Download October 4, 2007

Biology 4361
Exam 1
October 4, 2007
Name:___KEY______________
ID#: ____________________
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.
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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
d. all of the above.
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.
d. none of the above.
12. 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.
d. all of the above.
15. In organisms with autonomous specification, what vital information is carried by proteins and
genes in the egg cytoplasm?
a. age of the embryo.
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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
d. none of the above
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.
d. all of the above.
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
d. none of the above
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.
d. none of the above
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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.
d. none of the above.
24. 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
37. autonomous development
38. stomatodeum
_45_ enhancer
_44_ cloning
_41_ RNAi
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39. neural tube
40. mesoderm
41. knockdown
42. environmental signals
43. dosage compensation
44. nuclear transfer
45. cis-acting
_39_ organogenesis
_38_ mouth
_43_ X chromosome
_42_ sex determination
_36_ basic helix-loop-helix
_37_ mosaic
_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?
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