Levels of Organization in Organisms 47 Lonumber=6L1 0210; Correctionkey=NL-B DO NOT EDIT--Changes Mustbemadethrough “Fileinfo” 48 Move Andattach Tohostcells

LONumber=6L1_0210; CorrectionKey=NL-A DO NOT EDIT--Changes mustbemadethrough "Fileinfo" 46 Unit 2 Organisms asSystems Levels of Organization of Levels each levelinanorganism. you willbeabletorelate structure tofunctionat By theendofthislesson . . it liveson,andalsoprovides aprotective armor. The hard shellofthethornbughelpsitblendinwith theplant in Organisms in LESSON 1 LESSON

Go online to view the digital version of the Hands-On Lab for this lesson and to download additional lab resources.

CAN YOU EXPLAIN IT?

How can systems with such different structures perform the same function?

esophagus stomach

intestine crop esophagus mouth gizzard stomach intestine stomach stomach mouth

Cows are animals that eat grass, hay, and other hard-to-digest plants. Earthworms are animals that live in soil and eat decaying plant and animal matter.

1. The cow’s digestive system and the worm’s digestive system both break down food, but they do not look the same. Compare and contrast the two systems. What explanation can you suggest to explain the similarities and differences between the two digestive systems? © Houghton Mifflin Harcourt • Image Credits: ©Cindy Singleton/iStockPhoto.com © Houghton Mifflin Harcourt • Image Credits:

EVIDENCE NOTEBOOK As you explore the lesson, gather evidence to help you explain the structures of the two digestive systems.

Lesson 1 Levels of Organization in Organisms 47 LONumber=6L1_0210; CorrectionKey=NL-B DO NOT EDIT--Changes mustbemadethrough “Fileinfo” 48 move andattach tohostcells. whip-like structures thathelpthem E. colibacteriaare unicellular. Theyhave throughout thetree. These cellsconnecttogether toformatissue, calledvasculartissue , thattransports water function. For example,certainspecialized cellsintheoaktree are small andhollow. tissues. Atissue isagroup ofsimilarcells thatare organized toperform aspecific In organisms, suchasplants andanimals,specializedcellsare grouped togetherin Tissues 2. Discuss one leveloforganization. and organized toperformspecificfunctions.Multicellularorganisms havemore than of more thanonecell.Thecellsthatmake upamulticellularorganism are specialized functions neededforlifeare performedbyonecell.Multicellularorganisms are madeup unicellular organisms. Unicellularorganisms haveoneleveloforganization. Allthe processes neededforlife.Organisms thatare madeupofasinglecellare called An organism isalivingthingmadeupofoneormore cellsthatcanperformallthe Cells only asinglecell. living thingsare madeupofmultiplesubsystems.Otherlivingthingsare asystemof Every livingthingisasystemthatperformsalltheprocesses needed forsurvival.Some Organized Living ThingsAre Unit 2 Organisms asSystems think havingspecializedcellsisanadvantageforamulticellular organism? Exploring Levels of Organization in Organisms Multicellular organisms can bemadeupofbillionscells.Howdoyou specialized stemcalledatrunk. many leavestocapture sunlightanda Oak trees are multicellular. Theyhave EXPLORATION 1 whiskers tohuntunderwater. multicellular. Itusesitssensitive The Eurasian watershrew is

© Houghton Mifflin Harcourt • Image Credits: (tl) ©BSIP/UIG/Universal Images Group/Getty Images; (tc) ©Raimund Linke/Photodisc/Getty Images; (tr) ©CreativeNature_nl/istock/Getty Images Plus/Getty Images DO NOT EDIT--Changes must be made through “File info” LONumber=6L1_0210; CorrectionKey=NL-B

Organs Different types of tissues that function together form an organ. For example, the stem of the oak tree is an organ that is made up of vascular tissue that transports water, ground tissue that provides support, and epidermal tissue that protects the outside of the stem. Blood vessels are organs in the shrew made up of epithelial tissue that controls the passage of blood cells, layers of smooth muscle tissue that control the diameter of the vessel, and a tough wall of connective tissue.

connective tissue epidermal tissue

smooth muscle vascular tissue

ground tissue red blood cells

epithelial tissue

Stems are plant organs that transport materials Blood vessels transport blood and nutrients and and provide support for the plant. remove wastes in the body.

3. Use the oak tree stem as evidence to support the claim that specialized tissues work together to form organs that perform necessary functions. ©Steve Gschmeissner/Science Photo Organ Systems An organ system is a group of organs that work together to perform body functions. The leaves, stems, and flowers are organs of the shoot system of the oak tree. In the

©Biophoto Associates/Science Source shrew, a muscular heart and blood vessels are organs of the circulatory system that

; (tl) delivers blood to all the cells in the shrew’s body. An organism can have many organ systems that work together to perform all the functions the organism needs to survive.

4. Draw a diagram that shows the relationship between cells, tissues, organs, and

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Analyze Levels of Organization in a Lizard

When this frilled lizard is threatened, its heart rate increases in preparation to fight or to run away. The lizard stands on its back legs, hisses, and expands the large skin flap that surrounds its neck.

Cardiac muscle cells are specialized for contraction. The structure of protein fibers in the cell allows it to stretch and contract.

Cardiac muscle cells branch and connect to each other to form cardiac muscle tissue. Special junctions where the cells connect allow all the cells in the tissue to contract at the same time.

The heart is an organ in the circulatory system. The many cells stretching and contracting together make the heart stretch and contract, pumping blood as it changes shape.

5. Is the frilled lizard unicellular or multicellular? Use evidence to explain your answer.

6. Use frilled lizard as evidence to support the claim that organs work together to form organ systems that perform necessary functions. ©Auscape/Universal Images Group/Getty © Houghton Mifflin Harcourt • Image Credits: Images

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© Houghton Mifflin Harcourt • Image Credits: (l) ©Biophoto Associates/Science Source; (r) ©Ed Reschke/Photolibrary/Getty Images their function. You willmodeltwodifferent tissue typesandrelate theirstructure to Procedure andAnalysis the heelsofyourfeet. abrasion. Itcanbeespeciallythickon This tissue protects theskinfrom STEP STEP STEP ook atthetissues inthephotos.Record your observations STEP

1 4 3 2

Describe howyour connected toformtissues. Constructamodelofeachtissue. Choose thematerialsthatyouthinkwillbestmodelcellsandhowtheyar L of tissues withinanorgan dependonthestructure ofitscells. Use yourmodelstomak tissues. about thestructure andshape ofthecells. Model Tissue Structure and Function Lab Hands-On models represent groups ofcellsworkingtogether toform e aclaimabouthowtherole playedbydifferent types heart pumpblood. stretches andcontracts tomake the This tissue islocatedintheheart.It Lesson 1Levels ofOrganization inOrganisms • • • • • • • • • putty • • • • • MATERIALS

scis rubber rice pompoms modeling mark glue foam construction car beads adhesive tape sponges dboard sors ers peanuts bands e clay paper 51 LONumber=6L1_0210; CorrectionKey=NL-B DO NOT EDIT--Changes mustbemadethrough “Fileinfo” 52 10. Discuss Categorize aLevel of Organization Unit 2 Organisms asSystems fluid, orboth.Supportyour argument withevidence. body fightinfection.Witha partner, discuss whetheryouthinkbloodisatissue, a the cellsinbodywithoxygen,helpsregulate bodytemperature, andhelpsthe Blood containsred bloodcells,whiteandplatelets.Bloodprovides all There are 1billion,or10 measure themass ofcellsandothermicroscopic structures. Biologists useaunitofmeasure calledananogram (ng)to Have youeverwondered howmanycellsare inyourbody? Do theMath 8. 9. Thegizzard inthe earthwormcontainssmallstonesthathelpgrindup 7. EVIDENCE NOTEBOOK 400 grams? how manycellsare inthebodyofahedgehogthatweighs If theaverage mass ofacellis1nanogram, approximately is themass ofthepancreas? pancreas hasamass of4grams. Whatpercent ofthehedgehog’s totalmass The pancreas isanorgan thatispartofthedigestivesystem.Thehedgehog’s STEP 1 STEP 1 STEP 2 STEP 2 not? Record yourevidence. bits offood.Whymighttheearthwormhaveagizzard butthecowdoes Blood ismadeupofbloodcellssuspendedinaliquidmatrix calledplasma. Convert400grams tonanograms. Write theratio ofthemass ofthepancreas tothetotalmass ofthe Use theratio Multiplyby100toconvert percent. hedgehog. hedgehog. __ 400 g× 400 g(totalmass) | AnalyzeSizeandScaleinOrganisms 4 g(pancreas) _ 10 9 1g , nanograms in1gram. 9 ng _ 1 cell 1 ng

tofindthenumberofcellsinbody

= ng× × 100= _

1 cell 1 ng

ng winter sleep. This hedgehogisbeingweighedbefore his % cells

© Houghton Mifflin Harcourt • Image Credits: (t) ©Geoff du Feu/Photodisc/Getty Images; (bl) ©Innerspace Imaging/Science Source; (bc) ©Science Source; (br) ©Silvia Riccardi/ Science Source Thetissue thatlinesthe intestine helps 11. organism thesameway. lip todrinkfrom. Structure-function relationships existatalllevelsoforganization inan thin, soit’s easytohold.Thewaterbottle hasahollowspacetoholdliquidandsmooth a relationship betweenthestructure andfunctionof these objects.Thepencilislongand Think ofanobjectortoolthatyouuseeveryday, suchasapencilorwaterbottle. There is type thatitismadeof. plant stem,are stiff andregularly shaped.Atissue hascharacteristics similartothecell can take anyshape.Butcellsthatformaprotective barrier, suchasthecellsthatcovera perform. For example,cellsthatengulfharmfulparticlesinthebody are flexibleand All organisms are madeofcells,butnotallcellsare thesame.Cellsare fitforthejobthey Structure and Function of Cells and Tissues Structure and Function of Animal Tissues Explore thephotograph oftherat tissues toseehowthestructure relates tofunction. Relating Structure Function to in Living Things The musclecellsare organized intoflexiblefibers becausemuscletissue elongatesand absorbs /protects /contracts /destroy /ingest connect nutrients byincreasing theintestinalsurfacearea. Thelong extensionsofnervoustissue organized intostretchy fibers. tissue ismadeupofmusclecells holes. Theskeletal muscle that cansqueezethrough small Rats havelong,flexiblebodies the cellsinbrain andother partsofthebody. release /absorb /break down EXPLORATION 2 the surfacearea. finger-like projections thatincrease tissue thatlinestherat intestinehas almost anythingtheycanfind.The Rats are omnivores andwilleat . Lesson 1Levels ofOrganization inOrganisms long, branching extensions. up thenervoustissue have sources. Thecellsthatmake Rats canremember food

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Structure and Function of Organs Just as the structure of a cell or tissue relates to its function, the structure of an organ relates to the function it performs. For example, some organs are shaped like hollow tubes to transport materials, such as the vessels that carry blood throughout your body. Others are sac-like to hold materials, such as your stomach that stores food and your lungs that expand to hold air.

Tulip flowers are organs that contain the flower structures the stem plant uses to reproduce. They come in a wide variety of shapes and colors.

leaf

12. Look at the photo of the tulip. Record your observations about the structures of the organs in the tulip shoot system.

Organ Structural Observations Functions

transports nutrients stem and stores water, supports plant

captures sunlight for leaf making nutrients, regulates water loss

attracts animal flower pollinators

13. Leaves are made of a protective tissue that protects against water loss, ground tissue for support and storage, and transport tissue to move water and nutrients. Compare and contrast the thickness of the protective tissue you would expect to find on a leaf of a plant that lives in a wet habitat with the leaf of a plant that lives in a

dry habitat. ©leuntje/Moment/Getty Images © Houghton Mifflin Harcourt • Image Credits:

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© Houghton Mifflin Harcourt • Image Credits: ©Peter Schoen/Moment/Getty Images 5 15. 4 14. specialized organs are workingtogether. able toexchangegasesmore effectively because that haveamore complexrespiratory systemare exchange thesegasesthrough theirskin.Animals that donothavearespiratory systemsimply oxygen andreleases carbondioxide.Someanimals system isananimalorgan systemthattakes in specialized functions.For example,arespiratory Most organisms haveorgan systemsthatperform Systems Organ of Function and Structure 6 16. needs forflight. respiratory systemprovides theenergy thebird Describe howthestructure ofthebird breathe Birds haveairsacsandlungs.Whenbirds in /out lungs andairsacs.Whenbirds breathe supply ofoxygen- the airsacs.Thismeansthatbirds alwayshavea lungs, andstored fresh airentersthelungsfrom organization ismadeupofasysteminteracting parts. systems, whichare allmadeupofcells.Inyourargument, explain howeachlevelof Develop anargument thatexplainshowanorganism ismadeupinteracting body in /out Relate Cells to Organ Systems Sm Language , theoxygen-poorairleaves rich /poor , oxygen-richairfillsthe Arts air. insects. Scarlet macawsflylongdistancestofindfruit,nuts,and Lesson 1Levels ofOrganization inOrganisms air sacs lung 55 LONumber=6L1_0210; CorrectionKey=NL-B DO NOT EDIT--Changes mustbemadethrough “Fileinfo” 56 Look atthephotoofsailfish.Thinkabout 17. possible functionsandresponses. of systemsgivesanorganism agreater varietyof together toperformfunctions.Thecoordination In multicellularorganisms, bodysystemswork avoid predators, andtravel towarmertemperatures. oxygen. Theyneedtomovefindfoodandmates, Organisms needtoprocess nutrientsandtake in Functions Perform to Interact Systems Body Unit 2 Organisms asSystems ideas inthetable. respond totheirenvironment. Record your what theseorganisms need, andhowthey warm up food Need 18. EVIDENCE NOTEBOOK Analyzing Body System Interactions the structure ofthecow’s digestive system?Record yourevidence. that itcanbefullybroken down. What factordoyouthinkcontributesto In thecow, foodtravels through fourdifferent stomachcompartments so Response travel to different location swim faster EXPLORATION 3 are workingtogethertohuntaschoolofsardines. Sailfish are thefastestfishinocean.Thesethree sailfish

© Houghton Mifflin Harcourt • Image Credits: (t) ©Jim Cummins/The Image Bank/Getty Images; (c) ©Hero Images/Corbis; (b) ©Tetra Images/Getty Images Human Body SystemsHuman Body The 19. The The The The The The away from thecells. carbon dioxideandotherwasteproducts and oxygentoallcellsinthebody. Itcarries wastes from thebody. waste from thebody. into essential nutrientsandexpelssolid between thebrain andtheenvironment. movement andcoordinates communication makes bloodcells. protects organs, allowsmovement,and the digestivesystem. the hearttobeat,andmovesfoodthrough releases carbondioxideaswebreathe. shown. working togethertoperformthefunction activities. Decidewhichorgan systemsare photographs ofpeopleinvolvedindifferent organ systemsare involved?Look atthe When youperformanactivity, which respiratory system takes in oxygen and circulatory system deliversnutrients excretory system removes liquid digestive system breaks downfood nervous system controls body skeletal system supportsthebody, muscular system movesbones,causes B. The Bodyfunctionsslowdown asyousleep, C. A. The to delivernutrients throughout thebody. arms tomove,spinningthewheelsofthisbike. but theydonotstop!For example,the student tobreathe andread music. excretory /skeletal muscular /circulatory /excretory digestive nervous/circulatory to break downfood,and the muscular /digestive respiratory/excretory Lesson 1Levels ofOrganization inOrganisms systemsallowthe systemcontinues systems allowthis systemcontinues and and 57 LONumber=6L1_0210; CorrectionKey=NL-B DO NOT EDIT--Changes mustbemadethrough “Fileinfo” 58 Make adiagram thatshowsthestepsofmakingpaper intopulp.Howdoyouthink 22. Whatneeddoestheplantdigesterfill?Howthiscompare totheneedthatan 21. and ready forprocessing intopaper. a screen where itisbleachedanddried.Thepulpthencut,stacked, to awasherwashawaythecookingliquid.Thepulpisspread outon pulp. After passing through allthecookingchambers,pulpissent pressure tobreak downthefibersinwoodtomake amaterialcalled cooking chambers.Theprocess useschemicals,heat,and wood chipscutfrom trees intoatall,cylindricaltowerthathasmultiple products, suchaspaper. Thepapermakingprocess beginsbyfeeding Humans useanindustrialprocess todigestplantmatter forusein 20. Unit 2 Organisms asSystems this process compares tothedigestionoffoodbyanimals? animal’s digestivesystemfills? the otherbodysystemsofhummingbird. affecting themuscularsystemwouldaffect place toanother. Describehowadisease rely ontheirstrong wingstomovefrom one Hummingbirds havesmall,weakfeetand Designed Systems Designed Compare Natural and It Engineer This hummingbird’s wingsbeatmore than50timespersecond! into paperfornewsprint. This pulpslurrywilleventuallybemade

© Houghton Mifflin Harcourt • Image Credits: (t) ©Forrest Brown/Creatas Video/Getty Images; (b) ©Tom Hollyman/Science Source DO NOT EDIT--Changes must be made through “File info” LONumber=6L1_0210; CorrectionKey=NL-B

TAKE IT FURTHER

Continue Your Exploration

Name: Date:

Check out the path below or go online to choose one of the other paths shown.

• Hands-On Labs Go online to Biomimicry choose one • Engineering Organs and Tissues of these other • Propose Your Own Path paths.

No matter what you want to do with a machine or process, there is a good chance that there is an organism that does it naturally. Biomimicry, or biomimetics, uses design solutions found in nature to solve human design problems. For example, researchers are always looking for ways to make a strong yet flexible fiber. One of the strongest known materials is spider silk. Scientists study spider webs to find out what the silk is made of. If researchers could manufacture synthetic spider silk, it could be used in a wide range of applications. Surgery sutures and wound covers, artificial ligaments and tendons, protective clothing, and fishing nets are some examples of the potential applications using synthetic spider silk.

1. Why do you think more scientists today are turning to nature to solve engineering and design problems? Select all that apply. A. Clean and sustainable design solutions could help solve environmental issues, such as pollution. B. Scientists are running out of ideas for design and engineering solutions. C. Greater understanding of the natural world has led to the discovery of new possibilities for design solutions. © Houghton Mifflin Harcourt • Image Credits: ©Bjorn Grotting/Alamy © Houghton Mifflin Harcourt • Image Credits:

The silk of spiders is incredibly strong, lightweight, and flexible. Scientists hope the silk will replace human-made materials that are not as strong, not as flexible—and not as environmentally friendly.

Lesson 1 Levels of Organization in Organisms 59 DO NOT EDIT--Changes must be made through “File info” LONumber=6L1_0210; CorrectionKey=NL-B

TAKE IT FURTHER

Continue Your Exploration

Scientists have discovered that brittle stars are covered in The biomimetic lenses based on the brittle star lens structure thousands of microscopic lenses that may help them avoid are soft, providing better fine-tuning and complexity than predators. These lenses transmit light more perfectly than conventional hard lenses. The microlenses shown here are any human-made lens. part of a device that is used in digital cameras.

2. Engineers often use designs that mimic shapes found in nature, such as flippers, wings, and beaks. Construct an argument that supports the use of structure-function relationships found in nature in engineering and design. Use the examples as evidence.

3. Sustainability experts help communities, companies, and governments adopt operating practices that are environmentally friendly. They seek to reduce pollution and waste and to increase recycling of resources. How might sustainability experts apply biomimicry to their field? © Houghton Mifflin Harcourt • Image Credits: (l, inset) ©Lucent Technologies’ Bell Labs/ Technologies’ inset) ©Lucent (l, © Houghton Mifflin Harcourt • Image Credits: Source Wootton/Science Science Source; (r) ©Paul

4. Collaborate Brainstorm characteristics of organisms that you think could be used to solve design problems. Choose one idea and make a sketch with an explanation of the connection to nature and the problem it addresses. Review the ideas of other groups. Practice skepticism as you evaluate their claims for how their solution would solve a design problem.

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LESSON 1 SELF-CHECK

Can You Explain It?

Name: Date:

How can systems with such different structures perform the same function?

EVIDENCE NOTEBOOK Refer to your initial explanation about the digestive systems and the notes in your Evidence Notebook. These can help you construct an explanation for why these systems have different structures.

1. State your claim. Make sure your claim fully explains the similarities and differences between the two systems.

2. Summarize the evidence you have gathered to support your claim and explain your reasoning. © Houghton Mifflin Harcourt • Image Credits: ©Cindy Singleton/iStockPhoto.com © Houghton Mifflin Harcourt • Image Credits:

Lesson 1 Levels of Organization in Organisms 61 LONumber=6L1_0210; CorrectionKey=NL-B DO NOT EDIT--Changes mustbemadethrough “Fileinfo” 62 Use the photograph of the plant to answer 5–6. Questions 3. 3–4. Questions Study the diagram of the kidney to answer understanding of the lesson. your following to check the questions Answer 4.

Unit 2Organisms asSystems liquid wastefrom thebody. The urinarysystemworkswiththe D. C. B. A. is true? Based ontheinformation,whichstatement nephron ismadeupofcellsthatworktogether. filtering structures callednephrons. The Each kidneycontainsmor The urinarysystemisasubsystemofthe Kidneys ar

The nephr organ system. The nephr system. The kidneycanbedefinedasanor The nephr e organs intheurinarysystemthatremove wasteproducts from theblood. on canbedefinedasatissue. on canbedefinedasan on canbedefinedasanorgan. e than1million circulatory /digestive LESSON 1 SELF-CHECK 1 LESSON Checkpoints gan excretory / digestive excretory /digestive 6. 5. without waste blood

These materialsare transported bythestem,a(n) that absorbswaterandnutrientsfrom thesoil. D. A. this plant? What levelofor in theplant. C. B. tissue / organ system. Eachroot isa(n) The under waste blood

with

or or tis cell kidney gan system gan sue urine ground portionofthisplantistheroot systemtoremove ganization isasingleleafof system. thatispartoftheshootsystem tissue /organ blood flow nephron urine flow

© Houghton Mifflin Harcourt • Image Credits: (t) ©Auscape/Universal Images Group/Getty Images; (c) ©Peter Schoen/Moment/Getty Images; (b) ©Jim Cummins/The Image Bank/ Getty Images an organism. Body systemsworktogethertoperformallthefunctions necessary forthesurvivalof A relationship existsbetweenstructure andfunction. Cells, tissues, organs, andorgan systemsare thelevelsoforganization inlivingthings. Complete thissectiontoreview themainconceptsoflesson. Interactive Review LESSON 1 SELF CHECK 1 LESSON C. B. A. systems inanorganism. system canaffect thefunctionofotherbody Explain whythefailure ofoneorgan ororgan an organism. Describe howstructure isrelated tofunctionin benefit amulticellularorganism? How doeshavingmultiplelevelsoforganization Lesson 1Levels ofOrganization inOrganisms 63