NPB 128 Final Study Questions Chang

NPB 128 Final Study Questions Chang - 1. Have any common...

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1. Have any common hormones been found in both vertebrates and invertebrate? a. Insulin? 2. A common experimental procedure conducted by crustacean endocrinologists is to remove the eystalks of higher crustaceans. Describe and explain the possible outcome(s) of such an experiment. Mention in your answer(s) the status of the experimental animal (e.g. sex, maturity, etc.) and how this might affect the outcome of the experiment. a. The eyestalk of the crustacean contains the retina which contains the X-organ, which contains neurosecretory neurons. b. Produce and secrete peptide hormones and interact with other nerve cells c. Contain the sinus gland d. Produces and secretes Molt-inhibiting hormone. e. MIH inhibits the Y-organ that makes the molting hormone ecdysone 20E f. 20E allows the molt cycle to occur @ 75days, begins to rise (premolt) g. Drops to ~0 at actual molt h. Removing the eyestalk removes MIH’s inhibition on ecdysone, and therefore 20E is in higher levels. The molt cycle occurs more quickly and more molts occur at a faster frequency. i. Eyestalk also inhibits the mandibular organ which produces methyl farnesoate, which INDUCES the y-organ. MF. j. Ecdysone is also invested in the offspring, and fluctuates during pregnancy, embryogenesis. 3. Compare and contrast the endocrine regulation of reproduction in a crustacean, an insect, and a vertebrate. a. Crustaceans: Sex genotype determined by chromosomes, XX, XY. However, sex phenotype and fertility is determined by the presence of an androgenic gland AG. Presence of the androgenic gland produces primary male characteristics/organs, secondary male morphology/ characteristics, and tertiary male behavior. Absence creates a female with these organs/morphology/behavior. Two XX can mate if one of those have an AG, two XY can mate if one lacks an AG. i. What are those cup pictures? Parasitic castration, hermaphroditic protandric. *** ii. Vitelligen is decreased with androgenic hormone. iii. Maternal investment of yolk and hormones iv. Insulin-like hormone also found in the AG
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b. Insects: 20E is transferred from the male to the female during mating. Virgin males have the high levels whereas virgin females have low levels. Allohormones. i. 20E serves as a gonadotropin and helps with the egg/offspring evelopment c. JH is used as the sex hormones in cockroaches. It acts as a steroid hormone and binds to DNA to transcribe the genes for yolk. i.
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This note was uploaded on 03/28/2010 for the course NPB NPB 128 taught by Professor Furlow/chang during the Winter '10 term at UC Davis.

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NPB 128 Final Study Questions Chang - 1. Have any common...

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