Exam 1 ID#: October 4, 2007

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1 Biology 4361 Name: KEY Exam 1 ID#: October 4, 2007 Multiple choice (one point each) (1-25) 1. The process of cells forming tissues and organs is called a. morphogenesis. b. differentiation. c. allometry. d. embryogenesis. 2. The theory of most easily explained hybrid traits a. epigenesis. b. morphogenesis. c. dysmorphogenesis. d. preformation. 3. The germ line concept suggests that a. somatic cells are not represented in the next generation. b. primordial germ cells form a separate line from somatic cells. c. both a and b d. neither a nor b 4. Tracking one cell or group of cells through development is called a. phylogenetic screening. b. heterochronic isolation. c. fate mapping. d. lineage tracing. 5. Mesoderm generally forms a. skin and brain b. hair, scales, feathers c. central nervous system d. heart, bones, muscles 6. Transplantation of tissue from an embryo to a different location in another embryo is called: a. heterotopic b. heterochronic c. homeotopic d. homochronic 7. In female mammals, meiosis results in a. one oocyte. b. one oocyte and one polar body. c. one oocyte and two polar bodies. d. one oocyte and three polar bodies. 1

2 8. The first observable cellular activity in the oocyte after fertilization is a. polar body formation b. mitosis c. cytoplasmic rearrangement d. nuclear breakdown 9. Characteristics of gastrulation vary among different species, but is common among all. a. a movement of cells from the outside to the inside of the embryo b. movement of cells or cell layers along each other c. formation of new cell-to-cell relationships 10. Which one is the diploblast? a. sponge. b. earthworm. c. reptile. d. jellyfish. 11. If a cell from an embryo differentiates when placed in culture, but that differentiation can be reversed, that cell is considered a. specified by not determined. b. determined but not specified. c. both specified and determined A region of the Drosophila egg that contains equal amounts of nanos and bicoid genes will probably form a. antenna b. head c. abdomen d. tail 13. If an embryo develops normally after removal of some blastomeres, it is probably exhibiting a. b. deliberative specification c. compensatory adjustments. d. regulative development. 14. Cadherin binds to a. calcium. b. cadherin. c. catenin. 15. In organisms with autonomous specification, what vital information is carried by proteins and genes in the egg cytoplasm? a. age of the embryo. 2

3 b. position in the embryo. c. sex of the embryo. d. external environmental conditions. 16. Which of the following can be used to insert DNA into a cell? a. cold shock b. electricity c. UV radiation 17. RNA-interference techniques are used to a. block transcription b. block translation c. both a and b d. neither a nor b 18. The successful serial nuclear transfer experiments showed that advanced blastomeres could a. reverse their specification. b. be reprogrammed. c. return to a pluripotent state. 19. Embryonic cells changing fates to compensate for cells that have been removed from the embryo demonstrate a. regulative development. b. unregulated development. c. variable development. d. invariant development. 20. Methylation histones. a. stabilizes b. destabilizes c. has no effect on the stability of 21. A weak promoter a. is a protein that will not bind RNA polymerase II strongly. b. is a protein that binds RNA polymerase II strongly but inhibits transcription. c. generally will not allow transcription. d. generally has a low transcription rate. 22. Enhancers that inhibit transcription are referred to as a. repressors. b. de-enhancers. c. silencers. 3

4 23. The Lyon hypothesis states that in somatic cells containing two X chromosomes, one will be inactivated and that. a. The inactivation of the paternal or maternal X is random. b. The process is reversible, but only during cell division. c. The inactivation occurs at the two or four-cell stage of development Vertebrate nrnas contain a cap consisting of. a. 3', a methylated GTP in reverse orientation b. 3', poly-adenosine c. 5', a methylated GTP in reverse orientation d. 5', poly-adenosine 25. Transcription factors share what common features? a. all activate transcription b. all contain trans-activation sites c. all act alone d. all bind RNA True / False (1 point each) 26. Cloning technologies depend on genomic equivalence. T/F 27. The term blast refers to cells that participate in destruction of old cells and tissue. T/F 28. Homologous structures in different organisms might not have the same function. T/F 29. RNA transcription in Drosophila polytene chromosomes is tightly regulated by DNA methylation. T/F 30. TFIID, TFIIB, and TFIIA must bind to the promoter before RNA polymerase II can bind. T/F 31. Morpholino-antisense oligomers differ from normal antisense RNA in that they degrade quickly. T/F 32. Cellular RNA interference mechanisms probably evolved in response to RNA viruses. T/F 33. Cleavage in most insects occurs directly after nuclear division. T/F 34. Mammalian embryonic stem cells are considered totipotent. T/F 35. Dictyostelium transection experiments demonstrate mosaic development. T/F Matching (1 point each) 36. transcription factor _45_ enhancer 37. autonomous development _44_ cloning 38. stomatodeum _41_ RNAi 4

5 39. neural tube _39_ organogenesis 40. mesoderm _38_ mouth 41. knockdown _43_ X chromosome 42. environmental signals _42_ sex determination 43. dosage compensation _36_ basic helix-loop-helix 44. nuclear transfer _37_ mosaic 45. cis-acting _40_ gastrulation Short Answer. (5 points each; answer any 5) 46. Explain the statement Organisms don t have life cycles, they are life cycles. 47. Describe how a morphogen gradient could indicate positional identity in an embryo. 48. When calcium is removed from the media, embryos fall apart. Why? 49. Transgenes often contain an antibiotic resistance gene in addition to the gene of interest. Why? 50. Explain the statement Enhancers are modular and combinatorial. 51. List two transcription factor domains and explain their function. 52. Describe how unequal distribution of bicoid and nanos mrnas in Drosophila eggs result positional information for individual blastomeres. Short Essay. You wish to know whether the cells in a certain region of a developing embryo are determined. Describe an experiment that would answer that question. Many insects exhibit a phenomenon called seasonal polyphenism. Define this term and describe in general terms how it might occur and what the results might be in an organism (you describe seasonal polyphenism in a real organism or in a generic example of your own). A new species of organism was found in the deep sea, but scientists were unable to classify the adult forms into one of the known phyla. A developmental biology student observed that one of von Baer s laws may help us out here. What general principle was the student referring to, and how could it be used to help classify the organism? 5