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Unformatted text preview: Name: ______________________________________ Student ID:________________________ Page 1 Zoology 470 - Exam #1 – 2006 This exam has 5 pages and a total of 50 points. You will have 90 minutes to complete it. Answer all short answer questions as briefly as possible. Make sure your name and ID number are on all pages. You will receive 1 point for doing so. 1. Provide concise definitions for each of the following ( 6 points ) a. RESACT: A peptide derived from egg jelly in sea urchins. RESACT acts as a chemoattractant for sperm. b. Sertoli cell: A cell type in the seminiferous tubules of the testis, Sertoli cells are connected to developing spermatids, and provide nutrients and metabolites to the spermatids via cytoplasmic bridges. c. acrosomal vesicle: A membrane-bound organelle immediately underneath the plasma membrane of sperm cells. The acrosomal vesicle fuses with the plasm membrane as part of the acrosome reaction, releasing digestive enzymes needed for sperm to penetrate extracellular materials on their way to the egg/oocyte surface. d. conditional specification: The process whereby cells acquire distinct fates as a result of environmental cues, such as inductive signals from nearby cells. e. azoospermia: Failure of male mammals (e.g., human men) to produce sperm cells. Often this is due to an obstruction in the vas deferens or testicles (in which case it is called obstructive azoospermia). f. morphogenesis: The process of building the embryo. Morphogenesis involves changes in cell movement and adhesion that shape the body. 2. Reproduction in humans is regulated by hormones. A major pharmaceutical company has used this fact to develop commercial products. a. One way to produce "superovulation" (i.e., production of more than one oocyte at a time) for in vitro fertilization uses an estrogen-blocking drug called Clomiphene. Based on your knowledge of hormonal signaling during ovulation, why would this promote ovulation? ( 2 points ) At a particular point in the ovulatory cycle, estrogen exerts negative feedback omn the hypothalamus (and hence, indirectly, on the anterior pituitary). By blocking estrogen, this inhibition is removed, cause multiple follicles to mature simultaneously. b. One product on the market is targeted towards women having difficulty becoming pregnant. It detects pituitary hormones in urine that correlate with the ovulatory cycle. What hormones should this kit test for? ( 1 point ) FSH & LH Name: ______________________________________ Student ID:________________________ Page 2 2. (cont) c. A third product produced by this company is a home pregnancy test that tests for successful conception (i.e., fertilization) within 7 days of the event. What hormone does this product test for? ( 1 point ) hCG d. RU486 interferes with the normal function of progesterone during early pregnancy. What tissue is the most important target of progesterone that is affected by the drug? ( 1 point ) The uterine lining (the cervix as well), causing sloughing ot he endometrium and explusion of...
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- Spring '08
- Genetics, sperm cells, Spermatozoon, sea urchin egg, sea urchin sperm