Exam 1 ID#: October 1, 2006

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1 Biology 4361 Name: Exam 1 ID#: October 1, 2006 Multiple choice (one point each) 1. The formation of new structures in chick embryogenesis is an example of a. teratology. b. epigenesis. c. hybridization. d. preformation. 2. A term referring to something that makes up a formative unit of living matter is a. blast. b. germ. c. derm. d. medial. 3. Which of the following is not included in von Baer s laws: a. General features appear earlier than specialized features. b. Specialized features always develop from more general features. c. Developing embryos pass through the adult stages of lower animals. d. None of the above; they are all included in von Baer s laws. 4. In general, the mesoderm forms a. muscle, connective tissue, bones. b. epidermis of the skin, central nervous system. c. epithelium of the digestive tract. 5. Transplantation experiments involving removal of tissue and placement in another location are called a. heterospecific b. homospecific c. heterochronic 6. The process by which embryonic cells to form distinct cell layers is called a. cleavage. b. histogenesis. c. organogenesis. d. gastrulation. 7. The meiotic stage during which chromosomes undergo homologous recombination is called a. prophase I b. metaphase I c. anaphase I d. metaphase II 1

2 9. Prior to the first cleavage, the fertilized vertebrate egg can be expected to undergo a. expulsion of the polar body. b. completion of meiosis. c. cytoplasmic rearrangement. 8. The chemotactic signal used by Dictyostelium for aggregation is a. adenosine monophosphate b. cyclic adenosine monophosphate c. adenosine triphosphate d. cyclic adenosine triphosphate 10. Cutting the Dictyostelium pseudoplasmodium in half eventually results in two fruiting bodies. This result demonstrates a. variant development b. invariant development c. linear development d. regulative development 11. Sea urchin cleavage is described as a. holoblastic bilateral. b. meroblastic bilateral. c. holoblastic radial. d. meroblastic radial. 12. In sea urchin eggs, the first, second, and third cleavages are a. meridional, equatorial, meridional. b. equatorial, equatorial, meridional. c. meridional, meridional, equatorial. d. equatorial, meridional, meridional. 13. Echinoderms are, therefore the mouth is the opening formed during development. a. protostomes, first b. protostomes, second c. deuterostomes, first d. deuterostomes, second 14. Organisms that can respond to environmental changes with changes in color or form demonstrate a. polyploidy. b. pluriploidy. c. seasonality. d. polyphenism. 2

3 15. Developing at 28 C, most alligators would be expected to be a. male. b. female. c. cold. d. angry. 16. If you transplanted embryonic cells from the leg area to the back area, but they still developed into leg structures, the original cells must have been a. determined. b. determined, but not specified. c. specified, but not determined. 17. Most invertebrates undergo a. autonomous specification. b. mosaic development. c. invariant cleavage. 18. In most invertebrates, loss of an individual blastomere results in a. loss of structures that would derive from that blastomere. b. no loss of structures, since other blastomeres will fill in for the loss. c. partial loss of structures, since some blastomeres are only pluripotent. d. loss of structures early, but compensation by other blastomeres in later stages. 19. After cellularization, Drosophila embryos undergo a. invariant specification. b. conditional specification. c. mosaic development. 20. The strength of cadherin binding can be controlled by a. catenin binding. b. phosphorylation. c. calcium ions. 21. The principle of genomic equivalence states that a. DNAs of all differentiated cells are identical. b. all differentiated cells originate as pluripotent stem cells. c. with few exceptions (gametes, differentiated red blood cells) all nuclei carry a diploid chromosome number throughout their lives. 3

4 22. Antisense RNA inhibits expression through a. complementary binding. b. the RISC complex. c. the Dicer nuclease. 23. A transcription factor that increased the amount of histone acetyltransferase activity at the promoter would probably a. repress transcription. b. activate transcription. c. allow inhibition. d. have no effect on transcription. 24. Histone methylation transcription. DNA methylation transcription. a. increases, decreases b. increases, increases c. decreases, increases d. decreases, decreases 25. Enhancers affect transcription by a. remodeling chromatin to expose the promoter. b. making RNA polymerase II more efficient. c. preventing repressors from binding to the promoter. True / False (1 point each) 26. The process of forming cells and tissues is called morphogenesis. 27. Cleavage can be described as cell division followed by cell growth. 28. Epithelial cells are often found in sheets with many intracellular connections. 29. A syncytium is a cell that undergoes nuclear division without cell division. 30. In embryos with conditional specification, cell rearrangements take place after specification. 31. Mammalian embryonic stem cells are produced by culturing the trophoblast. 32. Morpholino-antisense oligomers degrade quickly, and are used to study transient events. 33. About half of all vertebrate genes are regulated by enhancers. 34. Enhancer sequences are capable of binding multiple proteins. 35. Some enhancers repress transcription. 4

5 Matching (1 point each) Make the best connection. 36. basic helix-loop-helix a. actin 37. catenin b. alkaline phosphatase label 38. cellular blastoderm c. Drosophila 39. electroporation d. homologous recombination 40. gene knockouts e. morphogen gradient 41. in situ hybridization f. mycosporine-like amino acids 42. oligonucleotide primers g. retroviruses 43. RNAi h. RT-PCR 44. source/sink i. transcription factor 45. UV radiation j. transgenic production Short Answer (5 points each; answer any 5) 46. Describe the structure of reporter genes. 47. Enhancers are modular and act combinatorial. Explain what this means. 48. List the domains common to all transcription factors and describe their functions. 49. Calico cats are always female. Why? 50. Mammalian cloning (somatic cell nuclear transfer) is not possible in all species and the technique is highly inefficient in species where it has been successful. What is the most likely cause for the overall difficulty in mammalian cloning? 51. When making chimeric mice, transgenic embryonic stem cells are produced that contain a gene for antibiotic resistance. Why is this gene included? 52. What are the general characteristics of pluripotent stem cells? 5

6 Short Essay. 35 points total. Answer Question 53 (15 points), and two out of remaining questions (54-56, 10 points each). Use the space provided or the back of the sheet for text and diagrams, if needed. 53. How might an environmental signal, such as light, temperature, or a natural or man-made chemical change the course of development for an organism? Using any information that we ve covered in the class thus far, create a developmental situation in which some signal from the environment changes the course of development in a given organism. List the organism and signal, and describe the pathway by which the signal is received by the organism and ends up producing the developmental change. None of the signals or mechanisms you choose have to be from real situations (although you can use actual phenomena if you like), but the signals and mechanisms have to be plausible, i.e. they should demonstrate your knowledge of actual mechanisms. 54. Outline the procedure for producing chimeric mice. 6

7 55. Describe the Dictyostelium life cycle. 56. Describe the process of early development in Drosophila, between fertilization and the cellular blastoderm stage. BONUS (2 points) - Occasionally, a male calico cat appears. What is the probable explanation for this unusual phenomenon? EXTRA BONUS (1 point) - The 2006 Nobel Prize for physiology or medicine was recently awarded to Andrew Fire and Craig Mello for what discovery? 7