñúgbMBg;naMC½renAkñúgedImRsl; nigedImeQImanRKab;CaeRcIn epSgeTot. resin duct : An elongate intercellular space lined with bMBg;naMC½r ³ lMhGnþrekasikaEvg² EdltMerobCaCYrCamYynwgekasika resin-secreting cells and containing resin. beBa©jC½rnigpÞúkC½reQI. resistance factor : See R factor. emIl R factor . resistance transfer factor (RTF) : R A set of genes that gives the ability ktþabBa¢ÚnFn; ³ RkumEsnEdlpþl;smtßPaBedIm,IbBa¢Únktþa to transfer R factors from cell-to-cell by conjugation. ecjBIekasikamYyeTAekasikamYytamCMnab;bþÚr. resolution : See resolving power. kMlaMgBRgIk ³ emIl resolving power . resolving power : The ability of an instrument to separate and kMlaMgEjk ³ lT§PaBrbs;]bkrN_mYykñúgkarEjkvtßúBIreGaydac;BIKña. distinguish two objects. resonance energy : Energy due to delocalization of electrons. famBlersUNg; ³ famBlEdlnaMeGaymankarBRgayeGLicRtúg. respiration : 1. Process of converting food energy into a form degðIm ³³³ 1- dMenIrbMElgfamBlGahareGayeTACaTMrg;famBlEdl of energy usable by cells. Respiration using oxygen is the ekasikaGaceRbIR)as;)an. kardkdegðImedayeRbIGuksIuEsnKWCaRbPB principal source of energy in the famBld¾sMxan;kñúgsarBagÁkay. emIl anaerobic respiration, aerobic body. See anaerobic respiration, aerobic respiration. 2. The respiration . exchange of oxygen and carbon dioxide between cells and their 2- bNþÚrGuksIuEsnnig]sµ½nkabUnic rvagekasika nigbrisßanrbs;va. environment. See aerial aerial respiration, aquatic respiration respiration, aquatic respiration. emIl . response : The reaction of an organism to a stimulus. tMNb ³ Rbtikmµrbs;Pavrs;eTAnwgrMejac.

responsive processes : Those abilities to react to external and dMeNIreqøIytb ³ lT§PaBeqøIytbeTAnwgkarERbRbYlénbrisßanxagkñúg internal changes in the environment, e.g. immune response nigxageRkA. ]³ tMNbPaBsMuaeTAnwgPñak;garbgáCMgW-bnSaúMrbs;Éktþ³ to pathogens, individual nigvivtþn_. adaptation, and evolution. restriction endonuclease : Nuclease that recognizes specific Gg;dUnuyekøGaskMrit ³ Gg;suImnuyekøGasEdlsÁal;tMnlMdab;nuy- nucleotide sequences in a DNA ADN ADN molecule, and cuts the DNA at that ekøGUTItyfaRbePTkñúgm:UelKul nigkat; enARtg;kEnøgenaH. site. Enzymes that cut both strands Gg;suImEdlkat;Rcvak;TaMgBIrrbs;ADN RtUv)aneRbIkñugkarbegáItmU:elKul of the DNA are used in the construction of recombinant DNA ADN bnSMfµI. molecules. restriction enzyme : A group of ADN enzymes capable of separating Gg;sIumkMrit ³ RkumGg;sIum EdlGacbMEbk enARtg;cMNucyfa- DNA at specific points along the chain. RbePTtambeNþayRcvak;. restrictive condition ( also called non-permissive condition non-permissive condition) : l½kçx½NÐkMrit ¬b¤ ¦³ l½kçx½NÐbrisßanEdl Environmental conditions under which a conditional mutation (such l½kçx½NÐmuytasüúg ¬dUcCamuytg;EdlrYsnwgsuItuNðPaB ¦ sMEdgecj as a temperature sensitive mutant) epNUTIbmuytg;. expresses the mutant phenotype. restrictive transduction : See specialized transduction specialized transduction. dMNwknaMEsnkMrit ³ emIl . rete mirabile : “Marvelous net,” a complex mass of intertwined bNþajsrésbþÚr ³ {sMnaj;cMElk} bNþajsaMjauMénsrésbþÚrRbTak; capillaries specialized for exchange / of heat and/or dissolved substances Kña Edlmanmuxgarkñúgkarpøas;bþÚrkMedAnig rWrMlaysarFaturlayrvag between countercurrent flowing crnþQamhUreTAmk. blood. retina : A thin lining inside the eyeball containing light-sensitive erTIn ³ PñasesþIgsßitenAkñúgRKab;EPñk EdlmanekasikaFµÜlrYsnwgBnøW receptor cells called cones and rods that are connected to the optic ehAfaekasikaekannigekasikadMbgEdlRtUv)anP¢ab;eTAnwgsrésRbsaT nerve by bipolar cells. GubTicedayekasikaeTVb:Ul. retraction : Movement toward the protraction center of the body. See clnacUl ³ clnaeTArkcMNuckNþalénxøÜn. emIl . protraction. retrovirus : Viruses with RNA as ARN reverse genetic material that use the RbtivIrus ³ vIrusman CasMPar³esenTic EdleRbIGg;sIum enzyme reverse transcriptase for transcriptase ADN replication into double stranded sMrab;karsV½ytMelIgeTVeGayeTACa Rcv:ak;eTV. DNA. They get their name because vamaneQµaHrbs;vadUcenHedaysarBt’manesenTiceFVIdMeNIrecjBI the genetic information goes from RNA to DNA. e.g. HIV. ARN eTA ADN . ]TahrN_ ³ vIrus HIV . reverse transcriptase : A type of enzyme from viruses that catalyzes Rtg;RsÁIbtasRcas ³ Gg;suImmYyRbePTrbs;vIrusEdlkatalIs the synthesis of DNA from an ADN ARN RNA template; in genetics, reverse sMeyaK BIBum

reversion : A mutation that restores the wild-type phenotype. muytasüúgbRBa©s ³ muytasüúgEdleFVIeGayepNUTIbRtlb;eTArk PaBedImvij ¬Rtlb;eTArkepNUTIbéRBvij ¦. rhesus blood group : Human blood type determined by the RkumQamers‘us ³ RbePTQammnusSEdlkMNt;edayvtþman presence or absence of rhesus factor. b¤Gvtþmanénktþaers‘us. rhesus factor (Rh factor) : A type Rh : of antigen on red blood cells. ktþaers‘us b¤ktþa RbePTGg;TIEsnéneKasikaQamRkhm. People with Rh factor are called Rh Rh Rh Rh positive and people without are mnusSEdlmanktþa ehAfa viC¢man nigmnusSEdlKµanktþa ehAfa called Rh negative. Rh GviC¢man. rhizoid : Root-like structures in fungi and bryophytes. rIsUGIut ³ TMrg;rwscMeBaHpSit nigRb‘Íy:UPIt. rhizome : A horizontal underground stem that has leaves ekþóg ³ edImEdlduHkñúgdI EdlmansøwknigRtYyBnøk. vamantYnaTI and buds. It functions as a food storage organ and for vegetative CasrIragÁpÞúkGahar nigsMrab;karbnþBUCeday\tePTénrukçCati. reproduction. rhodopsin : A light-sensitive pigment found in the rods of the r:UdubsIun ³ CatiBN’rYsnwgBnøWkñúgekasikadMbgrbs;erTIn. retina. rib cage : A structure formed from the ribs that protects many internal RbGb;RTÚg ³ TMrg;bgáeLIgedayq¥wgCMnI EdlkarBarsrIragÁxagkñúgRTUg organs of the thorax. Movements 321 of the rib cage cause breathing. CaeRcIn. clnaénRbGb;RTUgeFVIeGaymanclnadegðIm. emIlTMBr½ . See p. 321. ribonucleic acid (RNA) : A polymer of nucleotides formed on GasIutrIbUnuyekøGic ³ bUlIEménnuyekøGUlTIt EdlRtUv)anbegáIteLIg the template surface of DNA by ADN transcription which is a vital part of enAelIRcvak;Bum< edaykarcMlgRkm EdlCaEpñkd¾sMxan;sMrab;kar protein synthesis. Three forms that sMeyaKRbUetGIun. manTMrg;bIEdlRtUv)aneKsÁal;KW ARNm, ARNr, have been identified are mRNA, rRNA, and tRNA. ARNt . ribose : A 5-carbon sugar ARN molecule that is a component of rIbUs ³ m:UelKulsárkabUnR)aMEdlCaFatubgárbs; . RNA. ribosomal RNA (rRNA) : ARNr Ribonucleic acid molecules found GasIutrIbUnuyekøGiucrIbUsUm ¬ ¦ ³ m:UelKulGasIutrIbUnuyekøGiucEdl in ribosomes. manenAkñúgrIbUsUm. ribosome : A tiny, particle scattered throughout the cytoplasm rIbUsUm ³ FatuekasikatUc² sßitenAray)a:ykñúgsIutU)aøs. vaCaGñkbkERb It is the site of translation of ARNm mRNA to form proteins. Each Rkm edIm,IbegáItCaRbUetGIun. rIbUsUmnimYy²bgáeLIgedayRbUetGuIn ribosome is composed of protein nig ARN ehIymanÉktaBIr EdlmanTMhMxusKña. and RNA and consists of 2 different sized units. ribozyme : A sequence of RNA ARN that has enzymatic properties; first rIbUsIum ³ tMNlMdab; EdlmanlkçN³CaGg;suIm dMbUgRtUv)aneK named from a self-splicing intron. dak;eQµaHykecjBIGaMgRtugtedayxøÜnÉg. rickets : A deficiency disease in young children caused by lack of Rkis ³ CMgWkgV³CIvCati EdlekItmancMeBaHekµg²bNþalmkBIkgVH vitamin D, calcium and D phosphorus. vItamIn kal;süÚm nigpUsVr.

ring-porous wood : Wood having larger vessels in wood produced sac;eQIrn§vg; ³ sac;eQIEdlmansrésFM²kúñgsac;eQI EdlekIt early in the growing season than in wood produced late in the growing eLIgeRcInenAedImrdUvlUtlas;Cagsac;eQIEdlekIteLIgkñúgcugrdUv season, thereby producing a ring lUtlas; dUecñHkarplitvg;sac;eQIemIleXIjelIxñat;TTwgrbs;va. when viewed in a cross section of wood. R-loop : A sequence of DNA ADN within a gene that is displaced into EG-lUb ³ lMdab; kñúgEsnmYy EdlRtUv)anpøas;eTAkarly a loop-like projection when the ARNm gene is annealed to its ecjdUcrgVg; enAeBlEdlEsnenaHRtUv)anP¢ab;eTAnwg bMeBj complementary mRNA; the R-loop rbs;va. R-loop enHminP¢ab;CamYynig ARNm eT edaysarvaCa does not anneal with the mRNA because it is an intron whose GaMgRtugEdllMdab;bMeBjrbs;vaRtUv)ankat;ecjBIm:UelKul ARNm . complementary sequence has been spliced out of the mRNA molecule. RNA : See ribonucleic acid. RNA ³ emIl ribonucleic acid . RNA polymerase : An enzyme ARN ADN that attaches to the DNA at the bU:lIemra:s ³ Gg;sIumEdlP¢ab;eTAnwg Rtg;tMbn;RbUm:UT½rénEsn promoter region of a gene when the ARN genetic information is transcribed enAeBlEdlBt’manesenTicRtUv)ancMlgRkmeGayeTACa . into RNA. RNA processing (RNA splicing) : ARN ARN ARN The trimming of larger primary dMeNIrkar ¬kart ¦ ³ karkat;tMrwm cMlgRkmdMbUg RNA transcripts in the nucleus into smaller, coding sequences that are EdlmanRbEvgEvgenAkñúgéNVy:U eGayeTACaGgát;xøICag EdlRtUv)annaM exported into the cytosol. ecjeTAkñúgsuItUsUl. RNase : A class of enzymes that RNase ARN hydrolyze RNA molecules. ³ fñak;énGg;suImEdleFVIGuIRdUlIsm:UelKul . Robertsonian translocation : A Robertsonian form of chromosomal mistake that bMlas;Ggát;RkUm:UsUm ³ TMrg;énvibtþiRkUm:UsUm Edl involves the fusion of two separate chromosomes. Cab;Tak;TgnwgkarrlaycUlKñaénRkUm:UsUmepSgKñaBIr. rod : Photoreceptor cell in the vertebrate retina specialized to ekasikadMbg ³ ekasikaFܵlBnøWkñúgerTInstVq¥wgkg Edlmanmuxgar function effectively under conditions of dim light. Biessd¾manRbsiT§iPaBkñúgl½kçx½NÐBnøWtic. Roentgen ® : Unit used to X describe the amount of energy r:ugEsn ³ ÉktaeRbIsMrab;BN’nafamBlEdlbeBa©jedaykaMrsIµ deposited in 1 g of air by X-rays or gamma radiation, named after the b¤rsµIkam:aeTAnwgxül;mYyRkam ÉktaenHdak;eQµaHtamGñkrUbviTüaGaLWm:g; German physicist Wilhelm eQµaH Wilhelm Roentgen EdlCaGñkrkeXIjkaMrsµI X. Roentgen who discovered X-rays. Roentgen equivalent man (Rem) : The amount of radiation that will smmUlernhÁinmnusS ³ brimaNénrsµIEdlnwgbNaþl cause the same biological effect as X one roentgen of X-rays. We are eGayman\Ti§BlCIvsa®sþ dUcKñaeTAnwgmYyr:ugEsnénkaMrsµI .eyIg)an exposed to about 10 mrem/month TTYlrgRbEhl 10mrem kñúgmYyExBIrsµIEdlecjBIRbPBFmµCati. from natural sources of radiation.

rolling circle replication or sigma ADN (σσσ) replication : DNA replication sV½ydMeLIgeTVsuicma: ³ sV½ytMelIgeTV EdlcMnuclUtlas; in which the growing point or b¤CMBamsV½ydMeLIgeTVrMuCMuvijRcvak;KMrUBum

S S : See Svedburg coefficient unit. S ³ emIl Svedburg coefficient unit . S phase : During interphase, the S ADN portion of the cell cycle in which vKÁ ³ Epñkénvdþekasika ¬enAkúñgcenøaHvKÁ ¦EdlmankarsMeyaK . DNA synthesis occurs; S refers to S ADN the synthesis of DNA. sMedAeTAelIkarsMeyaK . S nuclease : A deoxyribonuclease 1 S that cuts and degrades nuyekøGas 1 ³ CaGg;suImedGuksuIrIbUnuyekøGasEdlkat; nigbMEbk single-stranded molecules of DNA. m:UelKulRcvak;maçgrbs; ADN . saliva : A fluid produced by the salivary glands in the mouth Twkmat; ³ FaturavEdlbegáItedayRkeBjTwkmat;enAkúñgmat; Edl containing water, salts, mucin and salivary amylase. bgáeLIgedayTwk GMbil muysIun nigGamILasTwkmat;. salivary amylase : An enzyme present in saliva that breaks starch GamILasTwkmat; ³ Gg;sIummanenAkñúgTwkmat; EdlbMEbkm:UelKul molecules into smaller molecules. GamIdugeGayeTACam:UelKultUc². salivary gland : A group of secretory cells that produce saliva. RkeBjTwkmat; ³ RkumekasikabeBa©jEdlplitTwkmat;. salts : Ionic compounds formed from a reaction between an acid GMbil ³ smasFatuGuIyu:gEdlekItBIRbtikmµrvagGasIutnig)as. and a base. samara : A type of winged fruit maple found in maple trees. Epøsøab ³ RbePTEpøEdlmansøabénrukçCati . saponification : Basic hydrolysis of an ester (usually a lipid) to form sab‘Ukmµ ³ GIuRdÚlIseGEsÞ ¬CaTUeTAlIBIt ¦edIm,IbegáItGMbilénGasIutxøaj; the salt of the fatty acid (soap) and the alcohol (glycerol). ¬sab‘UdMu ¦nigGal;kul ¬KøIesr:ul ¦. saprobe : Organisms that feed on dead organic matter; decomposer. saRbÚb b¤GñkbMEbk ³ Pavrs;EdlciBa©wmCIvitedaysarFatusrIragÁEdl gab;. saprophyte : an organism that absorbs its food from dead or saRbÚPIt ³ Pavrs;EdlRsUbykGaharBIsarFatusrIragÁEdlgab; b¤ decaying organic matter. rlYy. sapwood : The younger portion of a woody stem that can conduct sabvUt ³ Epñkx©IénedImeQIEdlGacdwknaMTwk)an. water. sarcolemma : The thin noncellular outer membrane of sakUeLm ³ PñasesþIgminEmnCaekasikaxageRkA rbs;PIbsac;duMqñÚt. striated muscle fibers. sarcomere : The region of a Z Z myofibril from one Z band to the sakUEm ³ Epñkrbs;PIbsac;duMbnÞH mYyCYbCamYybnÞH mYyeTot. next; the contractile unit of a muscle cell. ÉktakRnþak;rbs;ekasikasac;duM. satellite DNA : DNA that forms a ADN : ADN ADN minor band when genomic DNA is rNb EdlbgáCaRkumtUcenAeBl esNUmRtUv)anEjk centrifuged in a cesium salt ADN gradient. This DNA usually RbTajecjkñúgkMhab;GMbilessüÚm . CaFmµta enHmantMnlMdab; consists of short sequences xøI²eRcIndgkñúgesNUm. repeated many times in the genome.

saturated : A term used to describe an organic molecule that Eq¥t ³ BaküeRbIsMrab;erobrab;BIm:UelKulsrIragÁmYyEdlKµansm<½n§BIrCan; has no double bonds and that has the maximum number of hydrogen nigmanGatUmGIuRtUEsneRcInbMputP¢ab;eTAnwgGatUmkabUnnImYy². atoms bonded to each carbon atom. saturated fatty acid : Fatty acid that has no carbon to carbon double GasIutxøaj;Eq¥t ³ GasIutxøaj;EdlKµankabUncgsm<½n§BIrCan;CamYyKña. bonds. saturated hydrocarbon : Hydrocarbon containing only GIuRdÚkabYEq¥t ³ GIuRdÚkabYEdlmanEtsm<½n§mYyCan;rvagkabUnnigkabUn. single carbon to carbon bonds. savanna : A grassland with scattered trees. Many savannas are valesµag ³ dIvalesµAEdlmanedImeQIduHray)a:y ehIyPaKeRcIn located in tropical or subtropical areas. zitenAkñúgtMbn;RtUBic b¤Ek,rRtUBic. scales : Small, hard, overlapping structures covering the surface of Rska ³ TMrg;EdlmanragtUc rwg RtYtelIKña EdlRKbdNþb;elI bony fish. épÞxøÜnRtIq¥wg. scanning electron microscope : An electron microscope that mIRkÚTsSn_eGLicRtÚnicesán ³ mIRkUTsSn_eGLicRtUnicEdlbgðajrUbPaB displays an image of an object’s surface using a beam of electrons rbs;épÞvtßúmYy edayeRbIBnøWkaMrsµIeGLicRtugqøúHemIlvtßúenaH. scan the objects. scapula : The shoulder blade. Part of the pectoral girdle. See p. 321. q¥wgsøabRbecov ³ q¥wgsµasmEb:t. Epñkénq¥wgRkvat;sµa. emIlTMBr½ 321 . scapulocoracoid cartilage : In elasmobranchs elasmobranchs and certain q¥wgx©IsáaBuLÚkUra:kUGIut ³ cMeBaHRtIq¥wgx©I nigstVq¥wgkg primitive gnathostomes, the single solid element of the pectoral manfÁamCan;edImxøH Caq¥wgx©IeTald¾rwgmaMénq¥wgRkvat;sµa. girdle. scarification : The cutting, abrading, or otherwise softening of CMenaH ¬sMbkRKab; ¦ ³ karkat; karxat; b¤kareFVIeGaysMbkRKab;Tn;; the seed coat to induce the seed to germinate. edIm,IeGayRKab;duHBnøkeLIg. scavenger : An animal that feeds on dead organisms. stVsIusaksB ³ stVEdlsIuPavrs;Edlgab;. SCE : See sister chromatid SCE sister chromatid exchange exchange. ³ emIl . schizocoely : Coelom formation accomplished by a split in the sIusUsWlI ³ karbgábegáItsWLÚmedaykarxN½ÐEckkñúgemsUEDmenA mesoderm during embryonic (Protostomes) development of some animals dMNak;lUtlas;énGMRb‘Íy:ugstVxøH . (protostomes). science : A process or way of arriving at a solution to a problem viTüasaRsþ ³ dMeNIrb¤viFIrkcMelIy b¤karyl;dwgBIehtukarN_kñúg or understanding an event in nature using the scientific method. FmµCatiEdleRbIviFIviTüasaRsþ. scientific law : A uniform or constant feature of nature c,ab;viTüasaRsþ ³ lkçN³ÉksNæan b¤sißitesßrénFmµCatiEdlKaMRT supported by several theories. edayRTwsþICaeRcIn.

scientific method : A way of analyzing the physical universe; viFIviTüasa®sþ ³ viFIviPaKBIrUbsakl. karsegátRtUv)aneRbIedIm,IbegáIt observations are used to construct a hypothesis that is tested by smµtikmµEdlRtÚv)aneFVIetsþedaykarsegátb¤BiesaFn_. smµtikmµenaH observations or experiments; the RtUv)anTTYlyk rWminTTYlykEp¥kelIGMNHGMNagBiesaFn_. GIVEdlmin hypothesis is accepted or rejected based on experimental evidence. GacepÞógpÞat;)anminGacRtUv)anTTYlykCaEpñkénsmµtikmµviTüasa®sþeT. Something that cannot be verified cannot be accepted as part of a scientific hypothesis. scientific notation : Process of writing a measurement or com- sBaØaNviTüasaRsþ ³ lMnaMénkarsresrBIrgVas;b¤lT§plEdl)an puted result as a number between 1 and 10 times a power of 10. It is KNnadUcCacMnYnBI 1 eTA 10 KuNnwgsV½yKuNén10. vamanRbeyaCn_ particularly useful in rounding off edayELkkñúgviFIsMrYlTsPaK ehIynwgkarbgðajlT§plBIcMnYnsmRsb and presenting results to the appropriate number of significant éntYelxsMxan;². figures. scientific theory : A hypothesis that is supported by experimental RTwsþIviTüasaRsþ ³ smµtikmµEdlKaMRTedayGMnHGMNagBiesaFn_. evidence. scintillation : Flash of light given off when an atom is struck by a karbeBa©jBnøW ³ kareGayBnøWenAeBlEdlGatUmRtÚv)anb:Hedaypg; nuclear particle or gamma ray. énéNVy:Ub¤kaMrsIµháama:. scintillation detector : Detector used principally for detecting ]bkrN_emIlkarbeBa©jBnøW ³ ]bkrN_EdlRtÚv)aneRbIedIm,IemIlkaMMrsIµ gamma rays. Photons striking the detector knock electrons from háama:. pUtugEdlb:Hnwg]bkrN_)aneFIVeGayvabeBa©jeGLicRtúgecjBI atoms; as these electrons fall back GatUm. enAeBlEdleGLicRtúgFøak;eTArkTItaMgEdlmanfamBlTabkñúg to lower energy positions in their atoms, light is given off. This light GatUmrbs;va BnøWRtUv)anbeBa©j. BnøWenHRtÚv)ansegátemIledaybMBg; is observed by a photomultiplier tube, and the passage of the photomultiplier ehIykarqøgkat;énPaKl¥itRtÚv)ankt;RtaTuk. particle is recorded. scion : The shoot or bud from one plant that is attached to the root ExñgbMe)A ³ RtYy rWBnøkEmkEdlykmkBIrukçCatimYy ehIyRtUv)anyk stock of another plant in grafting. eTAtP¢ab;nwgTMrExñgbMe)Arbs;rukçCatimYyeTot enAkñúgkarbMe)A. sclereids : Sclerenchyma cells found in tissues varying from ekøerGIut ³ ekasikaekør:g;suIm EdlmanenAkñúgCalikaEdlERbRbYlBIEpø sapodilla fruits to the hard shells of some nuts. lµúteTAsMbkrwgrbs;RKab;mYycMnYn. sclerenchyma : A plant tissue specialized for strength, support, ekør:g;sIum ³ CalikarukçCatimanmuxgarBRgwg RTRTg; nigkarBarEdlPñas and protection with cell walls thickened by lignin and without eRKageLIgRkas;edaylIjIn. cell contents. sclerotic : The tough outer coat of the eyeball. ekør:UTic ³ PñasrwgxageRkAénRKab;EPñk. scolex : The head of a tapeworm which has hooks and suckers used k,al ³ k,aletBaJ:aEdlmanTMBk; nigQñb; EdleRbIsMrab;P¢ab;eTAnwg for attachment to the gut wall of the host. PñaseBaHevonrbs;FµÜl. scrotum : The pouch that contains the testes and accessory organs in fg;sVas ³ fg;pÞúkBgsVasnigsrIragÁbnÞab;bnSMcMeBaHfnikstVesÞIrEt most mammals. TaMgGs;.

scutellum : The cotyledon of a grass seed; the scutellum is sÁÚetlUm ³ kUTIeldugrbs;RKab;RkamIenEdlmantYnaTIBiesskñúg specialized for absorbing nutrients from the endosperm as the seed karRsUbsarFatuciBa©wmBIGg;dUEs kMbüÚmsrésnaM nig EdlbEnßmTMhMeGayrws. root. secondary metabolism : The metabolism of chemicals that occur emtabUlIsTIBIr ³ emtabUlIssarFatuKImI EdlekItmanmineTogTat; b¤ irregularly or rarely among different plants and that usually kMrnwgekItmankñúgcMeNamrukçCatiepSg²KñaehIyCaTUeTAeKmin)andwgBInaTI have no known metabolic role in kñúgemtabUlIsekasika. cells. secondary oocyte : A cell that : II undergoes meiosis II to produce GUvUsIutTIBIr ekasikaEdleFVIemyY:s edIm,IbegáItkaEm:tjI nigeKalika the ovum and a second polar body. b:UlTI II . secondary protein structure : Helical or pleated structure of a RbUetGuInTMrg;TIBIr ³ TMrg;CaregVlKUfxüg b¤Capñt;;énRbUetGIunEdlbNþal protein that is due to hydrogen bonding between atoms of the mkBIsm<½n§GIuRdÚEsnrvagGatUmTaMgLayrbs;eRKagb:UlIbiubTIt. polypeptide backbone.

secondary sex characteristics : Characteristics of the adult male or lkçN³ePTTIBIr/lkçN³ePTbnÞab; ³ lkçN³rbs;mnusSRbus b¤RsI female, including the typical shape that develops at puberty: broader EdleBjv½y rYmmanragerAtYy:ag EdllUtlas;enAeBleBjv½y ³ shoulders, heavier long-bone sµarIkFM sac;dMulUtlas;xøaMg duHeramelImux duHeramekøok duHeramRTUg muscles, development of facial hair, axillary hair, and chest hair, nig ERbRbYlbMBg;sMelgcMeBaHburs RtKakragmUl edaHrIkFM nigmankar and changes in the shape of the larynx in the male; rounding of the ERbRbYlRsTab;xøaj;cMeBaHnarI. pelvis and breasts and changes in deposition of fat in the female. secondary sex ratio : The ratio of males to females at birth. smamaRtePTTIBIr ³ smamaRtePTeQaµleFobnwgePTjIenAeBlekIt. secondary spermatocyte : A cell : II that divides in meiosis II to Es

seed ferns : An extinct group of plants that were characterized by bNÑgCatimanRKab; ³ RkumrukçCativinasputBUC EdlsMkal;edaysøwk frond-like leaves and seedbearing structures; classified together in the dUcFagnigTMrg;pÞúkRKab;. RkumbNÑgCatimanRKab;enHRtUv)ancat;fñak;cUl Division Pteridospermophyta eTAkñúgsaxaetrIdUEs1. selection coefficient is 0.1. selection pressures : Those environmental factors that promote sMBaFCMerIs ³ ktþabrisßanEdlbegáInb¤BnüWteCaKC½ykñúgkarbnþBUC or retard reproductive success of a phenotype. énepNUTIbmYy. selectively permeable : The characteristic of only allowing CMrabeRCIs ³ lkçN³EdlGnuBaØatieGayEtsarFatumYycMnYnb:ueNÑaH certain substances to pass through. Edlqøgkat;)an. self-compatible : Refers to the potential for successful sV½ybnþBUC ³ sMedAeTAelIskþanuBlPaBkñúgkarbnþBUCedayeCaKC½y reproduction between flowers of the same plant or between stamens rvagpáaénrukçCatiEtmYy b¤rvagkBaú©MeksreQµalnigkBa©MúeksrjIrbs;páaEt and carpels of the same flower mYy. self-incompatible : Incapable of successful reproduction between sV½ybnþBUCmin)an ³ GsmtßPaBkñúgkarbnþBUCrvagpáaénrukçCati EtmYy flowers of the same plant or between stamens and carpels of the b¤rvagkBa©MeksreQµalnigkBa©MeksrjIénpáaEtmYy. same flower. selfing : In , the fertilization of ovules of a plant by sV½ybgákMenIt ³ cMeBaHesenTicrukçCati CakarbgákMenIténGUvulrbs; pollen produced by the same plant. Reproduction by self-fertilization. rukçCatimYyedaylMGgplitedayrukçCatiEtmYyenaH. karbnþBUCedaysV½y bgákMeNIt. selfish DNA : Refers to DNA that ADN ADN can perpetuate itself by sV½yGtßiPaB ³ sMedAeTAelI EdlmanGtßiPaBCabnþbnÞab; semi-autonomous replication; Transposon transposons are considered to be edaysV½ydMeLIgeTVBak;kNþalsV½yRbvtiþ. RtUv)aneKcat; selfish DNA because they can TukfaCa DNA sV½yGtßiPaBedaysarEtvaGacpøas;TIRkmcMlgrbs;va move copies of themselves to several sites in a genome. eTAkEnøgCaeRcInkñúgesNUmmYy.

self-limiting : A population that levels off before reaching its sV½ykMrit ³ b:UBuyLasüúgEdlbnßykMrit muneBlEdlQaneTAdl; carrying capacity. smtßPaBRTRTg;rbs;va. self-pollination : Pollination that occurs within a single flower. sV½ydMenIrlMGg ³ dMeNIrlMGgEdlekIteLIgenAkñúgpáaEtmYy. self-replication : Refers to the ADN ability of DNA to make exact sV½y-sV½ytMelIgeTV ³ sMedAeTAelIsmtßPaBrbs; kñúgkarbegáIt copies of itself. ADN dUcnwgxøÜnvaedayxøÜnvapÞal;. semen : A liquid made of seminal fluid and sperm. Twkkam ³ sarFaturavEdlekIteLIgBITwkBUCnigEs

sensory neuron : Nerve cell that transmits information from the NWr:Un\RnIÞy_naM ³ ekasikaRbsaTEdlbBa¢ÚnBt’manBIbrisßaneTAxYrk,al environment to the brain or spinal cord. rWxYrq¥wgxñg. sensory palp : Slender organs of taste on the labium and maxillae of ExñgviBaØaN ³ srIragÁCIvðaviBaØaNragravesþIgsßitenAelIbbUrmat;eRkam insects. nigfaÁmrbs;stVl¥it. sepal : One of a group of modified leaves that protects the developing Rtbkpáa ³ RkumsøwkkMENERbEdlkarBarpáaRkBMukMBuglUtlas;. flower bud. septum (plural: septa ): A wall between two cavities as in snÞHx½NÐ ³ Pñasx½NÐenAcenøaHRbehagBIr dUcCadgáÚvxøÜnkg; rWkarEck annelids, or body divisions, as in Chaetognaths chaetognaths, or a crosswall in xøÜndUcCacMeBaH b¤ PñaseRKagkñúgGuIhVrbs;pSit. fungal hypha. sere : The sequence or series of communities that develop in a es‘rIshKmn_ ³ lMdab; rWes‘rIshKmn_ EdllUtlas;kñúgsßanPaBmYy given situation from pioneer to terminal climax communities taMgBIshKmn_QanmuxrhUtdl;shKmn¾mankMritx

sex ratio : The number of males in a population compared to the smamaRtePT ³ cMnYnÉktþ³eQµaleFobnwgcMnYnÉktþ³jIkñúg number of females. b:UBuyLasüúgmYy. sexduction : Transmission of chromosomal genes from a donor karbBa©ÚlEsn ³ karbBa¢ÚnEsnRkUm:UsUmecjBI)ak;etrIGñkeGayeTA bacterium to a recipient cell by the F F factor. ekasikaGñkTTYledayktþa . sex-influenced traits : Characteristics that are dominant in lkçN ³man\T§iBlelI;ePT ³ lkçN³EdllubcMeBaHePTmYy nigGn; one sex and recessive in the other. eg. baldness in men. cMeBaHePTmYyeTot. ]TahrN_³ k,alTMEBkcMeBaHmnusSRbus. sex-limited trait : A phenotypic characteristic that appears only in lkçN ³kMritePT ³lkçN³epNUTIbEdlelceLIgEtenAkñugÉktþ³énePT individuals of one sex. eg. lactation in female mammals, face hair in Cak;lak;mYy. ]TahrN_ ³ karecjTwkedaHcMeBaHfnikstVjImaneram male humans. muxcMeBaHmunsSRbus. sex-linked genes : Genes located X on the X chromosome. EsnCab;ePT ³ EsnEdlsßitenAelIRkUm:UsUm . sex-linked traits : Characteristics determined by genes on the X lkçN ³Cab;ePT ³ lkçN³EdlkMNt;edayEsnsßitenAelIRkUm:UsUm chromosome. eg. red-green colour X blindness. . ]TahrN_ ³ CMgWggwtBN’. sexual intercourse : The mating of male and female. The deposition karrYmePT ³ karBak;KñarvageQµalnigjI. karbBa©ÚlekasikaePT of the male sex cells, or sperm , cells, in the reproductive tract of eQµalb¤EslµÚn ¦ , kMTutKña ¬stVl¥it ¦ , copulation. karrYmrk½S ¬mnusS ¦. sexual reproduction : A method of producing offspring in which karbnþBUCedayePT ³ viFIbnþBUCEdlkaEm:tGabøúÚGIutBIrrlaycUlKña two haploid gametes join to form a diploid zygote. begáIt)anCasIukUtDIbøÚGIutmYy. shaft : A hollow tube that forms the central part of a feather. G½kSsøab ³ bMBg;RbehagenAtambeNþaykNþalsøab. Shine-Dalgarno (SD) sequence : Shine-Dalgarno 5’-AGGAGGU-3’ The nucleotides 5’-AGGAGGU-3’ tMNlMdab; ³ nuyekøGUTIt present in the start codon on ARNm bacterial mRNA that serves as a mankñúgkUdugcab;epþImelI )ak;etrI EdledIrtYCakEnøgPa¢b;rIbUsUm. ribosome binding site. The 16S ARN 16S énÉktargtUcrIbUsUm EdlpÞúknUvtMnlMdab;bMeBjKña CakEnøg RNA of the small ribosomal subunit contains a complementary ARNm RtUvP¢ab;. sequence to which the mRNA binds. short period interspersion : Pattern of genome organization in KMrUcMruHry³eBlxøI ³ KMrUénkartMerobcesNUm Edlkarlatsn§wgén which stretches of single copy ADN DNA (about 1000 bp) are RkmcMlg eTal ¬ RbEhl !000KU)as ¦ RtUv)anBRgayBaseBj interspersed with short segments of CamYynwgbMENk ADN dEdl ² ¬ 300KU)as ¦. KMrUenHRtUv)anRbTH repetitive DNA (300 bp). This pattern is found in Xenopus, eXIjcMeBaHkEgáb Xenopus / mnusS nigPavrs;PaKeRcInEdlRtUv)an humans, and the majority of organisms examined to date. segátBinitürhUtmkdl;eBlenH. short-day plant : A plant that flowers only when the photoperiod rukçCatieBléf¶xøI ³ rukçCatiEdlecjpáaEtenAeBlEdlry³eBléf¶xøICag is shorter than a critical amount. ry³eBlkMnt;.

shortgrass prairie : A type of grassland in the western United valesµAxøI² ³ RbePTvalesµAenAPaKxaglicénshrdæGaemrik Edl States that is relatively dry. manGakasFatus¶Üt. shotgun experiment : The cloning ADN of random fragments of genomic BiesaFn_ sthÁan; ³ kareFVIkøÚnénGgát;esNUm edayécdnü DNA into a plasmid or phage, usually to produce a wide variety eTAkñúg)aøsµItb¤pas EdlCaFmµtaedIm,IbegáItkøÚnxus²KñaCaeRcIn kñúgenaH of clones from which clones of køÚnEdleKcg;)annwgRtUv)aneRCIserIs. specific interest will be selected. sickle-cell anemia : A genetic disease in humans caused by an CMgWeKalikaRkhmragkeNþov ³ CMgWesenTicekItmancMeBaHmnusS autosomal recessive gene, usually fatal in the homozygous condition. EdlbNþalmkBIEsnGn;GUtUsUm nigCaFmµtabNþaleGaysøab;kñúg Caused by an alteration in the l½kçx½NÐGUm:UsuIkUt. CMgWenHbNaþlmkBIkMENERbtMnlMdab;GasuItGamIen amino acid sequence of the beta chain of globin. It causes red blood énRcvak;Ebtarbs;køÚb‘Ín. vabNþaleGayeKalikaQamRkhmmanrag cells to have a twisted ‘sickle’ shape that causes serious problems keNþovrmUcUlKña nigbgábBaaðy:agF¶n;F¶rcMeBaHRbdab;rbt;Qam. for blood circulation. sickle-cell trait : The condition of being heterozygous for sickle-cell lkçN³eKalikaragkeNþov ³ sßanPaBCaeGetr:UsIukUténCMgWeKalika disease. RkhmragkeNþov. sieve area : Part of the wall of a sieve element containing many tMbn;Rbehag ³ EpñkénPñasFatuRbehag Edlmanrn§CaeRcInCakEnøg pores through which the protoplasts of adjacent sieve EdlRbUtU)aøsénFatuRbehagenAEk,r²KñaRtUv)anP¢ab;Kña. elements are connected. sieve cell : A long sieve-element having unspecialized sieve areas ekasikaRbehag ³ FatuRbehagEvg² mantMbn;RbehagminÉkeTs and tapering end walls that lack sieve Plates; sieve cells occur in nigPñascugsþÜcEdlKµanbnÞHRbehag. ekasikaRbehagenHmanenAkñúg the phloem of gymnosperms and pøÚEGmrbs;rukçCatisuImNUEs

significant figures : Digits in a measured or computed number that elxsMxan; ³ elxkñúgrgVas;b¤cMnYnKNnaEdlmansar³sMxan;. kñúgkar are meaningful. Arithmetic operations sometimes artificially KNnanBVnþ CYnkalmankarbEnßmelx. lT§plénplKuNb¤plEck create additional digits. The result elxGacminEdlmanelxxÞg;sMxan;eRcInCagcMnYnTsPaKEdleRbIkñúg of multiplication or division operations may never have more karKNnaeLIy. lT§plénplbUkb¤plsgminRtÚvmanxÞg;elxenABI significant figures than the least certain number used in the eRkayTsPaKeRcInCagcMnYnTsPaKEdleRbIkñúgkarKNna. operation. The result of an addition or subtraction operation may never have more numbers after the decimal place than the least certain number used in the operation. silica : Silicon dioxide. A glassy ³ sIulIsüÚmDIGuksIut. rUbFatuEkvEdlmanrUbmnþ SiO 2. material with the formula SiO 2. sIulIs simian : Refers to monkeys. sVa ³ sMedAelIsVa. simple eye : A light-sensitive ocellus organ in many invertebrates. See EPñkgay ³ srIragÁrYsnwgBnøWénstV\tq¥wgkgCaeRcIn. emIl . ocellus. simple fruit : A type of fruit that develops from a single ovary in a EpøeTal ³ RbePTEpøEdllUtlas;BIGUEveTalénpáamYy. single flower. simple leaf : A type of leaf in which only one blade is attached to søwkeTal ³ RbePTsøwkEdlmanEttYsøwkmYyP¢ab;eTAnwgTgsøwk. the petiole. simple microscope : Single lens magnifier. mIRkUTsSn_Fmµta ³ ]bkrN_BRgIkEdlmanEkvBRgIkmYYy. simple protein : Protein containing only amino acids. RbÚetGIungay ³ RbÚetGIunEdlmanEtGasIutGamIen. SINES : Short interspersed repetitive sequences found in the sIun ³ tMnlMdab;xøI²dEdl²enAlayLMKñakñúgesNUmPavrs;fñak;xçs; genomes of higher organisms, such Alu 300 as the 300-bp Alu sequence. dUcCatMnlMdab; Edlmanman KU)as. single bond : A covalent bond involving a single pair of electrons. sm<½n§mYyCan; ³ sm<½n§kUva:Lg;éneGLicRtugmYyKU. single-factor cross : A genetic study in which a single karbgáat;mYyktþa b¤m:UNUGIRbIDIs ³ karsikSaesenTic EdllkçN³ characteristic is followed from the parental generation to the mYyRtUv)anbBa¢ÚnBICMnan;em)aeTACMnan;kUn. offspring. single-strand binding proteins : Proteins that prevent the fusion and RbUetGIunP¢ab;nwgRcvak;eTal ³ RbUetGIun EdlkarBarkarrlay nigrmUr rewinding of DNA once the double ADN strands are split apart for cUlKñavijén enAeBlEdlRcv:ak;TaMgBIrdac;ecjBIKñasMrab; replication. See p. 318. karsV½ytMelIgeTV. emIlTMBr½ 318 . sink : Where organic solutes such as sugar, that are being transported sIug ³ kEnøgEdlsarFaturlaysrIragÁ dUcCasár ¬RtUv)andwknaM by the phloem, are used or stored. edaypøÚEGm ¦ RtUv)aneRbIb¤rkSaTuk. sinus : Open space in a duct or tubular system. sIunus ³ RbehagrIkFMkñúgbMBg; rWkñúgRbB½n§bMBg;. sinus venosus : A sac just behind the heart in fish and frogs that sIunusEv:n ³ fg;Cab;BIeRkayebHdUgRtI nigkEgáb EdlRbmUlQamenA collects blood as it returns to the heart. eBlvilRtlb;mkebHdUgvij.

siphon : A nozzle-like structure of cephalopod mollusks used for rapid sIupug ³ TMrg;EdlmanragdUck,alTueya Edlsib,IstVsir)aT locomotion. eRbIsMrab;bMlas;TIelOn. siphonophore : A pelagic hydrozoa n hydrozoan which forms colonies in sIupUNUpr ³ Ca ¬BBYksWLg;eter ¦ Edlrs;enABak;kNþal which some individuals are modified as a float. eg. Portuguese rWelIépÞTwk ehIybegáIt)anCakULÚnI EdlÉkt³mYycMnYnbMEpøgdUcCaBUg. Man’o War. ]TahrN_ ³ Portugese Man’o War . sister chromatid exchange (SCE) : A crossing over event which can karbþÚrRkUma:TItbgb¥Ún ³ RBitþikarN_RkUsuIjGUevI EdlGacekIteLIgkñúg occur in meiotic and mitotic cells; involves the reciprocal exchange of ekasikamItUs nigemy:UsEdlrYmcMENkkñúgkarbþÚreTAvijeTAmknUvsMPar³ chromosomal material between RkUm:UsUmrvagRkUma:TItbgb¥Ún ¬P¢ab;edaysg;RtUEmrYmKñamYy ¦. sister chromatids (joined by a common centromere). sister chromatids : A pair of chromatids in a duplicated RkÚm:aTItbgb¥Ún ³ RkUm:aTItmYyKUenAkñúgRkUm:UsUmEdl)anekIneLIgeTV. chromosome. sister group : Group of organisms most closely related to the study Rkumc,g ³ RkumPavrs;EdlTak;Tgya:gCitsñiT§eTAnwgÉktacMENkfñak; taxa, excluding their direct descendants. EdlsikSa edayminrab;bBa©ÚlsnþaneRkaypÞal;rbs;vaeT. site-directed mutagenesis : A process that uses a synthetic kEnøgeFVIeGaymanmuytasüúg ³ dMeNIrEdleRbIGUlIkUnuyekøGUTIt oligonucleotide containing a mutant base or sequence as a sMeyaK man)asmuytg;rWtMNlMdab;muytg;;eFVICaRpajm½r sMrab;bgáeGay primer for inducing a mutation at a manmuytasüúgenAkEnøgCak;lak;mYykñúgEsnEdl)aneFVIkøÚn. specific site in a cloned gene. skeletal muscle : See striated striated muscle 325 muscle, p. 325. sac;dMuCab;q¥wg ³ emIl nigemIlTMBr½ . skeleton : Any structure in an organism that maintains its shape eRKagq¥wg ³ TMrg;sarBagÁkayEdlrkSarUbrag nigRTRTg;ragkayrbs;va. and supports its body. Can be exoskeleton, internal and bony as in vertebrates. GacsßitenAxagkñúg nigCaq¥wg cMeBaHstVq¥wgkg. sUmemIl See also exoskeleton, hydrostatic hydrostatic skeleton, cytoskeleton emIlTMBr½ 321 . skeleton, cytoskeleton, and see p. 321. skin : An organ that forms the outer covering of an animal, often Es,k ³ srIragÁEdlbegáItKMrbsaRBagÁkaystV CaTUeTAmanRska eram having scales, hair or feathers. Consists of an outer epidermis over nigsøab. vabgáteLIgedayRsTab;eGBIEDmxageRkABIelIEDmnigRsTab; a dermis layer and subcutaneous xøaj;eRkamEs,k. fat layer. Skinner box : A chamber used in Skinner : operant conditioning that delivers RbGb; bnÞb;manrgVan;EdleKeRbIkñúgkarbegáIterpøicl½kçx½NÐ. reinforcements. skull : A group of fused, bony plates protecting the brain. See llad¾k,al ³ Rkumq¥wgsMEb:trlaycUlKña EdlmanmuxgarkarBar p. 321. xYrk,al. emIlTMBr½ 321 . sliding-microtubule hypothesis : An explanation for how smµtikmµkUnbMBg;rMkil ³ karBnül;BIrebobEdlRkUm:UsUmRtUv)anrMkil chromosomes are moved during anaphase; this hypothesis holds b¤pøas;TIkñúgvKÁGaNapas. tamsmµtikmµenHfa srésRtyUgGaRkUm:aTic that opposing polar spindle fibers b:UlpÞúyKñarMkilBImçageTAmçag EdlbegáIt)anCakMlaMgmYyEdlrujRcan slide past one another, creating a force that pushes the poles of a b:UlRtyUgGaRkUm:aTiceGayEbkBIKña. spindle apparatus apart.

slime moulds : A group of slime moulds organisms with characteristics of pSit ³ Pavrs;mYyRkum EdlmanlkçN³dUcpSitpg nig both fungi and animals. They can exist as individual amoeboid cells dUcstVpg. vaGacelceLIgdUcCaekasikaGamIb b¤GacCam:aseTal or as a single mass with many EdlmanéNVy:UeRcIn dUcGamIbykSmYy. nuclei like one giant amoeba. slug : See pseudoplasmodium. dMu; ³ emIl pseudoplasmodium . small intestine : A part of the digestive system between the eBaHevontUc ³ EpñkénRbB½n§rMlayGahar cab;BIRkBHeTAdl;eBaHevon stomach and the colon in which most chemical digestion and FM EdlmankarrMlayGaharKImI nigkarRsUbGahareRcInCageK. absorption occur. See duodenum, emIl duodenum, jejunum, illeum nigemIlTMBr½ 322 . jejunum, ileum, and see p. 322. small nuclear ribonucleoprotein ARN (snRNP) : A complex of small rIbUnuyekøGURbUetGIuntUc²kñúgéNVy:U ³ kMpøicm:UelKul tUc² RNA molecules condensed with snRNP specific proteins in the nucleus; a EdlenApþúMKñaCamYyRbUetGuInyfaRbePTenAkñúgéNVy:U. CaÉkta snRNP is the basic unit of a sMxan;rbs; spliceosome . spliceosome. small nuclear RNA (snRNA) : ARN ARN 90 Species of RNA molecules ranging tUc²kñúgéNVy:U ³ RbePTénm:UelKul EdlmanTMhMBI eTA in size from 90 to 400 nucleotides. 400 snRNA snRNAs are associated with nuyekøGUTIt. sßitenACamYyRbUetGuInnigbegáItCaRKab;rIbUnuy- proteins and form ekøGURbUetGuInEdlRtUv)aneKsÁal;faCa snRNP s b¤ : snurps : . ribonucleoprotein particles known as snRNPs or ‘snurps’. smooth muscle (involuntary muscle) : Non-striated muscle that sac;duMrlIg ³ RbePTsac;duMKµanqñÚténsrIragÁxagkñúgCaeRcIndUcCaRkBH is not under conscious control found in many internal organs like eBaHevon nigsrésQamEdlminsßitenAeRkambBa¢arbs;xYrk,al. the stomach, intestine, and blood eFVIkareRbobeFobrvag striated muscle, cardiac muscle nig smooth vessels. Smooth muscle reacts slowly and takes Compare striated muscle . muscle, cardiac muscle. snRNP : See small nuclear snRNP small nuclear ribonucleoprotein ribonucleoprotein. ³ emIl . snurps : See small nuclear RNA snurps small nuclear RNA ( snRNA ) (snRNA). ³ emIl . soap : Detergent consisting of the salt of a long-chain fatty acid. sab‘UdMu ³ sab‘Uem:SAEdlpSMBIGMbilénGasIutxøaj;ExSEvg. society : A group of animals that live together and show a division sgÁm ³ RkumstVEdlrs;enACamYyKña edaybgðajbMENgEckkargar. of labor. : The systematic study of all forms of social sgÁmCIvsaRsþ ³ karsikSaCaRbB½n§BIrGakb,kiriyakñúgsgÁmRKb;rUbPaB behavior, both human and non- human. TaMgmnusSTaMgstV. softwood : Coniferous gymnosperm. sac;eQIes

solid : State of matter in which the material has a definite shape and rwg ³ lkçN³rbs;rUbFatuEdlmanragnigmaDkMnt;c,as;las; kñúgenaH volume in which the molecules are packed tightly together; they m:UelKulCaeRcInRtUv)anP¢ab;Kñay:agENn bu:EnþvamanlMj½renAnwgkEnøg. vibrate in place. solute : The substance dissolved in the solvent of a solution. Faturlay ³ sarFatuEdlrlaykñúgFaturMlayénsUlUsüúg. solute potential : See osmotic osmotic pressure pressure. emIl . solution : Mixture of two or more substances (solvent and solute) that sUluysüúg ³ l,ayénsarFatuBIrb¤eRcIn¬FaturMlaynigFaturlay ¦Edl is clear and uniform throughout. Molecules or ions of solute are føanigÉksNæanTaMgGs;. m:UelKulb¤GIuy:ugénsarFaturlayRtÚv)an dispersed evenly throughout the BRgayesµIKñaTaMgGs;kñúgl,ay. mixture. solvent : Pure substance in which another material (the solute) is FaturMlay ³ sarFatusuT§ EdlkñúgenaHFatudéTeTot¬Faturlay ¦ dissolved. RtÚv)anrMlay. soma : The cell body of a neuron, which contains the nucleus. tYekasika b¤sUma: ³ tYekasikaNWr:UnEdlpÞúkENVy:U. somatic (voluntary) nervous system : Motor neurons that RbB½n§RbsaTsUm:aTic rWRbB½n§RbsaTqnÞ³ ³ NWr:UnclkrEdlP¢ab; connect the central nervous system to striated or skeletal muscles. RbB½n§mCÄmNÐlRbsaTeTAsac;dMuqñÚtb¤sac;dMuCab;q¥wg. somatic (adj) : Refers to the body, such as somatic cells in contrast to lUtlas; ³ sMedAeTAelIsarBagÁkay dUcCaekasikalUtlas; germ cells. EdlpÞúyBIekasikabnþBUC. somatic cell : All of the body cells except the germ cells. ekasikalUtlas; ³ ekasikarbs;sarBagÁkayTaMgGs; elIkElgEt ekasikabnþBUC. somatic cell genetics : The use of cultured somatic cells to esenTicekasikalUtlas; ³ kareRbIekasikalUtlas;EdlbNþúH investigate genetic phenomena by parasexual techniques, e.g. edIm,ItamdanRsavRCav)atuPUtesenTic edayviFI)a:r:asic. ]TahrN_ ³ construction of hybrid cells and karbegáItekasikaGuIRb‘Ít nigkarbMe)AéNVy:U. nuclear transplantation. somatic mutation : A mutational event occurring in a somatic cell. muytasüúgekasikalUtlas; ³ RBwtþikarN_muytasüúgEdlekIt In other words, such mutations cannot be inherited. eLIgkñúgekasikalUtlas;. mü:agvijeTot muytasüúgrebobenHminGac CalkçN³tMnBUC)aneT. somatic pairing : The pairing of homologous chromosomes in karpÁÚekasikalUtlas; ³ karpÁÚRkUm:UsUmGUm:ULÚkkñúgekasikalUtlas;. somatic cells. somite : Member of a series of paired segments of the embryonic sUmIt ³ Éktaénes‘rIGgát;KUénemsUEDmxagxñgGMRb‘Íyu:grbs;stVq¥wgkg. dorsal mesoderm of vertebrates. sorus : A cluster of sporangia found on the underside of fern sMnuMs,:r:g; ³ cegáams,:r:g;EdlsßitenAEpñkxageRkamFagsøwkbNÑgÁCati. fronds. SOS response : The response that SOS activates enzymes to repair dam- cMelIytb ³ kareqøIytbEdleFVIeGayGg;suImskmµeLIgedIm,I aged DNA in E. coli. It involves ADN E.coli cutting a repressor and activating a CYsCul EdlxUcxatkñúg . varYmcMENkkñúgkarkat;GñkraraMgnig series of genes involved in DNA kareFVIeGayskmµnUvesrIEsnEdlrYmcMENkkñúgkarCYsCul ADN . repair.

source : Where organic compounds such as sugar are being RbPB ³ kEnøgEdlsmasFatusrIragÁ ¬dUcCasár ¦RtUv)anbegáIteLIgnig made and loaded into the phloem. pÞúkeTAkñúgpøÚEGm. Southern blotting : A procedure Southern ADN by which fragments of DNA are karpþit ³ viFImYyEdlGgát; RtUv)anbMEbkecjBIKña separated by gel electrophoresis, gel electrophoresis ADN transferred to a filter paper, and eday rYcepÞreTARkdastMrg ehIypÁÚCamYy probed with DNA that is EdlbMeBjKñaeTAnwgEsnEdleKcg;)an. TItaMgénEsneKaledARtUv)anrk complementary to the gene of interest; the location of the target eXIjedaysarvakøayCaviTüúskmµenAeBl probe P¢ab;va. gene is found because it becomes radioactive when the probe anneals emIl northern blotting, western blotting . to it. See northern blotting, western blotting. spacer DNA : DNA sequences DNA ADN found between genes, usually cenøaH ³ tMnlMdab; sißtenAcenøaHEsn EdlCaFmµtaCaGgát; repetitive DNA segments. ADN dEdl². specialized transduction : Genetic transfer of only specific host genes dMNwknaMEsnÉkeTs ³ karbBa©ÚnesenTicénEsnFµÜlyfaRbePT by transducing phages. EtmYyKt;edaykarbBa©Únpas. speciation : The evolution of two or more new species by the kMNRbePT ³ vivtþn_eTACaRbePTBIrrWeRcInedaykarEbkecj splitting of one ancestral species. BIRbePTbuBVmYy. species : A group of similar organisms capable of mating and RbePT ³ RkumPavrs;RsedogKñaEdlGacbgáat;KñanigbegáItkUnecA)an. producing fertile offspring. species diversity : The number of species and the number of nanaPaBénRbePT ³ cMnYnRbePT nigcMnYnÉktþ³enAkñúgRbePTmYykñúg individuals per species in an ecosystem. zanRbB½n§. specific dynamic action (SDA) : : The amount of energy required to GMeBIfamBlyfaRbePT brimaNfamBlEdlRtUvkaredIm,IrMlay digest and assimilate food. SDA is SDA equal to approximately 10% of nigsmankmµGahar. manRbEhl 10°énfamBlTTYl your total daily energy intake. )anral;éf¶. specific gravity : Ratio of the mass of a sample of material to the mass PUriBlyfaRbePT ³ pleFobénma:srbs;rUbFatuKMrUmYyeTAnwgma:s of the same volume of water. rbs;TwkEdlmanmaDdUcKña. specific heat : Number of joules 1oC required to change the temperature kMedAyfaRbePT ³ cMnYnsU‘lEdlRtÚvkaredIm,Ipøas;bþÚrsIutuNðPaB of 1 g of a material 1 oC. énrUFatumYyRkam. speciose : Refers to a taxon that contains a large number of species. es

spermatids : Haploid cells produced by spermatogenesis that Es

spiracle : 1. A small opening through which air enters a rn§degðIm ³ 1- rn§tUcmYysMrab;xül;cUleTAkñúgxøÜnrbs;GakRtUb:Utrs;enA terrestrial arthropod. 2. The external opening to the trachea. elIeKak. 2-rn§xageRkAénbMBg;xül;. spiral cleavage : Pattern of cell 45 ° division in which cleavage planes cMENkrages<ó ³ KMrUcMENkekasika Edlbøg;cMENkmanmMu are at 45 o to the animal-vegetal axis of the egg. eTAG½kSbBaÄrrbs;s‘ut. spirillum ( pl. spirilli) : Spiral- shaped bacteria. es,órIlum ³ )ak;etrIEdlmanrages

sporophytic self-incompatibility : A type of self-incompatibility that sV½ybnþBUCmin)anéns,:r:UPIt ³ sV½ybnþBUCmin)anmYyRbePT is imposed by sporophytic tissues or organs; an example would be EdlbNþalmkBI srIragÁb¤Calikas,:r:UPIt. ]TahrN_³ karbnþBUCmin)an incompatibility that is imposed by EdlbgáeLIgedaysÞicm:aEdlCaTMrg;s,:r:UPIt. the stigma, which is a sporophytic structure. sporulation : The formation of spores. A form of asexual kMNs,: ³ karbegáIts,:. TMrg;énkarbnþBUCeday\tePT Edl reproduction in which specialized cells become surrounded by a ekasikaÉkeTsRtUv)anrMuBT§½edayPñaskarBarrwg ehIybnÞab;mkvapþac; strong, protective coat (spores) and ecjBIekasikaemrbs;va. kNs,:enHmanCaTUeTAcMeBaHpSit. then separate from the parent. Common in fungi. spring wood : See early wood . sac;eQIenAniTaXrdUv ³ emIl early wood . squamation : Scaly covering of the body. kMNRska ³ KMrbsarBagÁkayCaRska. stabilizing selection : A process that maintains traits that are CMerIsefr ³ dMenIrEdlrkSalkçN³rbs;Pavrs;EdlQñHenAkñúgbrisßan successful for an organism in its environment. rbs;va. stable electron configuration : Complete complement of outer rUbsNæaneGLicRtugzitefr ³ karbMeBjeBjeljéneGLicRtúg group s and p electrons. Often s p referred to as a noble-gas electron RkumRsTab;eRkA nig . Cajwkjab;sMedAelIkarbMeBjeGLicRtúg complement. elI]sµ½nkMr. stable equilibrium phase : A period of time during population dMNak;kalefrb¤nwg ³ ry³eBlénkarlUtlas;rbs;b:UBuyLasüúgEdl growth when the number of individuals entering the population cMnYnÉktþ³ekItnigcMnYnÉktþ³søab;esµIKµaeFIVeGayb:UBuyLasüúgenAefr. and the number leaving the population are equal, resulting in a stable population. stable isotope tracing : A technique based on the typical ratio kartamdanGIusUtUbzitefr ³ bec©keTsEdlBwgEp¥keTAelIsmamaRt of carbon 12 to carbon 13 in tissue samples, which enables ecologists rvagkabUn 12 nigkabUn 13 enAkñúgCalikaKMrU EdleFVIeGayGñkeGkULÚsuI to determine food sources and GackMNt;)annUvRbPBnigkareRbIR)as;GaharenAkñúgbNþajGahar. consumption in food webs. stalk cell : One of two cells produced when the generative cell ekasikae)aøklMGg ³ ekasikamYykñúgcMeNamekasikaBIrEdlRtUv)an of a gymnosperm male gametophyte divides. Immediately plitenAkñúgekasikabgákMeNIténkaEm:tUPIteQµalrbs;suImNUEs

staminate plant : An individual plant whose flowers bear stamens rukçCatieQµal ³ Éktþ³rukçCatiEdlpáarbs;vamankBa©úMeksreQµal b:uEnþ but not carpels; a “fruitless” mulberry is an example of a plant KµankBaú©MeksrjIeT. edImmnEdlKµanEpøKWCa]TahrN_rukçCatieQµal. that is exclusively staminate ¬edImmnGacbnþBUC)anEtenAeBlEdlRKab;lMGgRtUv)andwknaMeTAkan; (mulberries can reproduce only when pollen is transferred to a rukçCatiEdlmaneksrjI ¦. carpellate plant). standard deviation (s) : A measurement of the amount of KMlatsþg;da ³ CargVas;brimaN ERbRbYlkñúgTinñny½Edl)anmkBI variation in data from a population. Calculated from the square root of b:UBuyLasüúgmYy. eKKNnaecjBIrwskaerénva:rüg;. KMlatsþg;daCa the variance. Standard deviation is FmµtaRtUv)anbgðajedaytMélmFüm. usually stated with the mean. standard error (SE) : An estimate of the standard deviation of the lMeGogsþg;da ³ karRbmaNénKMlatsþg;damFüménKMrUeRcIn means of many samples, calculated s ( n) from the standard deviation (s) EdlKNnaecjBIKMlatsþg;da ¬ ¦EckedayrwskaeréncMnYnÉktþ³KMrU . divided by the square root of the SE = s / √ n number of individuals in the ]TahrN_ tMélkñúgKMrU ( n= 7 ) 48 , 27 , 36 , 52 , 35 , 41 , 33 sample (n). SE = s/ √n eg. Values in sample (n = 7) 48, mFüménKMrU X= 38,86 27, 36, 52, 35, 41, 33 mean of sample X = 38.86 standard temperature and o O C (273 K) pressure (STP) : Conditions of sItuNðPaBnigsMBaFsþg;da ³ l½kçx½NÐénsItuNðPaB nig o O C (273 K) and 1 atm pressure 1 atm 760 mmHg) (760 mmHg) standardized sMBaF ¬ RtUv)ansþg;dakmµTUTaMgBiPBelak. worldwide. stapes : The ear bone that is attached to the oval window. q¥wgQñan; ³ q¥wgRtecokEdlP¢ab;eTAnwgrn§ragBgRkeBI. starch : A carbohydrate made of hundreds to thousands of glucose GamIdug ³ kabUGIuRdatbgáeLIgedaym:UelKulKøúykUsBIrab;ryeTArab;Ban; molecules used as a food storage molecule by plants. It has two EdleRbICam:UelKulGaharbMrugedayrukçCati. vamanTMrg;BIr KWRcvak;Rtg; forms: straight chains called ehAfaGamILas nigRcvak;EbkExñgehAfaGamILÚbuicTIn. amylase, and branched chains called amylopectin. See starch- sUmemIl starch branching enzyme . branching enzyme. starch phosphorylase : A type of enzyme that cuts a molecule of sþacpUsVrILas ³ Gg;suImmYyRbePT Edlkat; KøúykUsmYymU:elKul glucose from one end of a glucose polymer by phosphorylating the BIcugmçagrbs;b:UlIEmKøúykUs edaybEnßmpUsVreTAKøúykUsEdlRtUv)an glucose that is removed from the ykecjBIRcvak;. chain. starch test : An identification test involving the addition of iodine etsþGamIdug ³ kareFVIetsþrkvtþmanGamIdugedayeRbIsUluysüúg solution. A blue/black colour indicates starch. GuIy:Ut. kalNasarFatuenaHeLIgBN’exov rWexµA enaHbBa¢ak;fa manvtþmanGamIdug. starch-branching enzyme (SBEI) : A type of enzyme that converts Gg;sIumeFVIeGayGamIdugEbkEmk ³ Gg;suImmYyRbePTEdlbMElg straight chains of amylose to the “I” branched polymers of amylopectin; Rcvak;GamILÚsRtg;eTACab:UlIEmGamILÚbiucTInEbkExñg. GkSr “I” refers to an iso-form of the sMedAeTAelITMrg; iso-form rbs;Gg;suImenaH. enzyme.

start codon : 1. The DNA base ATP ADN sequence ATG that begins the kUdugcab;epþIm ³ 1- tMNlMdab;)as én Edlcab;epIþm process of transcription into ARN - AUG mRNA. 2. The mRNA base dMeNIkarcMlgRkmeGayeTACa naMsar. 2 tMNlMdab;)as r sequence AUG that begins the én ARN naMsar Edlcab;epIþmdMeNIrkarbkERbeGayeTACaRbUetGIun. process of translation into protein. state of matter : One of the forms in which matter can exist. The lkçN³rbs;rUbFatu ³ TMrg;mYyEdlrUbFatuGacman . rUbFatumanTMrg;bI three most common are solid, liquid, or gas. CaTUeTA KWrwg rav nig]sµ½n. statocyst : A sense organ that gives awareness of orientation of sþatUsIus ³ srIragÁviBaØajEdleFVIeGaydwgBIkartMrg;TisxøÜneTA the body to gravity. nwgTIRbCMuTMgn;xøÜn. stele : The central vascular cylinder of roots and stems. EsÞl ³ bMBg;srésnaMkNþal rbs;rwsnigedIm. stem : A plant organ specialized for conducting water and minerals edIm ³ srIragÁrukçCatiEdlmanmuxgardwknaMTwk nigsarFatuEr:eLIgBIrws up from the roots and food down from the leaves. nigdwknaMGaharcuHBIsøwk. stem name : First part of the element name that provides enough eQµaHedIm ³ EpñkdMbUgéneQµaHrbs;FatuEdlpþl;Bt’manRKb;RKan; edIm,I information to identify the element in a compound name. The stem kMNt;FatuenaHkñúgeQµaHsmasFatumYy. ]TahrN_³ eQµaHedImrbs; name of sulfur, for example, is sulfur KWsulf-. dUecñHsmasFatueTVPaKénGIuRdÚEsnnigs

sterol : A compound derived from six isoprene units linked together esþr:ul ³ smasFatuEdlmanRbPBmkBIÉktaGIusUERbnR)aMmYyP¢ab;Kña in a multiple-ringed structure; β- beta-sitosterol is an example of a kñúgTMrg;rgVg;CaeRcIn. suItUesþr:ulCa]TahrN_BIesþr:ulrukçCati plant sterol; cholesterol is a widely cMENkÉkUelesþr:ul KW]TahrN_BIesþr:ulstV. known example of an animal sterol. sticky end : See cohesive end. emIl cohesive end . stigma : 1- The surface of a carpel E. that receives pollen grains; The tip sÞicm:at ³ épÞrbs;eksrjIEdlTTYlRKab;lMGg. of the pistil; the place where pollen grains germinate. 2- a photosen- cugrbs;kBa©MúeksrjI. kEnøgEdlRKab;lMGgduHBnøk. sitive eyespot found in certain 2- sÞicm:a ³ sñamEPñkEdlrYsnwgBnøWEdlmancMeBaHRbePTsaraymYy kinds of algae. cMnYn. stimulant : A drug that increases the activity of the central nervous fñaMdas;RbsaT ³ fñaMEdlbegáInskmµPaBRbB½n§mCÄmNÐlRbsaT. system. stimulus : Any change in the surroundings that causes a reaction rMejac ³ bMErbMrYlmCÄdæanCMuvij EdleFIVeGayPavrs;manRbtikmµ. in an organism. stipe : The stalk of a nonvascular plant. edIm ³ edImrbs;rukçCatiKµansrésnaM. stipule : Small leaf-like growths found at the base of some leaves. xñaysÞb ³ EpñklUtlas;dUckUnsøwkenAKl;søwkmYycMnYn. stock : The rooted plant used in grafting. TMrExñgbMe)A ³ Epñkrbs;rukçCatiEdlmanrws eRbIsMrab;bMe)A. Stock method : A method of Stock naming compounds containing viFI ³ viFIdak;eQaµHsmasFatu manpÞúknUvFatuEdlmanlkçN³ elements that can have various oxidation states. Oxidation states GuksIutkmµxus²Kña. lkçN³GuksIutkmµRtUv)anbgðajedayelxrU:muaMg are indicated by Roman numerals Cab;bnÞab;BIeQµaHrbs;FatuenaH. ]TahrN_³ Fe0 KWEdk (II) GuksuIt. immediately following the name of the element. For example, Fe0 is iron (II)oxide. stolon (runner) : 1. A horizontal stem that grows along the surface sþÚLúg ³ 1- edImedkEdlduHRsbnwgépÞdI sMrab;karbnþBUCy:agrh½s. of the ground for rapid vegetative strawberry reproduction. eg. strawberry 2. A ]TahrN_ ³ . 2- GIuhVepþkcMeBaHpSit. horizontal hypha in fungi. stoma : A mouthlike opening. Pores found in the leaves of sþÚma:t ³ RbehagEdlmanlkçN³dUcCamat;. rn§enAnwgsøwkrukçCatiman vascular plants whose size is controlled by guard cells. srésnaM EdlTMhMrbs;vaRtUv)anRtYtBinitüedayekasikakarBar. stomach : A hollow organ that receives food and where the RkBH ³ srIragÁRbehagkñúgEdlTTYlykGahar nigCakEnøgEdldMeNIr process of digestion begins. Its , muscular walls secrete pepsinogen, rMlayGaharcab;epþIm. Pñassac;dMurbs;vabeB©ajbiubsIuNUEsn hydrochloric acid and mucin, then GasIutkørIRDic nigmuysIun bnÞab;mkcab;epþImkinrMlaymuneBlbBa¢Ún begins digestion before passing the chyme through the pyloric GaharTaMgenaH ¬sIum ¦qøgkat;TaVreRkamRkBHeTAkñúgeBaHevontUc. sphincter to the small intestine. See p. 322. emIlTMBr½ 322 .

stop codon , nonsense codon or ARN termination codon : Three RNA kUdugsþúb rWkUdugbBa©b; ³ )as bI EdlmincMlgRkmeTACaGasuIt- bases that do not code for an amino acid and cause the termination of GamIeneT bu:EnþbNþaleGaymankarbBa©b;karbkERbRkmkñúgkMLúgeBl translation during protein sMeyaKRbÚ:etGIn. mankUdugsþúbbIRbePT Kw ³ UAA, UAG, UGA . synthesis. There are three stop codons; UAG (amber codon), UAA (ochre codon), or UGA (opal codon). strain : A group of organisms within a species or variety, which BUC ³ RkumPavrs;kñúgRbePTmYy EdlxusKñaEtedaylkçN³tictYc is only different in minor characteristics. b:ueNÑaH. stratification : The exposure of seeds to extended cold periods dMNuHCaRsTab; ³ karsMdilRKab;eGayb:HnwgGakasFatuRtCak;y:ag before they will germinate at warm temperatures. yUr muneBlvaduHBnøkenArdUvekþA. stratigraphy : Classification, correlation, and interpretation of RsTab;viTüa ³ cMENkfñak; karCab;Tak;TgKña nigkarbkRsay stratified rocks. RsTab;fµ. stratum (pl. strata) : A horizontal layer or division of a biological RsþatTum ³ RsTab;Can;fñak;énshKmn¾CIvsaRsþEdlbgðajRsTab; community that exhibits strata) stratification of habitats Can;fñak;énkEnøgrs;enA ¬eGkULÚsuI ¦. ¬Bhuvcn³ . (ecological). stretch receptor : The receptor for detecting muscle stretch. Stretching FµÜlrla ³ FµÜlsMrab;RtYtBinitüBIkarrlarbs;sac;dMu. karrlanUvsac;dMu of surrounding muscle causes nerves in the stretch receptor to CMuvijeFVIeGayekasikaRbsaTenAkñúgFµÜlrlaeP£aceGaymankarkRnþak;sac; stimulate muscle contraction thus dMu dUecñHeFVIeGaymanerpøicrla. ]TahrN_³ rMejack,alCgÁg;. causing the stretch reflex. stretch reflex : An automatic response to sudden stretching of erpøicrla ³ tMNbedaysV½yRbvtþirbs;sac;dMu edayrlaPøam² muscle that protects it from stretch receptor damage. See stretch receptor. EdlkarBarvaBIkarxUcxat. sUmemIl . striated muscle (skeletal muscle) : Voluntary muscle that moves sac;dMuqñÚt ¬sac;dMuCab;q¥wg¦ ³ sac;dMuqnÞ³EdleFIVeGayq¥wgmanclna bones. Muscle fibres are striped with many nuclei and sarcomeres. sréssac;dMumanlkçN³qñÚtCamYynwgéNVy:U nigsakUEmCaeRcIn. They can contract rapidly. See sac;dMuenHGack®nþak;)anya:grh½s. emIlTMBr½ 325 . p. 325. strobila : A linear sequence of similar animal structures, such as RsþÚb‘ÍLa ³ tMNlMdab;CaExSénTMrg;Rsedog²Kñarbs;stV the segmented body of a tapeworm. EdlmanlkçN³dUcCaxøÜnx½NÐCakg;rbs;etnj:a. strobilus, compound : An axis with lateral branches bearing RsþÚb‘Ílws¬smas¦ ³ G½kSmYymanEmkcMehogEdlpÞúks,:r:UPIl. sporophylls. strobilus, simple : An unbranched axis bearing sporophylls. RsþÚb‘ÍlwsFmµta ³ G½kSKµanEmkpÞúks,:r:UPIl. stroma : Enzyme-containing fluid that fills chloroplasts. The region RsþÚm:a ³ sarFaturavEdlmanGg;suImsßitenAkñúgkør:U)aøs. CaEpñkenAkñúg within a chloroplast that has no chlorophyll. kør:U)øasEdlKµankør:UPIl. stromatolite : A rock-like mound formed by cyanobacteria. Similar RsÚþm:atUlIt ³ dMudUcfµEdlbgáedaysüaNU)ak;etrI. vamanlkçN³dUc fossils have been found in pre- cambrian rocks 3 billion years old. pUsuIlEdr EdleKrkeXIjenAkñúgfµbuerkMRb‘Íeyog EdlmanGayukal bIlanqñaMmkehIy.

strong acid : Molecule or ion with a greater tendency to give up GasIutxøaMg ³ m:UelKul b¤GIuy:ugEdlmanTMenarkñugkare)aHbg;GIuy:ug + hydrogen ions than H 30 . eg. GIuRdÚEsnxøaMgCagGIuRdÚj:Úm. ]TahrN_ ³ H2S0 4, HN0 3, HCl. H2S0 4, HN0 3, HCl. structural formula : A method of showing the bonds between atoms rUbmnþeRKag ³ viFIbgðajsm<½n§rvagGatUmnigkartMerobGatUmkñúg and the arrangement of the atoms perspective formula within a molecule. See perspective m:UelKul. emIl . formula. structural gene : A gene that encodes the amino acid sequence EsnTMrg; ³ EsnEdlmanRkmsMrab;kMnt;tMnlMdab;GasuItGamIenén of a polypeptide chain. Rcvak;bU:lIbuibTItmYy. structural polysaccharide : A polysaccharide that holds cells and b:UlIs;karItTMrg; ³ b:UlIsakarItEdlRTRTg;ekasika nigsarBagÁkay organisms together; cellulose is the most abundant structural CamYyKña. EsluyLÚsCab:UlIsakarItTMrg;EdlmaneRcInbMputenAkúñg polysaccharide in plants. rukçCati. structural proteins : Proteins that are important for holding cells. RbÚetGIunTMrg; ³ RbUetGIunmansar³sMxan;kñúgkarRTRTg;ekasikanigPavrs; and organisms together, such as the proteins that make up the cell TaMgmUl dUcCaRbUetGIunEdlbgáPñasekasika sac;dMu srésBYr nigQam. membrane, muscles, tendons, and blood. style : The long, slender part of a pistil that supports the stigma. keksrjI ³ EpñkénkBa©úMeksrjImanragravEvgEdlRTRTg;sÞicma:t. subcutaneous (adj) : Under the skin. eRkamEs,k suberin : A waxy substance that occurs in cork cells and in the cells s‘uyEb‘rIn ³ sarFatuRkmYnEdlmanenAkñúgekasikaRsTab;Fn;Twk nigkñúg of underground plant parts; it consists of hydroxylated fatty acids ekasikaEpñkeRkamdIénrukçCati. vapÞúkGasIutxøaj; GIuRduksuIlEdlRtUv)an that are linked together in a P¢ab;KñakñúgrebobsaMjaMú. complex array. sublethal gene : A mutation which reduces the ability to survive. EsnBak;kNþalbgásøab; ³ muytasüúgEdlbnßylT§PaBrs;. Death before maturity occurs in less than 50 percent of the karsøab;muneBleBjv½yekItmaneLIgticCag 50 °énÉktþ³EdlpÞúk individuals carrying the gene. EsnenH. subliminal (adj) : A stimulus that is below the level that causes a kMritesÞIr ³ rMejacEdlsßitenAeRkamkMritEdleFVIeGaymancMelIytb. response. sublittoral zone : An area of shallow water from below the low tMbn;Ek,reqñr ³ tMbn;Twkrak;cab;BIeRkamRkitlMnacrhUtdl;mat;Twk. tide mark to the edge of the continental shelf. submetacentric chromosome : A chromosome with the centromere RkUmU:sUms‘ubemtasg;RTic ³ RkUmU:sUmmansg;RtUEmenARtg;kEnøg placed so that one arm of the chromosome is slightly longer than mYyEdleFVIeGayédRkUmU:sUmmçagEvgCagédmçageTotbnþic. the other.

subscript number : Number placed below and after the symbol cMnYnsnÞsSn_ ³ cMnYnEdldak;enABIeRkamnigeRkaynimµitsBaØarbs; for an element in a chemical formula indicating the number of FatumYykñúgrUbmnþKImI EdlbgðajBIcMnYnrbs;FatuenaHkñúgrUbmnþEdlman that element in the balanced tulüPaBsMrab;smasFatuenaH.]TahrN_³ snÞsSn_”2” kñúg H 20bBa¢ak;BI formula for the compound. e.g. the subscript “2” in H 20 indicates two GIuRdÚEsnBIrGatUm. ebIsinCacMnYnsnÞsSn_minRtÚv)anbgðajeTenaHeK hydrogen atoms. If a subscript number is not given, it is assumed snµtifavaesµInwgmYy. to be 1. subsidiary cells : Epidermal cells that are structurally distinct from ekasikabnÞab;bnSM ³ ekasikaeGBIEDm EdlmanTMrg;xusBIekasika other epidermal cells and associated with guard cells. eGBIEDmepSgeTot ehIysßitenACamYyekasikakarBar. subspecies : Regional groups within a species that are RbePTrg ³ RkumkñúgtMbn;énRbePTmYy EdlxusKñaCasMxan;BITMrg; srIr³ significantly different structurally, physiologically, or behaviorally, b¤¤Gakb,kiriya b:uEnþGacpøas;bþÚrEsnedaykarbgáat;Kña. yet are capable of exchanging genes by interbreeding. substitution : Mutation in which a single base has substituted for karCMnYs ³ muytasüúgEdl)asmYy)anCMnYseGay)asmYyeTotenAkñúg another in a DNA strand; a single codon is affected. See transition, Rcvak;GasIutedGuksIurIbUnuyekøGiuc. mankarb:HBal;dl;kUdugmYy. transversion. emIl transition, transversion . substrate : 1. The molecule on which an enzyme acts. The enzyme s‘ubRsþa ³ 1- m:UelKulEdlGg;sIummanGMeBIeTAelI. Gg;sIumkatalI catalyzes its conversion to product. 2. The solid on which a plant is bMElgrbs;vaeGayCaplitpl. 2- vtßúrwgEdlrukçCatiP¢ab;elI. attached. 3. The medium on which 3- mCÄdæanEdlPavrs;GaclUtlas;)an. an organism can grow. substrate-level phosphorylation : The transfer of a phosphate group pUsVrkmµkMrits‘ubRsþa ³ karbBa¢ÚnRkumpUsVatmYyBIs‘ub®sþa ¬dUcCa from a substrate, such as ADP ATP – phosphoenol pyruvic acid, to ADP, GasuItpUsVreGNulBIruyvic ¦eTA EdlbegáIt)anCa edayKµan thereby making ATP without O2 nigminBwgBak;RbB½n§dwknaMeGLic®tugeT. oxygen and independent of the electron transport system. succession : A process where plant and animal species of an area tMNKña ³ dMeNIrEdlRbePTrukçCati nigstVéntMbn;mYyrIkcMerIncab;BI®kum progress from initial colonisation to a climax population. Edlmkrs;enAdMbUgrhUtdl;b:UBuyLasüúgefr. successional community (sere) : An intermediate stage in shKmn_bnþKña ³ dMNak;kalkNþalkñúgtMNKña BIshKmn_mYyeTA succession. shKmn_mYyeTot. succinate (succinic acid) : A four-carbon organic acid that is GasIut s‘ucsIunic ³ GasuItsrIragÁmankabUnbYnEdlRtUv)aneFVI oxidized by the reduction of ubiquinone to ubiquinol in the GuksuItkmµedaykarbnßyG‘uyb‘ÍKINUneTAG‘uyb‘ÍKINulenAkñúgvKÁTIR)aMmYy sixth step of the Krebs cycle; the énvdþERkb. plitplénGuksuItkmµenHKWGasuItPuym:aric. product of this oxidation is fumaric acid. succinyl-CoA : An acetylated A four-carbon acid that is converted s‘ucsIunIl-kU ³ GasuItkabUnbYn GaesTILat EdlRtUv)anbþÚreTACa to succinic acid by losing its A acetyl-CoA group, thereby driving GasIuts‘ucsiuniceday)at;RkumGaesTIlkUGg;suIm rbs;va EdlbnÞab;mk the substrate-level phosphorylation )aneFVIeGaymanpUsVrkmµkMrits‘ub®sþaénm:UelKul ADP eGayeTACa ATP of one molecule of ADP to ATP in the fifth step of the Krebs cycle enAkñúgvKÁTIR)aMénvdþERkb.

succulent : A fleshy plant that stores water in its stems or leaves. TwkeRcIn ³ rukçCatisac;Rkas; EdlsþúkTwkenAxagkñúgedIm b¤søwkrbs;va. sucker : A sprout on the roots of some plants that forms a new plant. BnøkduHecjBIb¤s ³ BnøkelIrwsrbs;rukçCatimYycMnYnEdlnwg A form of vegetative propagation. køayCarukçCatifµImYy. TMrg;mYyénkarbnþBUCrbs;rukçCati. sucrase (invertase) : A type of enzyme that catalyzes the s‘uRkas ¬GaMgEvtas ¦ ³ Gg;suImmYyRbePTEdlkatalIskarbMEbk reversible breakdown of sucrose from starch by hydrolysis into free s‘uRkUsEdlGacRtLb;vij)anBIGamIdugedayeFVIGIuRdUlIseTACaRhVúctUses fructose and bound glucose; the rInigKøúykUs. KøúykUsenaHRtUv)anP¢ab;eTAnwgm:UelKuldwknaMehAfa glucose is bound to a carrier molecule called uridine G‘uyrIDInDIpUsVa (UDP) . diphosphate (UDP). sucrose : A disaccharide non- reducing sugar, produced in plants, s‘uRkUs ³ sárDIsak;karIt minGacbRgYmplitedayrukçCati consisting of fructose and glucose molecules joined together. EdlpSMeLIgedaykarP¢ab;KñaénRhVúctUs nigKøúykUs. sum law : The law that states that the probability of one or the other c,ab;srub ³ c,ab;EdlEcgfa RbU)ab‘ÍlIeténRBwtþikarN¾mYyrWmYykñúg of two separate events occurring is the sum of their individual cMeNamRBwtþikarN_BIrepSgKñaEdl)anekIteLIg KWCaplbUkén RbU)ab‘ÍlIet probabilities. énRBwtþikarN_TaMenaH. summer wood : See late wood. sac;eQIrdUvekþA ³ emIl late wood . supercoiled DNA : A form of ADN ADN DNA structure in which the helix is GgáÜjxøaMg ³ ragmYyénTMrg; EdlExSex©AGgáÜjelIxøÜnva coiled upon itself. Such structures ADN can exist in stable forms only when pÞal;. TMrg;rebobenHGac sßitenAefrEtenAeBlEdlcug minGacvil the ends of the DNA are not free to )an dUcCaenAkñúgm:UelKul ADN rgVg;biTCit. rotate, as in a closed circular DNA molecule. superfemale : See metafemale. s‘ubP½rhVIeml ³ emIl metafemale . superior ovary : An ovary located above the other flower parts on a GUEvelI ³ GUEvEdlzitenAelIbribu)öaénG½kSpáa. floral axis. supermale : See metamale. s‘ubP½reml ³ emIl metamale . suppressor mutation : A mutation that restores (completely or muytasüúgTb; ³ muytasüúgEdleFVIeGaydUcedImvij ¬TaMgRsugb¤mYy partially) the function lost by a previous mutation at another site. Epñk ¦ nUvmuxgarEdl)an)at;bg;edaymuytasüúgmunenARtg;kEnøgepSg. surface-area-to-volume ratio : The relationship between the smamaRtépÞelImaD ³ TMnak;TMngrvagRklaépÞrbs;vtßúmYyeTAnwgmaD surface area of an object and its volume. As objects increase in rbs;va. enAeBlvtßúenaHekInTMhM maDrbs;vanwgekIneLIgy:agelOnCag size, their volume increases more épÞrbs;va. vamanRbeyaCn_enAeBlBnül;BIépÞd¾FMrbs;kUnfg;sYtsMrab; rapidly than their surface area. Useful when explaining the large bNþÚr]sµ½n rWbBaðaEdlbNþalmkBIkMedAeLIgxøaMgcMeBaHstVFM². surface area of alveoli for gas exchange, or the problems of over heating in large animals. survival of the fittest : A major point of Darwin’s theory, that only karrs;enAsmRsbCageK ³ cMnucsMxan;énRTwsþIrbs;davIn Edlfaman the most fit survive to reproduce. EtPavrs;EdlbnSúaMeTAnwgbrisßanl¥CageKeTeTIbenArs;edIm,IbnþBUC)an.

suspension : Mixtures in which the solute particles are small enough kkrvilvl; ³ l,ayEdlPaKli¥ténFaturlaymanTMhMtUclµmEdl that gravitational force does not causes them to settle. kMlaMgTMnajminGaceFVIeGayvarg)an. suspension feeder : An animal that feeds on small particles stVsIukMeTckMTI ³ stVEdlciBa©wmCIviteday kMeTckMTIGENþtkñúgmCÄdæan suspended in the surrounding medium; this may be accomplished CMuvijEdlGacRbRBwtþeTAedaykareRcaH rWedayrebobepSg²eTot. by filtering or by other means. suspensor : A group of cells at the base of the embryo of many seed ekasikaruj ³ CaekasikamYyRkumenAKl;GMRb‘Íy:ugénrukçCatimanRKab; plants that expands and moves the embryo into the endosperm. PaKeRcIn EdlBRgIknigpøas;TIGMRb‘Íy:ugeTAkñúgGg;dUEs

sympatric : Having the same or overlapping geographic saM)a:RTic ³ Edlmanr)ayPUmisa®sþdUcKñab¤Can;Kña b:uEnþdac;BIKña distribution but separated by reproductive or biotic barriers. edayr)aMgbnþBUC rWr)aMgCIv³. sympatric speciation : Formation of a new species, entirely within kMNRbePTsaM)a:RTic ³ karbegááItRbePTfµImYyenAkñúgtMbn;PUmisaRsþ the geographical range of its parental form. énTMrg;em)arbs;vaTaMgRsug. sympatry : Occurrence of two or more species in the same area. saM)a:RTI ³ karekItmaneLIgénRbePTBIr rWeRcInenAkñúgtMbn;CamYyKña. symphysis : A joint between bones formed by a pad or disk of snøak;GDÆcl½t ³ snøak;q¥wgEdlbgáeLIgedayRTnab; rWfassrés fibrocartilage that allows a small degree of movement. q¥wgx©I EdlGaceGaymanclnatictUc. symplast : The interconnected living mass of an organism; the saM)øas ³ m:asrs;EdlmanGnþrTMnak;TMngKñaénPavrs;mYy. vaKWCa symplast is a continuous unit that is comprised of cells that are Éktat²Kña EdlbgáeLIgedayekasikaEdlP¢ab;Kñaeday)aøsµÚedsµa connected by plasmodesmata eBjsarBagÁkay. throughout the organism. symplastic : Movement of water and solutes through tissues by saM)aøsÞIc ³ clnarbs;Twk nigsarFaturlaytamCalika eday passing through interconnected protoplasts and their qøgkat;RbUtU)aøsEdlP¢ab;KñaeTAvijeTAmk nig)aøsµÚedsµarbs;va. plasmodesmata. symplesiomorphy : Character shared by a group of organisms saMePøsIuGUm½rhVI ³ lkçN³rYmKñaénPavrs;mYyRkum EdleKRbTH that is found in their common ancestor. eXIjkñúgbuBVrYmrbs;va. synapomorphy : When different species share the same modified sIuNab:Um½rhVI ³ RbePTxusKñamanlkçN³kMENERbdUcKña. characteristic. synapse : The place at which a nerve impulse passes from an axon sIuNab; ³ kEnøgEdlrMejacRbsaTqøgBIGak;sUnénekasikaRbsaTmYy of one nerve cell to a dendrite of another nerve cell. eTAdg;RDIténekasikaRbsaTmYyeTot. synapsis : The condition in which the two members of a pair of sIuNab;sIus ³ sßanPaBEdlRkUm:UsUmBIrrbs;RkUm:UsUmGUm:ULÚkmYyKUmk homologous chromosomes come to lie close to one another by their sßitenACitKña edayCMnab;rbs;vaenAtambeNþaykMpøicsIuNab;. attachment along a synaptonemal RkUsuIjGUevIekItmaneLIgkñugeBlsuINab;suIsenHEdr. complex; crossing over occurs during synapsis. synaptonemal complex : A complex of proteins that forms a kMepøcsIuNab; ³ kMpøicRbUetGIunEdlbegáItG½kSRbEvgRkUm:UsUmmYy chromosome –length axis linking homologous chromosomes sMrab;P¢ab;RkUm:UsUmGUm:ULÚkrvagLÚKusEsnEtmYy. between the same gene loci. syncytium : A mass of protoplasm containing many nuclei and not saMgsIusüÚm ³ m:asRbÚtU)øasmanéNVy:UeRcIn nigKaµncMENkeTA divided into cells. CaekasikaeRcIneT. syndactyly : Having two or more fingers or toes joined together. RmamCab;Kña ³ manRmamBIr b¤eRcInCab;Kña. syndrome : A group of symptoms with a single underlying cause. sheraKsBaaØ rWmUleraKsBaØa ³ eraKsBaØaeRcInénmUlehtumYy.

synergid : A type of cell that occurs next to the egg in an sIuEnsIut ³ ekasikamYyRbePTEdlmanenACits‘utkúñgfg;GMRb‘Íy:ug. embryo sac; sperm cells entering the embryo sac first pass through ekasikaEs

tagma : One of the divisions (head, thorax or abdomen) that the cMENkxøÜn ³ EpñkmYykñúgcMeNamEpñkTaMgLay ¬ k,al ®TUg b¤ eBaH ¦ body of arthropods is divided into. EdldgxøÜnrbs;GakRtUb:UtRtUv)anEck. taiga : A biome characterized by coniferous forests. éRBéthaÁ ³ tMbn;CIv³sMKal;edayéRBénrukçCatiBBYkRsl;. tall grass prairie : A type of grassland in the eastern United valesµAx

tautomeric shift : A chemical change in a molecule caused by the karbþÚrkEnøgtUtUEm ³ karpøas;bþÚrEpñkKImIkñúgmU:elKulmYyEdlbNþal movement of hydrogen atoms. In nucleic acids, tautomeric shifts in mkBIclnaGatUmGuIRdUEsn. kñúgGasuItnuyekøGuickarbþÚrkEnøgtUtUEmkñúg)as the bases can cause changes in GacbNþaleGaymankarpøas;bþÚr)asdéTeTotkñúgkMLúgeBlsV½ydMeLIgeTV other bases during replication and are a source of mutations. See base ehIyEdlCaRbPBénmuytasüúg. emIl base analogue . analogue. taxa : See taxon. ÉktacMENkfñak; ³ emIl taxon . taxis : A movement directly away from or toward a stimulus. taksIus ³ bMlas;TIecjBIb¤cUleTArkrMejac. taxol : A drug obtained from the Pacific Pacific yew, and also from a faksUl ³ fñaMmYyRbePTEdlykecjBIedImeQImüa:g eQµaH fungus that grows on the yew, with yew yew potential for treating certain forms ehIyk¾RtUv )anykecjBIpSit EdlduHelIedIm enHpgEdr. of cancer. fñaMenHmanRbsiT§iPaBkñúgkarBüa)alCMgWmharIk. taxon (pl. taxa) : Any scientifically recognized group of ÉktacMENkfñak; ³ RkumPavrs;EdlRtUv)ansÁal;tamn½yviTüasaRsþ. organisms. eg. species, genus, order etc. ]TahrN_ ³ RbePT BYk lMdab;.l. taxonomy : The science of classifying organisms. rebobcMENkfñak; ³ karsikSaGMBIcMEnkfñak;Pavrs;. T-cell : A type of lymphocyte T : activated by the thymus that ekasika RbePTLaMpUsIutRtUv)aneFIVeGayskmµedayTImus Edl attacks infected cells. RbyuT§RbqaMgekasikaEdlbgáCMgW. tegmen : The middle of the three layers surrounding the endosperm etkEmn ³ RsTab;kNþalénRsTab;TaMgbIBT½§CuMvijGg;dUEs

telophase II The second telophase II of meiosis; in telophase II, etLÚpas ³ vKÁetLÚpasTIBIrénemy:Us. kñúgvKÁenHRkUm:UsUmrla chromosomes uncoil and extend, the spindle apparatus disintegrates, ehIysn§wg RtyUgGaRkUm:aTicEbkCaEpñk² ehIyPñaséNVy:UfµImYy)an and a new nuclear envelope forms elcrUbrageLIgenACMuvijéNVy:UkUnfµITaMgbYn. around each of the four new daughter nuclei. telson : The posterior segment of the abdomen in some crustaceans. Etlsug ³ kg;eRkayeKéneBaHrbs;RKusþaesmYycMnYn. temperate deciduous forest : A biome characterized by plentiful éRBRCuHsøwkRbcaMqñaMéntMbn;RtCak;mFüm ³ tMbn;CIv³EdlsMKal;eday rain, dominated by deciduous hardwood trees and located in ePøogeRcIn RKbdNþb;edayedImeQIEdlRCuHsøwkRbcaMqñaMehIysßitenAkñúg areas with temperate . tMbn;GakasFatubgÁÜr. temperate phage : A ADN bacteriophage that can integrate its pasefr ³ )ak;etrIyU:pasEdlGacbBa©Úl rbs;vacUleTAkñúg DNA into the bacterial chromosome (see prophage) and RkUmU:sUm)ak;etrI ¬emIlRbUpas ¦ nigsßitenAefrCaeRcInCMnan;edaymin remain stable for many generations bNþaleGayEbkrWpÞúH)ak;etrIeT. without causing lysis. temperature : The hotness or coldness of something. Related to sItuNðPaB ³ PaBekþAb¤RtCak;rbs;GVImYyEdlTak;TgeTAnwg the average energy of motion of individual molecules or atoms. See famBlmFüménclnam:UelKulb¤GatUménrbs;enaH. Celsius scale, Kelvin scale. emIl Celcius scale, Kelvin scale . temperature-sensitive mutation : A mutation that produces a mutant muytasüúgrYsnwgsItuNðPaB ³ muytasüúgEdlbegáItepNUTIb phenotype at one temperature range and a wild-type phenotype at muytg;enAkMritsItuNðPaBmYy nigepNUTIbéRBenAkMritsItuNðPaBmYy another temperature range. epSgeTot. template : A model from which a ADN new structure can be made. This Bum

teratocarcinoma : Cancers that form in an embryo and are able to etr:atUkasIuNUm:a ³ mharIkEdlekIteLIgkñúgGMRb‘Íyu:g nigGacman develop into a wide variety of different cell types. lT§PaBlUtlas;eGayeTACaRbePTekasikaepSg²KñaCaeRcIn. terminal bud : An area of undeveloped tissues at the tip of a Bnøkcug ³ tMbn;CalikaminlUtlas;enAxagcugedIm. woody stem. terminalization : The movement of chiasmata toward the ends of cugkmµ ³ CaclnaküasµaEdleq

tetanus : A disease produced by toxins from the bacteria ettaNus ³ CMgWbgáedayCatiBulEdlbeBa©jeday)ak;etrIeQµaH Clostridium tetani , that causes Clostridium tetani sustained muscle contraction, EdleFVIeGaysac;dMuk®nþak;Cab;rhUtCaBiessfÁam especially of the jaw. Its common EdleRcInehAfa rwgfÁam. name is ‘lock-jaw’. tetrad : The group of four chromatids in a replicated set of etRtat ³ RkumRkUma:TItbYnenAkñúgRkumRkUm:UsUmGUm:ULÚkEdlsV½ydMeLIgeTV. homologous chromosomes. tetrad analysis : Method for the analysis of gene linkage and karviPaKetRtat ³ viFIsMrab;viPaKCMnab; nigbnSMfµIénEsnedaykareRbI recombination using the four haploid cells produced in a single ekasikaGabøÚGuItbYnEdlRtUv)anbegáItkñúgcMENkemyU:smþg. meiotic division. tetrad scar : A scar on a primitive spore at the place where three other snøaketRtat ³ snøakelIs,:edImenAkEnøgEdls,:bIepSgeTotRtUv)an spores are attached, all four having developed after meiosis; P¢ab; ehIys,:TaMgbYnenH)anlUtlas;bnÞab;BIemy:Us. karduHBnøkRbRBwtþ germination takes place near the eTAenACitsnøakenH. scar. tetrahedron : Symmetrical geometric shape with four vertices etRtaEGt ³ TMrg;FrNImaRtsIuemRTICamYynwgExSQrbYnnigmanmMu and equal bond angles. énkarcgsm<½n§esIµKña. tetraparental mouse : A mouse produced from an embryo that kNþúrEdlekItBIem)abYn ³ kNþúrEdlekItecjBIGMRb‘Íyu:gmYyEdl formed when two separate blastulas joined together. ekIteLIgenAeBl)aøsTuyLaepSgKñaBIr)anP¢ab;Kña. tetraploid : A cell with four sets of n chromosomes. etRtabøÚGIut ³ ekasikaEdlmanRkUm:UsUm4 . tetrapoda : Four-legged vertebrates; the group includes ctu)aT ³ stVq¥wgkgEdlmaneCIgbYn EdlrYmmanGMbUrkEgáb lµÚn amphibians, reptiles, birds, and mammals. bkSI nigfnikstV. thalamus : A region of the brain that relays and screens sensory taLamus ³ EpñkmYyrbs;xYrk,alEdleRCIserIsnigbBa¢ÚnbnþrMejac stimuli. viBaØaN. thallus : The body of a nonvascular plant. tal; ³ sarBagÁkayrukçCatiKµansrésnaM. thecodont teeth : Teeth set in bony sockets in the jaw. eFµj etkUdug ³ eFµjEdlduHcUleTAkñúgrn§qw¥gfÁam. theory : A plausible, scientifically acceptable RTwsþI ³ eKalKMnitviTüasaRsþEdlGacTTYlyk)annigKYreGayeCO)an generalization supported by several hypotheses and a lot of nigRtUv)anKaMRTedaysmµtikmµCaeRcIn nigmanPsþútagEdl)anmkBIkar experimental evidence. BiesaFn_CaeRcIn. therapsid : Extinct Mesozoic mammal-like reptile, from which etra:bsIut ³ lµÚndUcfnikstVEdlvinasputBUCenAs½kemsUsUGuic nigEdl true mammals evolved. vivtþeTACafnikstVBit. thermophilic (adj) : capable of living in conditions over 45 oC. rs;enAkñúgsItuNðPaBx

thioester : Fuctional group derived from an acid and a thiol. tüÚeGEsÞ ³ RkumbgÁúMnaTIEdl)anmkBIGasIutnigtüÚl ³ O O

R1 C S R2 R1 C S R2 thiol : Sulfur analog of an alcohol in which oxygen is replaced by tüÚl ³ s

thyroxine : A hormone secreted by the thyroid gland that controls the TIr:UsIun ³ GrmU:nbeBa©jedayRkeBjTIrU:GIut EdlRtYtBinitüGRta body’s metabolic rate. emtabUlIlkñúgsarBagÁkay. tibia : One of the two parallel bones in the hind limb of tetrapods. q¥wgsµgeCIg ³ q¥wgmYykñúgcMeNamq¥wgRsbKñaBIrénGvyv³eRkayrbs;stV See pentadactyl limb, and p. 321 eCIgbYn. sUmemIl pentadactyl limb nigemIlTMBr½ 321 . tibiotarsus : Bone formed by fusion of the tibia and proximal q¥wgsµg-keCIg ³ q¥wgEdlbgáeLIgedaykarrlaycUlKñaénq¥wg sµgeCIg tarsal elements in birds and some dinosaurs. See tarsometatarsus. nigq¥wgkeCIg cMeBaHbkSI nigdayNUs½rmYycMnYn. emIl tarsometatarsus . tiller : A young side stem in grasses which grows from the base edImBnøk ³ edImx©IEdlduHecjBI)aténtYedImrbs;rukçCatiRkamIen. of the main stem. timberline : The point on a mountain slope above which trees RBMx½NÐéRBduH ³ cMnucsßitenAelICMralPñM EdlenAxagelIRBMx½NÐenaH cannot grow. edImeQIminGacduH)an. tinea : Fungal infection of the skin. eg. ‘ringworm’. ERsgepH ³ CMgWesIEs,kmüa:gEdlbgáedaypSit. ]TahrN_ ³ ERsg. tissue : A group of similar cells that work together to perform a Calika ³ RkumekasikadUcKñaEdleFVIkarrYmKñaedIm,IdMeNIrkarmuxgarmYy. function. tissue culture : A technique for growing pieces of tissue (plant or karbNþúHCalika ³ bec©keTskñúgkarbNþúHbMEnkCalika ¬rukçCati rWstV ¦ animal) in a medium after their removal from the organism. The kúñgmCÄdæanmYybnÞab;BI)anykecjBIPavrs;. mCÄdæanciBa©wmenH medium is sterile and usually KµanemeraK ehIyeRcInEtmanG½rm:UnnigsarFatulUtlas;. contains hormones and growth substances. tissue fluid : A liquid similar to plasma that escapes from the TwkCalika ³ sarFatudUc)aøsµaEdlecjBIsrésbþÚreTAsßitenACMuvij capillaries and bathes the body cells. ekasika. titration : Process in which a measured volume of a known GRtakmµ ³ dMeNIrEdlmaDvas;rYcénsUluysüúgdwgkMhab;RbtikmµCamYy solution is reacted with a solution of unknown concentration to sUluysüúgmindwgkMhab;edIm,IkMnt;kMhab;rbs;va. cMnucEdlsUluysüúg determine its concentration. The mindwgRtÚv)aneRbIGs; CaTUeTARtUv)ankMNt;edayFatuKImIcg¥úlBN’Edl point at which the unknown is completely consumed is usually pøas;bþÚrBN’enAcMNucbBa©b;. identified by a chemical indicator that changes color at the “end point.” T : The temperature at which a m T population of double-stranded m ¬sItuNðPaBrlay¦ ³ sItuNðPaBEdlmU:elKulGasuItnuyekøGiuc nucleic acid molecules is half-dissociated into single strands. Rcvak;eTVRtUv)anpþac;ecjBIKñaBak;kNþaleTACaRcvak;eTal. sItuNðPaB This called the melting temperature enHehAfasItuNðPaBrlaysMrab;RbePTénGasuItnuyekøGuicenaH. for that species of nucleic acid. tolerance : A condition in which more of a drug becomes necessary PaBTTYl ³ sßanPaBEdlRtUvkarfñaMkan;EteRcInedIm,IeGay)anpl to produce the same effect that a small amount once produced. dUcKñanwgplénbrimaNfñaMticenAeBlplitBIdMbUg.

tonoplast : The membrane that surrounds a vacuole; also called a tUNU)aøs ³ PñasEdlB½T§CMuvijv:aKuyGUl. eKehAvafaPñasv:aKuyGUl vacuolar membrane. pgEdr. tooth : Hard structure in the mouth of vertebrates used for biting, eFµj ³ TMrg;rwgenAkñúgmat;rbs;stVq¥wgkg EdleRbIsMrab;xaM Ehknigkin tearing and crushing food. Consists of a very hard external mineral kMeTcGahar. vabgáeLIgedayRsTab;rwgenABIeRkA ehAfakacaeFµj layer called enamel, over a bone- eRsabBIelIRsTab;EdlmanlkçN³dUcCaq¥wg ehAfaPøúkeFµj EdlrMuB½T§ like layer called dentin, which surrounds a central cavity EpñkkNaþl mansrésbþÚrQam nigcugsrésRbsaT. containing blood capillaries and nerve endings. topoisomerase : A type of enzyme ADN that relieves the kinks in DNA that tUb:UGIusUEmr:as ³ Gg;suImmYyRbePTEdlBnøakMNYckñúg would otherwise block the movement of replication forks; EdlnwgGacraMgsÞHclnaCMBamsV½ytMelIgeTV. tUb:UGIusUEmr:aseFVIkar topoisomerases work by breaking bMEbkRcvak;mçag rWTaMgsgxagedIm,IeGayExSenaHrla edaybgVilCMuvij one or both strands, thereby allowing the strands to uncoil by Kña. bnÞab;BIBnøaehIyRcvak;enaHRtUv)anP¢ab;KñavijedayGg;suIm swiveling around one another; after uncoiling, the strands are also tUb:UGIusUEmr:as. linked back together by topoisomerases. torr : Unit of pressure equal to the pressure exerted by a standard T½r ³ ÉktasMBaFesIµnwgsMBaFkñúgbMBg;sþg;daén)ar:tkMBs;mYy column of mercury 1.00 mm in height. mIlIEm:Rt. tortoise : A land-living turtle. GeNþIk ³ GeNþIkEdlrs;enAelIeKak. totipotent : Refers to the idea that every cell has the same genes and tUTIb:Utg; ³ KMnitEdlfaRKb;ekasikaTaMgGs;suT§EtmanEsndUc²Kña therefore the same genetic potential to make all cells and other cell dUecñHvak¾manskþanuBlPaBesenTicdUcKñakñúgkarbegáItekasikaTaMgGs; types. nigekasikaepSg²eTot. toxic waste : Any poisonous or carcinogenic substance. sMNl;Bul ³ sarFatuBul b¤sarFatuEdlbgáeGaymanCMgWmharIk. toxin : Any substance that interferes with the normal CatiBul ³ sarFatuEdlraMgsÞHdMenIrkarFmµtarbs;ekasika. functioning of body cells. trace elements : See micronutrients micronutrients. sarFatutictYc ³ emIl . tracer : Radioactive isotope used to follow the passage of the eRtss½r ³ GIusUtUbviTüúskmµEdleRbIedIm,ItamdandMeNIrénFatu element of molecule in question 14 C through a biological or physical rbs;m:UelKulkMBugsikSaqøgkat;RbBn½§CIv³saRsþb¤rUb. ]TahrN_ . system. eg. 14 C trachea : 1. The windpipe, a tube leading from the mouth to the bMBg;xül; 1- bMBg;BImat;dl;TgsYt. 2- bMBg;EdlebIkcMhecjeTA bronchi. 2. A tube that opens to the outside for gas exchange in insects xageRkAsMrab;bþÚr]sµ½n cMeBaHstVl¥itnigBIgBag. and spiders. tracheid : A long, thick-walled hollow xylem cell. RtaekGIut ³ ekasikasIuELmEdlRbehagkñúg nigmanPñasRkas;nig manragRTEvg. tracheophytes : Plants having vascular tissue. RtaekGUPIt ³ rukçCatiEdlmanCalikasrésnaM.

trailer sequence : An extra ADN amount of non-coding DNA that is tMNlMdab;elIs ³ cMnYnelIsén mincMlgRkmEdlRtUv)ancMlg transcribed into RNA beyond the ARN end of the gene. eTACa enAxagcugEsn. trait : Any phenotypic variation of a particular inherited character. lkçN ³³³ ³ bMErbMrYlepNUTIbénlkçN³tMnBUCCak;lak;mYy. tranquilizer : A drug used to reduce anxiety. fñaMrMgab;GarmµN_ ³ fñaMeRbIedIm,Ibnßykarfb;GarmµN_. trans- : Prefix used to designate two similar groups on opposite Rtg;s_;- ³ buBVbTeRbIedIm,IbBa¢ak;RkúmBIRkumRsedog²KñaBIrsßitenARbQm sides of a molecule. Kñaénm:UelKulmYy. trans configuration : The arrangement of two mutant sites rUbsNðanRtg;s_ ³ kartMerobkEnøgmuytg;BIrEdlTItaMgrbs;vaRtUv whose positions are reversed on homologous chromosomes. )anRtlb;elIRkUmU:sUmGUmU:LÚk. vapÞúyeTAnwgkartMerobsuIsEdlmuytg; Contrasts with a cis arrangement, manTItaMgEtmYyelIRkUmU:sUmGUmU:LÚk. where they are located at the same positions on homologous chromosomes. transamination : Reaction that transfers amino groups from amino karepÞrGamIn ³ RbtikmµEdlepÞrRkúmGamInBIGasIutGamIeneTAeGay acids to a-ketoglutarate to yield keto acids and glutamate. estUKøúytara:tedIm,IIeGayCaestUGasIutnigKøúytama:t. transcription : The process of ADN ARN copying the DNA code to form a karcMlgRkm ³ dMeNIrcMlgRkm eGayeTACaRcvak; strand of RNA which can be ARN ARN ARN transfer RNA, messenger RNA or EdlGac Ca dwknaM naMsar b¤ rIbUsUm. ribosomal RNA. transdetermination : Change in final form of a cell or group of bMlas;bþÚrcugeRkay ³ karpøas;bþÚrTMrg;cugbBa©b;énekasikamYy b¤ cells after development. RkumekasikabnÞab;BIkarlUtlas;. transduction : A process in which a bacteriophage injects a portion of )atuPUtdwkCBa¢Ún ³ dMeNIrEdl)ak;etrIy:Upascak;bBa©ÚlEpñkmYyén one bacterial chromosome into another bacterium. RkUm:UsUmrbs;)ak;etrImYyeTAkñúg)ak;etrImYyeTot. transect, line : A straight line across a habitat, where samples of ExSkat;TTwg ³ ExSRtg;kat;kEnøgrs;enAmYyEdlCakEnøgPavrs; organisms are studied to describe changes in the distribution of KMrURtUv)ansikSaedIm,IBN’naBIkarpøas;bþÚrkñúgr)ayPavrs;. organisms. transfer RNA (tRNA) : ARN Ribonucleic acid molecules that dwknaM ³ m:UelKulGasIutrIbUnuyekøGiuc EdldwknaMGasIutGamIen transfer the correct amino acids into the protein that is being RtwmRtÚvedIm,IbegáItRbÚetGIunEdlkMBugEtRtÚv)ansMeyaKedayrIbUsUm. synthesized by ribosomes. transformation : A process by which some bacteria can absorb )atuPUtbMElg ³ dMeNIrEdl)ak;etrImYycMnYnGacRsUbbBa©Úl and incorporate DNA from their ADN surroundings. BImCÄdæanCMuvijrbs;va. transgenic : Refers to cells or organisms that contain genes that bnSMEsn ³ ekasikab¤Pavrs;EdlpÞúkEsnEdlRtUv)anbBa©ÚleTAkñúgxøÜn were inserted into them from other organisms by genetic engineering. vaBIPavrs;epSgeTotedayvisVkmµesenTic. transition : A mutation in which one purine is replaced by another, bMlas;bþÚrdUc ³ muytasüúgEdlBuyrInmYyRtUv)anCMnYseday or one pyrimidine is replaced by another. BuyrInmYyeTot b¤BIrImIDInmYyRtUv)anCMnUsedayBIrImIDInmYyeTot.

translation : A synonym for protein synthesis. The process of karbkERbRkm b¤bMNkERbRkm ³ n½ydUcKñaCamYynwgBaküsMeyaK assembling amino acids into proteins at the ribosomes according RbÚetGIun. dMeNIrP¢ab;GasIutGamIeneGayeTACaRbUetGIunenARtg;rIbUsUmeTA to the instructions carried by tamBt’manenAelI ARN naMsar. messenger RNA. translocation : 1. A mutation in E. which a chromosomal piece bMlas;Ggát;RkUm:UsUm ³ muytasüúgEdlEpñkmYyrbs;RkUm:UsUm becomes attached to another chromosome. 2. The transport of mYy)anP¢ab;eTAnwgRkUm:UsUmmYyepSgeTot. food through the phloem of a 2-dMNwknaM ³ kardwknaMGahartampøÚEGmrbs;rukçCatisrésnaM. vascular plant. transmission electron microscopy TEM (TEM) : Microscopy that focuses ³ mIRkUTsSn_EdleRbIkaMrsµIeGLicRtugqøgkat;xñat;esþIgKMrUmYyedIm,I an electron beam through the thin eFVIkarsikSaBITMrg;kúñgrbs;va. section of a specimen to study its internal structure. transmutation : Process of conversion of one element to an- Rtg;s_muytasüúg ³ lMnaMénbMElgBIFatumYyeTAFatumYyeTot other by radioactive decay or nuclear bombardment. tamkarbMEbkviTüúskmµb¤edaykar)aj;éNVy:U. transpiration : The loss of water from the leaves of a plant through rMPaycMhayTwk ³ kar)at;bg;TwkBIsøwkrukçCati tamsþÚm:at nig the stomates and lenticels by evaporation. Lg;TIesl edayrMhYt. transpiration-cohesion theory : The idea that water is pulled up the RTwsþI-P¢ab;rMPaycMhayTwk ³ KMnitEdlfa TwkRtUv)anbWteLIgtam xylem in a stem as a result of transpiration from the leaves and suIELmkñúgedImrukçCatiedaysarman rMPaycMhayTwktamsøwk nigkMlaMg the cohesion of water molecules. TMnajrvagm:UelKulTwk. transport protein : A protein embedded in the plasma membrane RbÚetGIundwknaM ³ RbUetGIunkñúgPñasekasika EdlCYydwknaMsarFatu that aids the entry of a specific substance into the cell. yfaRbePTcUleTAkñúgekasika. transposable element : A ADN fragment of DNA that can Fatupøas;TI)an ³ Ggát; EdlGacbMlas;TIeTAkEnøgdéTeTotkñúg translocate to other sites in the genome. esNUm. transversion : A mutation in which a purine is replaced by a bMlas;bþÚrbRBaa©s ³ muytasüúgEdlkúñgenaHBuyrInmYyRtUv)anCMnYs pyrimidine, or a pyrimidine is replaced by a purine. edayBIrImIDIn b¤BIrImIDInmYyRtUv)anCMnYsedayBuyrIn. triacylglycerols : See triglyceride. RTIGasIulKøIesr:ul ³ sUmemIl triglyceride . tricarboxylic acid (TCA) cycle : Cyclic pathway that oxidizes vdþGasIutRTIkabuksIulic ³ clnkarCavdþEdleFIVGuksIutkmµGaesTIl- acetyl-CoA to C0 2, yielding A reduced and phosphorylated coen- kUGg;sIum- eGayeTACa]sµ½nkabUnic edaypþl;kUGg;sIumrgerdukmµ zymes as the other products. See nigpUsVÚkmµ dUcCaplitpldéTeTot. emIl Krebs cycle . Krebs cycle. triceps : In tetrapods, a muscle in the upper arm that moves the lower sac;dMuvavbI ³ cMeBaHstVeCIgbYn Casac;dMuedImédEdleFVIeGaykMPYnéd arm. It has three ‘heads’ or points of connection to bone and forms an manclna. vamank,albI rWk¾cMnucbIEdl P¢ab;eTAnwgq¥wg nigbegáIt)anCaKU antagonistic pair with the biceps. bdibkçCamYysac;dMuvavBIr. emIlTMBr½ 326 . See p. 326. trichoblast : Plant epidermal cell that develops into a root hair. RTIkU)aøs ³ ekasikaeGBIEDmrukçCatiEdllUtlas;eTACaeramCBa¢k;.

trichocyst : A flask-shaped cell under the pellicle of a paramecium ekasikaeram ³ ekasikaragdUcdbsßitenAxageRkamPñasrbs;)a:ra:emsuI and other protists that can release a threadlike structure for defense or nigRbUTIsþepSgeTot EdlGacbeBa©jTMrg;dUcsrésGMe)aH sMrab;karBar for food-getting. b¤cab;Gahar. trichogyne : A receptive, slender outgrowth for spermatia or similar RTIkUsIun ³ EpñkduHecjmanragrav sMrab;Es sk; b¤ Rska. tricuspid valve : A valve in the heart between the right atrium and RbwsftelI-eRkamsþaM ³ RbwskñúgebHdUgEdlsßitenAcenøaHftelIsaþM right ventricle. nigfteRkamsþaM. triglyceride : An organic molecule made of glycerol bonded to three RTIKøIesrIt ³ m:UelKulsrIragÁEdlbgáeLIgedayKøIesr:ul P¢ab;eTAnwg fatty acid molecules that are also called fats and oils, used for GasIutxøaj;bIm:UelKul EdlehAfaxøaj;b¤eRbgpgEdr EdleRbIsMrab; storage of energy in plants and sþúkfamBlenAkñúgrukçCatinigstV. animals. triiodothyronine : A hormone produced by the thyroid gland that RTIGIuy:UdUTIr:UnIn ³ Grm:UnplitedayRkeBjTIr:UGIutEdlbegáInel,On speeds up the metabolic rate; similar to thyroxine but more emtabUlIs. vaRbhak;RbEhlTIr:uksIunEdr b:uEnþxøaMgCag. potent. triplet : Refers to a sequence of three nucleotides that together RtIFatu ³ sMedAeTAelItMNlMdab;nuyekøGUTItbIEdlrYmKñabegáIt)anCa make a codon. kUdugmYy. triploblastic : Exhibiting three distinct tissue layers during RsTab;bI ³ EdlmanRsTab;CalikabIRsTab;kñúgdMNak;lUtlas; embryonic development. énGMRb‘Íy:ug. triploidy : The condition in which a cell or organism has three haploid RTIbøÚGuIDI ³ lkç½x½NÐEdlekasikab¤Pavrs;mYymancMnYnRkUmU:sUm sets of chromosomes. GabøÚGuItbI. trisomy : Having an extra Down’s syndrome, Edwards chromosome. See Down’s RTIsUmI ³ manRkUm:UsUmelIsmYy. emIl syndrome, Edwards syndrome syndrome and Patau syndrome and Patau syndrome. . triterpene : A compound that consists of six isoprene units linked RTIETEBn ³ smasFatuEdlpÞúkÉktaGIusUERbnR)aMmYyP¢ab;Kña. together; sterols, such as beta-sitosterol beta-sitosterol, are triterpenes. esþr:uldUcCa KWCaRTIETEBn. tritium ( 3H) : A radioactive isotope of hydrogen, with a RTIsüÚm ³ GuIsUtUbviTüúskmµrbs;GuIRdUEsn EdlBak;kNþalCIvitvaKw half-life of 12.46 years, often used as a label on tracer molecules. 12/46qñaM Cajwkjab;RtUv)aneRbICapøakelImU:elKultamdan. tRNA : See transfer RNA. tRNA ³ emIl transfer RNA . trochophore : A larval stage in mollusks and some annelids. RtÚkUpr ³ dMNak;kUnjas;rbs;sib,IstV nigdgáÚvxøÜnkg;mYycMnYn. troglodyte : Organism that lives in caves. RtUkøÚDIt ³ Pavrs;Edlrs;enAkñúgrUgPñM. trophic : Relating to feeding and nutrition. pþl;Gahar ³ EdlTak;TgeTAnwgkarpþl;cMNIGahar nigsarFatuciBa©wm. trophic level : A step in the flow of energy through an ecosystem. dMNak;Gahar ³ dMNak;énkarbBa¢ÚnfamBltamzanRbB½n§.

trophoblast : A layer of cells in the blastocyst that will develop into RtÚpU)aøs ³ ekasikamYyRsTab;rbs;)aøsþÚsIusEdlnwglUtlas;eTACa the embryonic membranes. PñasGMRb‘Íy:ug. tropic hormone : A hormone that influences the activity of a specific Grm:UnyfaRbePT ³ Grm:UnEdlman\T§iBleTAelIskmµPaBrbs; gland. RkeBjyfaRbePT. tropical rain forest : A biome characterized by heavy rainfall, éRBtMbn;RtUBic ³ tMbn;CIv³EdlsMKal;edayePøogy:agxøaMg sItuNðPaB constant warm temperatures and dense growth of many plant ekþACaRbcaM nigmankarlUtlas;rukçCatiCaeRcInRbePTy:agRkas;. species. tropism : A directional growth response of a plant to an TMenarTis ³ tMNblUtlas;rbs;rukçCatieTAnwgrMejacrbs;brisßan Edl environmental stimulus caused by auxin unequal distribution of the plant bNþalmkBIr)ayminesµIKñaénGrm:UnlUtlas;rbs;rukçCati ¬ ¦. growth hormone, auxin. See sUmemIl phototropism, geotropism, thigmotropism, chemotropism . photo-tropism, geotropism, thigmo-tropism, chemotropism. tropomyosin : A molecule found in thin filaments of muscle that RtUb:UmIy:UsIun ³ m:UelKulenAkñúgsésqµarénsac;dMu EdlCYytMrUvenA helps to regulate when muscle cells contract by blocking the interaction eBlekasikasac;dMukRnþak; edaybg¥ak;GnþrGMeBIrvagsrésnigmIyUsuIn. between the filaments and myosin. troponin : A molecule found in thin filaments of muscle that helps RtUb:UnIn ³ m:UelKulenAkñúgsrésqµar²énsac;dMu EdlCYytMrUvenAeBl to regulate when muscle cells contract by interacting with ekasikasac;dMukRnþak; edaymanGnþrGMeBICamYyRtUb:UmIy:UsuIn ehIyeFVI tropomyosin and thus allowing eGaymankark®nþak;sac;dMu. muscle contraction. true-breeding : Refers to purebred strains for a given trait, which karbgáat;Bit ³ sMedAeTAelIBUCbgáat;suT§ sMrab;lkçN³mYy means that the gene for that trait is homozygous. Edlmann½yfaEsnsMrab;lkçN³enaHKWGUm:UsIukUt. tube cell : The cell in the pollen grains of seed plants that develops ekasikabMBg; ³ ekasikaenAkñúgRKab;lMGgénrukçCatimanRKab; Edlnwg into the pollen tube. lUtlas;eTACabMBg;lMGg. tube feet : A series of small suction disks used for locomotion eCIgbMBg; ³ RbePTeCIgragdUcfasbWttUc²mYyes‘rIIsMrab;bMlas;TI nig and food-getting in echinoderms. cab;GaharéneGKINUEDm. tube nucleus : One of two haploid nuclei in a pollen grain. éNVy:UbMBg; ³ éNVy:UmYykñúgcMenaméNVy:UGabøÚGIutBIrenAkñúgRKab;lMGg. tuber : A swollen underground stem or root containing starch. eg. emIm ³ edImeRkamdIrage)a:g. ]-emImdMLÚg)araMg. potato is a stem tuber, ginseng is a root tuber. tuberculosis : An infectious mycobacterium disease caused by a bacterium CMgWrebg ³ CMgWqøgEdlbNþalmkBI)ak;etrIeQaµH (mycobacterium tuberculosis ). It is tuberculosis usually transmitted by inhaling tiny . CaTUeTAvaRtUv)ancMlgedaykardkdegðImcUlnUvdMNk;Twk drops of saliva from an infected mat;tUc²BIGñkCMgW. eraKsBaØarYmmankark¥k EdlbNþalmkBIkarrlak person. Symptoms include coughing caused by irritation and Rkhay nigkarekIneLIgnUvesøsµenAkñúgsYt. accumulation of mucus in the lungs. tubulin : S ee alpha-tubulin and alpha-tubulin beta-tubulin beta-tubulin. TUb‘UlIn ³ emIl nig .

tumour : A swelling or growth caused by disease. dMuBk ³ karehIm b¤karduHrIkFMEdlbNþalmkBICMgW. tundra : Terrestrial habitat zone, between taiga in south and polar TunRda ³ tMbn;rs;enAelIdIEdlsßitenAcenøaHéRBéthÁaPaKxagt,Úg nig region in north; characterized by absence of trees, short growing tMbn;bU:lPaKxageCIg EdlsMKal;edayGvtþmanénedImeQI manrdYvlUt- season, and mostly frozen soil las;xøI nigmanFøak;TwkkkesÞIrRKb;TIkEnøgkñúgry³eBlEvgkñúgmYyqñaM². during much of the year. tunica-corpus : The organization of the shoot apex of most GgÁeRsam ³ rUbpÁúMBnøkxagkñúgrbs;rukçCatiGg;süÚEs

ulna : One of the two parallel bones in the forelimb of tetrapods. q¥wgFMkMPYnéd ³ q¥wgmYykñúgcMeNamq¥wgRsbKñaBIr énGvyv³muxrbs; See pentadactyl limb and p.321. stVeCIg4. sUmemIl pentadactyl limb nigemIlTMBr½ 321 . ultracentrifuge : A high-speed centrifuge that is capable of ]bkrN_RbTajecjG‘ulRta ³ Rbdab;RbTajecjelOnEdlGacvil spinning at more than 100,000 Svedburg units revolutions per minute. See )anrhUtdl;Cag 100>000 CMukñúg1naTI. emIl . Svedburg units. ultrasound : A technique using sound waves to locate the position sMelgG‘ulRta ³ bec©keTseRbIrlksMelg edIm,IrkTItaMgrbs;KP’ of a fetus in the uterus. kñúgs,Ún. ultraviolet (U.V.) : A type of electromagnetic radiation with sVayG‘ulRta ³ RbePTmYyénrsµIeGLicRtUma:ej:Tic EdlmanRbEvgrlk wavelengths from 18,000 nm to 18 000 nm 33 000 nm 33,000 nm. It is a powerful BI eTA . vaKWCamuytaEsnEdlman\T§iBlxøaMg mutagen and is harmful to the nigmaneRKaHfñak;cMeBaHerTInnigEs,krbs;mnusS. human retina and skin. umbilical cord : A long cord that connects the fetus to the placenta Tgsuk ³ BYrEvgEdlP¢ab;KP’eTAsuk EdlbgáeLIgedaysrésGakETr consisting of two arteries and one vein. BIr nigsrésEv:nmYy. understory : A layer of smaller trees and plants in a deciduous rukçCatiRbcaMqñaMeRkaméRBdMbUl ³ RsTab;rukçCatitUc²CagkñúgéRBRCuHsøwk forest between the groundcover and the canopy. RbcaMqñaM enAcenøaHrukçCatiEk,rdI nigéRBdMbUl ¬rbs;rukçCatix

unsaturated : A term used to describe an organic molecule that minEq¥t ³ BaküeRbIedIm,IBN’nam:UelKulsrIragÁEdlmansm<½n§BIrb¤bICan; has double or triple bonds and therefore fewer than the maximum dUecñHticCagcMnYnGtibrmaénGatUmGIuRdUEsnEdlP¢ab;eTAnwgGatUmkabUn number of hydrogen atoms bonded nimYy². to each carbon atom. unsaturated fatty acids Fatty acid that has one or more C-C double GasIutxøaj;minEq¥t ³ GasIutxøaj;Edlmansm<½n§BIrCan;mYy bonds. b¤eRcInrvagkabUnnigkabUn. unwinding proteins : Nuclear ADN proteins that unwind the DNA RbÚetGIunBnøa ³ RbUetGuInéNVy:UEdlBnøaregVleTV xagmux helix ahead of the replicating fork ADN during DNA replication. CMBamsV½ytMelIgeTVkñúgkMLúgeBlsV½ytMelIgeTV . up promoter : A promoter sequence that increases the rate of Gab;RbUm:UT½r ³ tMNlMdab;RbUmU:Tr½EdlbegáInGRtaénkarcab;epþIm transcription initiation. It is also known as strong promoter, and is cMlgRkm. vaRtUv)aneKsÁal;faCaRbUmU:Tr½xøaMg nigPaKeRcInCamuytg;. often a mutant. uracil : A nitrogen base C H N 0 (pyrimidine) with the formula G‘uyra:sIul ³ )asGasUt ¬BIrImIDIn ¦manrUbmnþ 4 4 2 2 EdlmanEt C4H4N202 found only in RNA. ARN Always pairs with adenine. enAkñúg . vaEtgEtP¢ab;KU)asCamYyGaednIn. urea : A nitrogenous waste produced from the digestion of G‘uyer ³ sMNl;GasUt)anmkBIkarrMlayRbUetGIun EdlCasmasPaK protein, the main component of urine. d¾sMxan;rbs;Twkenam. urea cycle : Pathway that converts excess metabolic ammonia to vdþG‘uyer ³ lMnaMbMElgGam:Ujak;elIskñúgemtabUlIseGayeTACaG‘uyer relatively nontoxic urea which is then filtered out by the kidneys and minBul EdlbnÞab;mkRtUv)aneRcaHedaytMrgenam rYcbeBa©jecal. excreted. ureotelic : Excreting nitrogenous wastes primarily as urea. G‘uyerGUetlIc ³ karbeBa©jecalsMNl;GasUteGayeTACaG‘uyer. ureter : A tube that carries urine from a kidney to the bladder or bMBg;enam ³ bMBg;EdldwknaMTwkenamBItMrgenameTAe)aøkenamb¤køÚGak;. cloaca. urethra : The tube from the urinary bladder to the exterior in bgðÜrenam ³ bMBg;ecjBIe)øakenameTAxageRkA cMeBaHePTTaMgBIr. both sexes. uricotelic : Excreting nitrogenous wastes primarily as uric acid and G‘uyrIkUetlIc ³ karbeBa©jecalsMNl;GasUt eGayeTaCa its salts. GasIutG‘uyric nigGMbilrbs;va. uridine diphosphate (UDP) : A uracil-containing nucleotide that G‘uyrIDInDIpUsVat ³ nuyekøGUTItpÞúkG‘uyr:asuIl EdledIrtYCaGñkdwknaM acts as a carrier molecule for UDP- glucose and similar mono- mU:elKulKøúykUs nigm:UNUsakarItRsedogKña. kuMepøc sárk¾Ca saccharides; the UDP-sugar smasFatukNþalsMrab;karbMElgeTAvijeTAmkBIm:UNUsakarItmYy complex is also an intermediate compound for the interconversion eTAm:UNUsakarItmYyeTotpgEdr ¬]> BIKøúykUseTAkaLak;tUs ¦. of one monosaccharide to another (e.g., glucose to galactose). urinary bladder : A hollow organ that stores urine. e)aøkenam ³ srIragÁRbehagkñúgEdlsþúkTwkenam. urine : Liquid waste filtered from the body by the kidneys. Twkenam ³ sMNl;rav EdleRcaHecjBIsarBagÁkayedaytMrgenam.

uriniferous tubule : One of the tubules in the kidney extending bMBg;bgðÚrTwkenam ³ bMBg;kñúgtMrgenamEdllatsn§wgBIGgÁtUc from a Malpighian body to the collecting tubule. ma:l;BIhuIeTAbMBg;TTYlTwkenam. urochordata : A subphylum of Tunicata chordates; often called the G‘uyr:Ukred ³ saxargénkred eKeRcInehAfa . Tunicata. urogenital : Relating to the organs, ducts, and structures of the bnþBUC-enam ³ EdlTak;TgeTAnwgsrIragÁ bMBg; nigTMrg;énRbB½n§ excretory and reproductive systems. beBa©jecal nigRbB½n§bnþBUC. uropod : A flattened appendage at the posterior end of some G‘uyr:Ub:Ut ³ ExñgragsMEb:tsßitenAcugxageRkayrbs;RKusþaesmYycMnYn. crustaceans. uterus (womb) : Muscular organ in which the embryo develops; in s,Ún ³ srIragÁsac;dMuEdlkñúgenaHGMRb‘Íy:uglUtlas;. cMeBaHstVfñak; many lower animals, a long tube where eggs are stored. TabCaeRcIn CabMBg;EvgEdlkaEm:tjIRtUv)ansþuúk. utricle : That part of the inner ear containing the receptors for G‘uyRTIKul ³ EpñkmYyénRtecokkñúg manFµÜlsMrab;lMnwgDINamicén dynamic body balance; the semicircular canals lead from and sarBagÁkay. bMBg;Bak;kNþalrgVg;ecjBInigeTAdl;G‘uyRTIKul. to the utricle.

V vaccine : A solution of weakened or killed microorganisms injected v:ak;saMg ³ sUluysüúgmIRkUsarBagÁkayexSay rWsøab;EdlRtUv)ancak; into a patient to stimulate an immune response and so give cUleTAkñúgGñkCMgWedIm,IeP£aceGaymankarbegáItPaBsaMu. eRbobeFob immunity to a disease. Compare CamYy serum (2.) . serum (2.). vacuole : Membrane-bound, fluid-filled spaces in the cytoplasm va:KuyGUl ³ lMhPñasbitCiteBjedaysarFaturav sßitenAkñúg of a cell containing secretions, storage products, etc.. sIutU)aøsrbs;ekasika EdlpÞúksarFatubeBa©j plitplbMr:ug.l. vagina : Canal that leads to the uterus in female mammals; the pøÚveyanI ³ cMeBaHfnikstVjI CabMBg;BIeyanIeTAdl;s,ÚnEdl birth canal. CapøÚvsMrab;TarkecjmkeRkAenAeBlqøgTenø. valence-shell electron-pair repulsion (VSEPR) theory : Idea RTwsþIdMeNalénKUeGLicRtúgkñúgRsTab;v:aLg; ³ KMnitEdlfaKUén that pairs of outer-group electrons move as far apart as possible. It is RkúmeGLicRtúgRsTab;eRkAmanclnaXøatecjBIKñatamEdlGaceTA)an. used to predict the shape of the vaRtÚv)aneRbIedIm,I):an;sµanRTg;RTayénsm<½n§CMuvijGatUmmYy. bonds around an atom. valid : A term used to describe meaningful data that fit into the enAmantMémø ³ BaküeRbIedIm,IBN’naBITinñn½yEdlmanGtßn½yRtUveTA framework of scientific knowledge. nwgRbB½n§cMeNHdwgviTüasaRsþ. valine (V, Val) : One of the 20 amino acids common in proteins. v:alIn ³ GasuItGamIenmYykñúgcMeNamGasuItGamIenTaMg20énRbUetGuIn. See p. 317. emIlTMBr½ 317 .

variable (V) region : Part of an immunoglobulin molecule that is tMbn;yfaRbePT ³ Epñkrbs;mU:elKuléneKalikatUcsauMeTAnwgeraK specific to that particular molecule. i.e. that part is different in other EdlmanlkçN³yfaRbePTeTAnwgmU:elKulenaH KWfaEpñkenaHxusBI immunoglobulin molecules. mU:elKuléneKalikatUcsaMudéTeTot. variable : Any factor that can be changed or varied in an bMErbMrYl ³ ktþaEdlGacERbRbYl b¤pøas;bþÚr)ankñúgkareFVIBiesaFn_. experiment. variance (s 2) : The variation of values from the mean, calculated as va:rüg; ³ bMErbMrYléntMélecjBImFümEdlRtUv)anKNnaCakaerén the square of the standard deviation. KMlatKMrU. variegation : Color variation in different part of leaves or flowers. bMErbMrYlBN’ ³ bMErbMrYlBN’kñúgEpñkepSg²Kñaénsøwkb¤páa. It can be caused by somatic mutation affecting plastids or by vaGacbNþalmkBImuytasüúgekasikalUtlas;Edlman\T§iBlelI)aøsÞIt virus infection. b¤edaykarqøgCMgWénvIrus. vas deferens : A tube leading from the testes through which sperm bMBg;y:g ³ bMBg;ecjBIBgsVas EdldwknaMEs

vegetative cell : A cell that is neither sexually reproductive nor ekasikalUtlas;rukçCati ³ ekasikaEdlminEmnbnþBUCedayePT nig divides to form cells that are sexually reproductive; this term mineFVIcMENkedIm,IbegáItekasikaEdlbnþBUCedayePT. BaküenHsMedA particularly refers to the tube cell CaBiesseTAelIekasikabMBg;énRKab;lMGgrukçCatiGg;süÚEs

vertebrates : A subphylum of chordata characterised by a brain stVq¥wgkg ³ saxargmYyrbs;kred EdledayxYrk,alsßitenAkñúg enclosed by a skull and a backbone enclosing a spinal chord. It llad¾k,al nigqw¥gxñgB½T§CMuvijxYrq¥wgxñg. saxargenHrYmman ³ RtI includes; fish, amphibia, reptiles, GMbUrkEgáb lµÚn bkSI nigfnikstV. birds and mammals. vesicle : A tiny, membrane-bound sphere within the cytoplasm of a kUnfg; ³ fg;ragEsV‘tUc²manPñasB½T§CMuvijsßitenAkñúgsIutU)aøs. cell. vessel : A tube-like structure in the xylem that consists of vessel srés ³ TMrg;dUcbMBg;enAkúñgsIuELmEdlbgáeLIgedayFatusrésnaM elements placed end-to-end and connected by perforations; vessel bnþKña nigP¢ab;KñaedaykarTMluHrn§. FatusrésnaMdwknaMTwknigsarFatuEr:. elements conduct water and vamanenAesÞIrRKb;rukçCatiiGg;süÚEs

vitamin-deficiency disease : Poor health caused by the lack of a CMgWxVHvItamIn ³ suxPaBminl¥EdlbNþalmkBIkgVHvItamInmYycMnYn certain vitamin in the diet; for example, scurvy is caused by lack kñúgGahar. ]TahrN_ ³ CMgWsáb‘utbNþalmkBIxVHvItamInes. of vitamin C. vitamins : Organic molecules that cannot be manufactured by the vItamIn ³ m:UelKulsrIragÁEdlsarBagÁkayminGacplit)an b:uEnþman body but are required in very low concentrations in the diet for tMrUUvkarkñúgkMrity:agtickñúgGahar sMrab;karlUtlas;Fmµta nigsuxPaB. normal growth and health. vItamInrYmcMENkkMN rWGMeBIénGg;sIumekasikasMxan;sMrab;KaMBarCIvit Vitamins contribute to the formation or action of cellular rs;enA. enzymes and are essential for the maintenance of life. vitelline membrane : The noncellular membrane that PñasvIEtlus ³ eRsamPñasCuMvijekasikas‘ut. encloses the egg cell. vitreous humor : The transparent gel inside the eye behind the lens. G‘uym½rxn; ³ EpñkGn§il føakñúgEPñksßitBIeRkayEkvEPñk. viviparous : Giving birth to live young. vIvI)a: ³ EdlekItkUnecjBIkñúgépÞeBaH. vocal cords : The membranes within the larynx that vibrate to ExSsMelg ³ PñaskñúgbMBg;sMelgEdlj½redIm,IIbegáItsMelg. produce sound. voltage : A measure of the electrical potential difference that v:ul ³ rgVas;énplsgb:Utg;EsülGKÁIsnIrvagcMnucBIrepSgKña b¤vtßúBIr exists between two different points or objects. xusKña. voluntary muscle : Skeletal muscles under conscious control. sac;dMuectna b¤sac;dMuqnÞ³ ³ sac;dMuCab;q¥wgEdlsßiteRkamkarRtYt See striated muscle. Binitürbs;xYrk,al. emIl striated muscle . voluntary nervous system : See somatic nervous system somatic nervous system. RbB½n§RbsaTqnÞ³ ³ sUmemIl . vomerine teeth : Very small teeth lining the margin of the upper jaw eFµjRkGUm ³ eFµjtUc²EdlduHelIEKmfÁamelIrbs;kEgáb. in frogs. W W, Z chromosomes : Sex W, Z chromosomes in species where the RkUmU:sUm ³ RkUUmU:sUmePTkñúgRbePT EdlePTjICaePTeGetrU:UkaEm:t female is the heterogametic sex W,Z (W,Z). ¬ ¦. warm-blooded : Maintaining a constant internal body temperature. efrkMedA ³ EdlrkSasItuNðPaBkñúgxøÜneGayenAefr. See homeotherms. emIl homeotherms . warning coloration : Any brightly colored body markings of inedible BN’RBman ³ BN’sarBagÁkayPøW²dUcstVl¥itsIumin)an EdlsMrab; insects that ward off possible predators. RBmanstVrMBa. water ionization constant (K w) Product of hydronium ion and efrGIuy:ugkmµénTwk ³ plKuNénkMhab;GIuy:ugGIuRdÚj:Úmnig GIuy:ug hydroxide ion concentration in + - –14 Kw = [H 30 ][0H ] = 1 x 10 water solutions. GIuRdúksIutkñúgsUluysüúgTwk . . –14 Kw = [H30+][0H-] = 1 x 10 water mould : A type of saprobe or parasite fungus that lives in pSitTwk ³ RbePTsa®bUb rWpSit)a:ra:suIt Edlrs;enAkñúgTwksabrWdIesIm. fresh water or moist soil.

water potential : The sum of two opposing forces (osmosis and b:Utg;EsülTwk ³ kMlaMgBIrEdlmanTisedApÞúyKña ¬sMBaFGUsµÚs turgor pressure) that can cause the movement of water into and out of nigsMBaFe)a:g ¦ EdlGaceFVIeGayTwkcUlnigecjBIekasika. a cell. water uptake : The path of water from soil to leaves, that is caused karRsUbTwkeLIg ³ dMeNIrTwkBIdIeTAsøwk EdlbNaþlmkBIbnSMén by a combination of: osmosis, transpiration pull, cohesion- )atuPUtGUsµÚs TMnajénrMPaycMhayTwk Pabhab;tg;süúg ExPIl½rrIFI tension, capillarity, and root nigsMBaFb¤s. pressure. water vascular system : A series of water-filled canals in the body RbB½n§bMBg;Twk ³ es‘rIbMBg;manTwkkñúgsarBagÁkayeGKINUEDm Edl of an echinoderm that functions in locomotion. manmuxgarbMlas;TI. wave velocity : Speed at which a wave moves through a material; it el,Ónrlk ³ el,ÓnEdlrlkpøas;TIqøgkat;rUbFatumYy. vaGaRs½yeTA depends on the material and the type of wave, not the frequency of nwgrUbFatu nigRbePTrlkminGaRs½yelIeRbkg;énrlkeT. the wave. wavelength : Length of one wave; mathematically equal to the wave CMhanrlk ³ RbEvgrlkmYyEdlKNnatamKNitviTüaesIµnwgel,Ón velocity divided by the frequency. eg. visible light has wavelengths rlkEcknwgeRbkg;. ]TahrN_ ³ BnøWEdlGacemIleXIjmanCMhan between 400 nm (violet) and 750 rlkBI 400 nm ¬BN’sVay ¦nig 750 nm ¬BN’Rkhm ¦. nm (red). wax : A fatty acid combined with a long-chained alcohol. RkmYn ³ GasIutxøaj;pSMCamYyRcvak;Gal;kuly:agEvg. weak acid : Molecule or ion with a lesser tendency to give up GasIutexSay ³ m:UelKulb¤GIuy:ugEdlmanTMenare)aHbg;GIuy:ugGIuRdÚEsn + hydrogen ions than H 30 . eg. exSayCagGIuy:ugGIuRdÚj:Úm . ]- CH 3COOH . CH 3COOH weed : Any plant that competes with a plant that is important to rukçCaticéRg ³ rukçCatiTaMgEdlRbECg ¬bMpøaj ¦CamYyrukçCatiEdlman people. eg. plants that compete with rice. sarsMxan;cMeBaHmnusS. ]TahrN_ ³ rukçCatiEdlbMpøaj®sUv. weight : The force that a mass exerts downward on the earth, TMgn; ³ kMlaMgEdlm:assgát;eTAelIEpndI ehIyEdlGaRs½yeTAelI which depends on the gravitational field strength. Measured in kMlaMgTMnajEpndI. vaRtUv)anKitCajÚtun. vaRtUv)aneKeRbIpøas;bþÚr Newtons. Used in everyday KñaeTAvijeTAmkkñúgPasaniyayerogral;éf¶CamYyBaküm:as. language interchangeably with mass. Western blotting : A technique Western used to transfer the pattern of karpþit ³ bec©keTsEdleKeRbIsMrab;bBa¢ÚnKMrU®bUetGuInEjk proteins separated by gel gel electrophoresis electrophoresis, to a membrane like eday eTAelIPñasdUcRkdassMrab;viPaKbnþeTot. paper, for further analysis. wetland : Any area usually covered by shallow water with tMbn;dIesIm ³ tMbn;EdlCaTUeTARKbdNþb;edayTwkrak;² ehIyman plants and animals specially adapted to live there. rukçCati nigstVEdlsMrbxøÜnCaBiessedIm,Irs;enATIenaH. white blood cells, leucocytes : Any one of several colorless cells ekasikaQams b¤LWkUsIut ³ ekasikaKµanBN’EdlmanmuxgarkarBar that function in protecting an organism against infection. sarBagÁkayTb;Tl;nwgkarbgáCMgW. white matter : Nerve tissue in the central nervous system consisting rUbFatus ³ CalikaRbsaTenAkñúgRbB½n§mCÄmNÐlRbsaT Edlbgá mainly of myelin covered axons (nerve fibres). eLIgCasMxan;edayemJlIn RKbBIelIGak;sUn ¬srésRbsaT ¦.

white muscle fibre : Part of skeletal muscle that can respond sréssac;dMus ³ Epñkénsac;dMuqñÚt EdlGaceqøIytbya:grh½s. very quickly (fast twitch). whorl : A circular group of at least three leaves or flower parts all ragrgVg;vil ³ Rkumsøwky:agticbI b¤EpñkTaMgLayrbs;páaEdlP¢ab;eTAnwg attached to an axis at the same level. G½kSRtg;kMritdUcKñaCargVg;vil. wild type : The most commonly observed phenotype or genotype, RbePTFmµCati ³ epNUTIb b¤ esNUTIbEdleKGegáteXIjjwkjab; usually called ‘normal’ or standard. bMput ehIyeRcInEtRtUv)aneKehAfa ;Fmµta ; b¤sþg;da. wilting : The loss of turgor in a plant. RseBan ³ kar)at;bg;PaBe)a:grbs;rukçCati. withdrawal symptoms : A characteristic group of symptoms eraKsBaØadkfy ³ lkçN³énRkumeraKsBaØaEdlekIteLIgbnÞab;BIkar that occurs after use of a drug has been stopped by a person that is Qb;eRbIfñaM cMeBaHGñkejonfñaM. ]- dUcCaGñkFøab;eRbIfñaMejon enAeBl physically dependent on a drug. EdlQb;eRbI GñkenaHnwgeTACaht; b¤j½r. wobble hypothesis : An idea Francis Crick proposed by Francis Crick which smµtikmµv:bb‘l ³ KMnitEdlesñIedayelak EdlEcgfa states that the third base in an anticodon can be changed in )asTIbIkñúgGg;TIkUdugGacRtUv)anpøas;bþÚrkñúgrebobCaeRcIn edIm,IGaceGay several ways to allow it to vaTTYlsÁal;)aseRcInCagmYykñúgkUdug ARNm . recognize more than one base in the codons of mRNA. womb : See uterus. s,Ún ³ emIl uterus . wood : The xylem of gymnosperms and angiosperms. sac;eQI ³ sIuELmrbs;sIumNUEs

xerophyte : A plant adapted for growth in dry conditions. Compare rukçCatiFn;sMgYt ³ rukçCatiEdlsMrbsMrYlkarlUtlas;eTA nwg hydrophyte, mesophyte. l½kçx½NÐGakasFatus¶Üt. eRbobeFob hydrophyte, mesophyte . X-Linked gene : A gene located X X on one of the sex-determining X EsnCab;RkUm:UsUm ³ EsnsßitenAelIRkUm:UsUmePT . chromosomes. X-ray : High energy radiation that can penetrate very deeply and kaMrsIµGiuc ³ rsµIfamBlx

yolk : The food store in the eggs of most animals made up of fat and s‘utelOg ³Gaharsþúkkñúgs‘utrbs;stVPaKeRcInEdlbgáeLIgedayxøaj; protein granules that nourish the developing embryo. Almost absent nigRKab;RbUetGuIn sMrab;ciBa©wmGMRb‘Íy:ugEdlkMBugEtlUtlas;. esÞIrEtKµan in mammals since food is provided cMeBaHfnikstV eRBaHGaharRtUv)anpþl;eGayedaymþaytamry³Tgsuk. by the mother through the placenta. yolk sac : A membrane that surrounds the yolk of an egg in fg;elOg ³ PñasEdlB½T§CMuvijs‘utelOgéns‘utbkSI lµÚn nigfnikstV. birds, reptiles, and mammals. Z Z-chromosome : See W, Z Z W , Z chromosomes chromosomes. RkUm:UsUm ³ emIl . Z-DNA : An alternate structure of AND Z : ADN DNA which has a left-handed - TMrg;epSgén EdlmanExSex©AeTVrmYleqVg. double helix. Z-DNA may have a ADN-Z role in the regulation of gene GacmannaTIkñúgtMrUvkarsMEdgecjrbs;Esn. expression. zeatin : A natural cytokinin (Zea mays) isolated from corn (Zea mays). esGaTIn ³ suItUKInInFmµCatiEdlEjkecjBIeBat . zein : A simple storage protein in the kernels of corn,lacks esGIun ³ RbUetGuInbMruggayenAkñúgRKab;eBat EdlKµanRTIbtUpan nig tryptophan and lysin. lIsIun. zinc finger : A folded amino acid chain, like a finger, that is held Rmams½gásI ³ Rcvak;GasuItGamIenEdlbt;dUcRmaméd P¢ab;Kñaeday together by a Zinc ion. This feature is possessed by various proteins GuIyu:gs½gásI. lkçN³BiessenHmankúñgRbUetGuInCaeRcIn EdlP¢ab;eTA that bind to DNA and act as nwg ADN nigedIrtYCaGñktMrUvkñúgkarcMlgRkm. transcription regulators. zona pellucida : A mucoprotein membrane that surrounds the egg tMbn;EBluysIut ³ PñasmuykURbUetGIunEdlB½T§CMuvijkaEm:tjIrbs; of mammals. It is secreted by the ovarian follicle cells. fnikstV. vaRtUv)anbeBa©jedayekasikapUlIKulGUEv. zone of elongation : An area behind the meristem where plant tMbn;lUtRbEvg ³ EpñkenAxagelIemCalika EdlekasikarukçCati cells grow in length. lUtlas;RbEvg. zone of maturation : An area behind the zone of elongation tMbn;BMenjv½y ³ EpñkenAxagelItMbn;lUtRbEvg EdlekasikarukçCati where plant cells begin to differentiate. rWekasikastVcab;epþImeFIVbMElgÉkeTs. zooid : A single member of a colony. sUGIut ³ smaCikmYyénkULÚnI. zooplankton : Tiny heterotrophic organisms that float on or near the stþbøg;tug ³ Pavrs;brCIBtUc² EdlGENþtenAelIépÞTwk b¤enAEk,rép Þ surface of a body of water. The animal component of the plankton, Twk. smasPaKstVénbøg;tugEdlmanlTæPaBbMlas;TImankMritEt having only limited ability to b:ueNÑaH. move. zoospore : Flagellated spores. sUs,: ³ s,:Edlman)aøEsl. zwitterion : Dipolar ionic form of an amino acid that is formed by eTVtaGIuy:ug ³ sNæanGIuy:ugb:UlBIrénGasIutGamIenEdlekIteLIgedaykar + donation of an H from the pþl; H +BIRkúmkabuksIuleTAeGayRkúmGamIn α. edaysarvtþmanbnÞúkTaMg carboxyl group to the α-amino group. Because both charges are BIreFIVeGaybnÞúkBitmanPaBNWt. present, the net charge is neutral.

zygapophysis : Articular process of the neural arch of a vertebrate. sIukab:UPIs ³ snøak;énFñÚsnøak;qw¥gxñgrbs;stVq¥wgkg. emIl See also postzygapophysis and postzygapophysis and prezygapophysis prezygapophysis . . zygodactylous : Type of foot, in which the toes are arranged in two sIukUdak;TIl ³ manRbePTeCIgEdlRmamtMerobCaBIrRkumpÞúyKña. opposable groups. zygomycetes (zygomycota) : A large group of fungi with primarily sIukUmIEst ³ RkumpSitd¾FMmYy EdlmanmIeslüÚmsWNUsIut. vabnþBUC coenocytic mycelia; they reproduce asexually by spores produced eday\tePTedays,:Edlplitkñúgs,:r:g;. karbnþBUCedayePTeday within sporangia; sexual )atuPUtCMnab;bþÚr mankMNsIukUs,:r:g;. reproduction by conjugation includes the formation of zygosporangia. zygosporangium (plural: ( Zygosporangia) : zygosporangia ) : A sporangium sIukUs,:r:g; Bhu> s,:r:g;pÞúksuIkUs,:PñasRkas;man containing a thick-walled, multinucleate zygospore that éNVy:UeRcIn EdllUtlas;kñúgsIukUmIEstbnÞab;BIkarrlaycUlKñaén develops in zygomycetes after the GuIsUkaEm:t. fusion of isogametes. zygospore : A diploid zygote with a thick outer layer. sIukUs,: ³ sIukUtDIbøÚGIutEdlmanPñaseRkARkas ;. zygote : The diploid cell formed by the union of a male and a suIkUt ³ ekasikaDIbøÚGIutEdlbgáeLIgedaykarrlaycUlKñaénkaEm:t female gamete; the fertilized egg. eQµal nigkaEm:tjI. s‘utbgákMeNIt. zygotene : A stage of prophase I in I meiosis in which the homologous suIkUEtn ³ vKÁmYykñúgRbUpas énemyU:sEdlkñúgenaHRkUmU:sUmGUmU:LÚk chromosomes synapse and pair forming bivalents. The P¢ab;nigpÁÚKñabegáItCaTMrg;b‘Íva:Lg;. kuMpøicsIuNab;sIusenHbgáeLIgenAvKÁ synaptonemal complex forms at enH. this stage. zymogen : Inactive form of an enzyme that is activated by sIum:UEsn ³ TMrg;GskmµénGg;sIumEdlRtÚv)aneFVIeGayskmµeLIg cleavage of one or more peptide bonds. edaykarkat;pþac;sm<½n§biubTItmYyb¤eRcIn.