Exam 1-08 - name Biology of Human Reproduction IPHY 4470...

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________________________________ Biology of Human Reproduction, IPHY 4470 Fall 2008, Exam 1 Choose one best answer for each question. 1. A molecule acts as a paracrine signal when a. the molecule travels to its target through the bloodstream. b. the cell releasing the molecule also responds to the molecular signal. c. it is released by one organism and has its effect on another organism. d. only one cell type is responsive to the molecular signal. e. cells adjacent to the releasing cell respond to the molecular signal. 2. Which of the following statements about steroid hormones is false ? a. Steroid hormones are derived from cholesterol. b. Steroid hormones are degraded when clathrin-coated pits become endosomes. c. Steroid hormones form complexes with proteins to travel through bloodstream. d. Steroid hormones are lipid soluble. e. none of the above 3. A “second messenger” in endocrine signaling a. attaches to a membrane-bound receptor. b. changes the 3-dimensional conformation of the “first messenger”. c. relays a molecular message from a transmitting cell to a receiving cell. d. transmits the endocrine signal into the cell’s cytoplasm. e. results from the translation of the first messenger gene. 4. A single polypeptide hormone can produce a relatively large cellular response because a. the receiving cell responds by producing many copies of the polypeptide hormone. b. the hormone binds permanently to the receptor, producing a long-lasting signal. c. the hormone/receptor complex binds to DNA, activating transcription. d. binding of the hormone sets off an enzyme cascade that amplifies the signal. e. all of the above 5. Inactivation of the G protein/adenylate cyclase system in a cell would halt the cell’s response to a. GnRH b. estrone c. androstenedione d. progesterone e. all of the above 6. Which of the following is characteristic of both steroid and protein/polypeptide hormones? a. The receptor has a transmembrane domain. b. Hormone binding activates cyclic AMP. c. The receptor is a protein. d. The activated receptor acts as a transcription factor. e. The biological effect is increased in the presence of an antagonist.
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This note was uploaded on 10/08/2008 for the course IPHY 4470 taught by Professor Lopez during the Fall '08 term at Colorado.

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Exam 1-08 - name Biology of Human Reproduction IPHY 4470...

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