GAMETOGENESIS: the Making of Gametes

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GAMETOGENESIS: The making of gametes GAMETE - SEX CELL (SPERM OR EGG) GENESIS - TO MAKE OR CREATE Types of Gametogenesis SPERMATOGENESIS: Makes MALE sperm cells OOGENESIS: Makes the FEMALE egg cells Both processes use MEIOSIS as their type of cell division, however the results are quite different. Primary 46 SPERMATOGENESIS Spermatocyte Where does it occur? Secondary 23 23 In the TESTES Spermatocytes Description of Germ Cells 23 23 23 23 Spermatids GERM CELLS in the testes are DIPLOID (2N, 46) just like the rest of the body cells. Mature Sperm Cells Initial germ cells are called PRIMARY SPERMATOCYTES What is produced? 1 round of spermatogenesis produces FOUR healthy sperm cells. Every sperm cell contains a unique combination of genes. (NO TWO ARE ALIKE!) Primary Oocyte OOGENESIS 46 Where does it occur? In the OVARIES Secondary Oocytes Description of the Germ 23 23 Cells GERM CELLS in the ovaries are DIPLOID (2N, 46) just like the rest of the body cells. 23 23 23 23 1 Ootid Initial germ cells are called PRIMARY OOCYTES What is produced? X X X 1 round of Oogenesis 3 Polar Bodies produces ONE healthy egg cell (OVUM), and THREE POLAR BODIES. The polar bodies serve NO PURPOSE in the Mature Egg Cell (OVUM) body. Once gametes are formed, organisms can undergo SEXUAL REPRODUCTION and/or FERTILIZATION. Sexual Reproduction: The fusion of two gametes Fertilization: The fusion of the egg and sperm Critical Concepts/Connections How is spermatogenesis different from oogenesis? What are three sources of genetic diversity? (clue: 2 are from meiosis and 1 is from fertilization) How are the terms sexual reproduction and fertilization different? (Why might scientists need two different terms) In the creation of a child, when is meiosis necessary and when is mitosis necessary? .

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Reference Sheet 1
MALE SEXUAL SYSTEM 8 7 8 OJ 7 .£l"00\.....• ;:; ::>0\~ <Il '"~IQ)I"->. ~cru::>s ~ 6 5 bladder penis prostate gland 4 scrotum seminal vesicle testicle urethra vas deferens FEMALE SEXUAL SYSTEM 2 1 8 " \ 5 ... - ... j 4 labia \ ""\ bladderFallopian"k. "'"f"";".'''¥'&.tube\'WIT / I cervixt r r' \ \ clitorisurethrauterus 7 \ ~~ ;~f4f~ ~:iJ 3 ovaryvagina / ~ 2 / \ \\"- 9 6 adapted from F.L.A.S.H. Reproductive System Reference Sheet 3: GLOSSARY Anus – The opening in the buttocks from which bowel movements come when a person goes to the bathroom. It is part of the digestive system; it gets rid of body wastes. Buttocks – The medical word for a person’s “bottom” or “rear end.” Cervix – The opening of the uterus into the vagina. Circumcision – An operation to remove the foreskin from the penis. Cowper’s Glands – Glands on either side of the urethra that make a discharge which lines the urethra when a man gets an erection, making it less acid-like to protect the sperm. Clitoris – The part of the female genitals that’s full of nerves and becomes erect. It has a glans and a shaft like the penis, but only its glans is on the out side of the body, and it’s much smaller. Discharge – Liquid. Urine and semen are kinds of discharge, but the word is usually used to describe either the normal wetness of the vagina or the abnormal wetness that may come from an infection in the penis or vagina. Duct – Tube, the fallopian tubes may be called oviducts, because they are the path for an ovum.
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The Role of Jelly Coats in Sperm-Egg Encounters, Fertilization Success, and Selection on Egg Size in Broadcast Spawners
vol. 157, no. 6 the american naturalist june 2001 The Role of Jelly Coats in Sperm-Egg Encounters, Fertilization Success, and Selection on Egg Size in Broadcast Spawners Gregory S. Farley* and Don R. Levitan† Department of Biological Science, Florida State University, 1996a, 1998b; Coma and Lasker 1997). The proposed mech- Tallahassee, Florida 32306-1100 anism generating this result is simply that larger egg targets are more likely to be struck by swimming sperm (Rothschild Submitted February 2, 2000; Accepted January 19, 2001 and Swann 1949, 1951; Vogel et al. 1982). This finding has generated the hypothesis that sperm availability can influ- ence the evolutionary trade-off between egg size and num- ber (Levitan 1993, 1996a, 1996b, 1998a, 1998b). However, abstract: Sperm limitation may be an important selective force the idea that fertilization kinetics might influence this trade- influencing gamete traits such as egg size. The relatively inexpensive off has been challenged because of the notion that extra- extracellular structures surrounding many marine invertebrate eggs might serve to enhance collision rates without the added cost of cellular structures or chemoattractants may increase sperm- increasing the egg cell. However, despite decades of research, the egg collisions yet may not represent as great a cost to effects of extracellular structures on fertilization have not been con- fecundity as the trade-off associated with increased egg size clusively documented. Here, using the sea urchin Lytechinus varie- (Podolsky and Strathmann 1996; Styan 1998). These con- gatus, we remove jelly coats from eggs, and we quantify sperm col- tradictory ideas have not been resolved because data de- lisions to eggs with jelly coats, eggs without jelly coats, and inert tailing the influence of extracellular materials on fertilization plastic beads.
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Fertilization Selection on Egg and Jelly-Coat Size in the Sand Dollar Dendraster Excentricus
Evolution, 55(12), 2001, pp. 2479±2483 FERTILIZATION SELECTION ON EGG AND JELLY-COAT SIZE IN THE SAND DOLLAR DENDRASTER EXCENTRICUS DON R. LEVITAN1,2 AND STACEY D. IRVINE2 1Department of Biological Science, Florida State University, Tallahassee, Florida 32306-1100 2Bam®eld Marine Station, Bam®eld, British Columbia VOR 1B0, Canada Abstract. Organisms with external fertilization are often sperm limited, and in echinoids, larger eggs have a higher probability of fertilization than smaller eggs. This difference is thought to be a result of the more frequent sperm- egg collisions experienced by larger targets. Here we report how two components of egg target size, the egg cell and jelly coat, contributed to fertilization success in a selection experiment. We used a cross-sectional analysis of correlated characters to estimate the selection gradients on egg and jelly-coat size in ®ve replicate male pairs of the sand dollar Dendraster excentricus. Results indicated that eggs with larger cells and jelly coats were preferentially fertilized under sperm limitation in the laboratory. The selection gradients were an average of 922% steeper for egg than for jelly- coat size. The standardized selection gradients for egg and jelly-coat size were similar. Our results suggest that fertilization selection can act on both egg-cell and jelly-coat size but that an increase in egg-cell volume is much more likely to increase fertilization success than an equal change in jelly-coat volume. The strengths of the selection gradients were inversely related to the correlation of egg traits across replicate egg clutches. This result suggests the importance of replication in studies of selection of correlated characters.
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Module 10: Meiosis and Gametogenesis
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Female and Male Gametogenesis 3 Nina Desai , Jennifer Ludgin , Rakesh Sharma , Raj Kumar Anirudh , and Ashok Agarwal
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ANATOMY- PHYSIOLOGY-REPRODUCTIVE SYSTEM - IN RESPONSE TO CONVID 19 APRIL 2, 2020 nd Dear students and parents, April 2 , 2020 Beginning two days prior to our last day at school I issued work packets to all students in all classed; the content of which was spanning a two-three week period. Now that our removal from school will continue to at least May 1st, I have provided the following work packets which will span the remainder of the year, should our crisis continue. The following folders are available: ANATOMY – PHYSIOLOGY 1. Packet – THE HUMAN REPRODUCATIVE AND ENDOCRINE SYSTEMS. 2. Packet- THE HUMAN NERVOUS SYSTEM 3. Packet handed our prior to our last day: THE HUMAN EXCRETORY SYSTEM ZOOLOGY 1. Packet- STUDY OF THE CRUSTACEANS 2. Packet- STUDY OF THE INSECTS 3. Packet- handed our prior to our last day- INTRODUCTION TO THE ARTRHROPODS- CLASSES MYRIAPODA AND ARACHNIDA AP BIOLOGY – as per the newly devised topics of study focus, structure of adapted test, test dates and supports provided as per the guidelines and policies of The College Board TO ALL STUDENTS! THESE PACKETS WILL BE GUIDED BY THE SAME PROCEDURES WE EMBRACED DURING FALL TECH WEEK WHERE YOU ARE RESPONSIBLE FOR THE WORK IN THE PACKETS- DELIVERED UPON YOUR RETURN TO SCHOOL OR AS PER UNFORESEEN CHANGES WHICH COME OUR WAY. COLLABORATION IS ENCOURAGED- SO STAY IN TOUCH AND DIG IN! YOUR PACKETS WILL BE A NOTEBOOK GRADE. EVENTUALLY YOU SHALL TAKE AN INDIVIDUAL TEST OF EACH PACKET = AN EXAM GRADE! SCHOOL IS OFF SITE BUT NOT SHUT DOWN SO PLEASE DO THE BODY OF WORK ASSIGNED IN THE PACKETS PROVIDED.
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The Egg and the Sperm: How Science Has Constructed a Romance Based on Stereotypical Male- Female Roles Author(S): Emily Martin Reviewed Work(S): Source: Signs, Vol
The Egg and the Sperm: How Science Has Constructed a Romance Based on Stereotypical Male- Female Roles Author(s): Emily Martin Reviewed work(s): Source: Signs, Vol. 16, No. 3 (Spring, 1991), pp. 485-501 Published by: The University of Chicago Press Stable URL: http://www.jstor.org/stable/3174586 . Accessed: 06/04/2012 21:00 Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at . http://www.jstor.org/page/info/about/policies/terms.jsp JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. The University of Chicago Press is collaborating with JSTOR to digitize, preserve and extend access to Signs. http://www.jstor.org THE EGG AND THE SPERM:HOW SCIENCEHAS CONSTRUCTED A ROMANCEBASED ON STEREOTYPICAL MALE-FEMALEROLES EMILYMARTIN The theory of the human body is always a part of a world- picture.... The theory of the human body is always a part of a fantasy. [JAMESHILLMAN, The Myth of Analysis]' As an anthropologist, I am intrigued by the possibility that culture shapes how biological scientists describe what they discover about the naturalworld. If this were so, we would be learning about more than the natural world in high school biology class; we would be learning about cultural beliefs and practices as if they were part of nature.
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