Oct. 30, 1997
                                   S. Shostak
                      Foundations of Biological Science II
                                Second Hour Exam

Instructions:
Be sure to use a #2 pencil on your answer sheet. Print your last and first name
and your social security number and fill the circles below. When you are finished,
sign your answer sheet on the margin, and place it upon the correct, color-coded
pile. You may keep your exam and take a copy of the answers (also color coded).
Please show your student identification when leaving the room.
                 _____________________________________________

 1. Steroid hormones produce their effects in cells by
    a. promoting the formation of looped domains in certain regions of
       DNA.
    b. activating translation of certain mRNAs.
    c. promoting the degradation of specific mRNAs.
    d. activating key enzymes in metabolic pathways.
    e. promoting transcription of certain regions of DNA.

 2. If one were to observe the activity of methylated DNA, it would be
    expected that it would
    a. be unwinding in preparation for protein synthesis.
    b. induce protein synthesis by not allowing repressors to bind with
       it.
    c. have turned off or slowed down the process of transcription.
    d. be replicating.
    e. become very active in translation.

 3. Muscle cells and nerve cells in one kind of animal owe their
    differences in structure to
    a. expressing different genes.
    b. having different genes.
    c. having different chromosomes.
    d. using different genetic codes.
    e. having unique ribosomes.

 4. The gene that stimulates tumorogenesis in Burkitt's lymphoma is
    expressed when it is moved to chromosome 14 from chromosome 8. This
    is an example of gene expression regulated by
    a. gene amplification.
    b. point mutations.
    c. diffusible factors.
    d. translocation.
    e. steroid hormones.

 5. The processing of the RNA transcript involves
         1. the removal of introns and the splicing together of exons.
         2. the removal of exons and the splicing together of introns.
         3. the addition of a guanine cap and a poly-A tail.
         4. the attachment of introns to ribosomal RNA.
    a. 1
    b. 2
    c. 4
    d. 3
    e. Both 1 and 3 are correct.

 6. Chromosome puffs are thought to represent chromosomal regions where
    a. regulatory genes are located.
    b. genes are inactivated by repressor proteins.
    c. genes are especially active in transcription.
    d. genes have been damaged.
    e. hormones are produced.

 7. In which of the following cell types would you observe gene
    amplification?
    a. red blood cells that produce hemoglobin
    b. a developing amphibian ovum
    c. white blood cells that produce antibodies
    d. cells that produce silk in silk worms
    e. cells of a developing fetus

 8. Which of the following is an example of transcriptional control of
    gene expression?
    a. Transcription factors bind to enhancer and promoter region.
    b. mRNA exists for a specific time before it is degraded.
    c. RNA processing occurs before mRNA exits the nucleus.
    d. There is an amplification of genes for rRNA.
    e. mRNA that is stored in the cytoplasm and needs a control signal
       to initiate translation.

 9. What is meant by the word metastasis?
    a. the activation of an oncogene
    b. the development of contact inhibition
    c. a mutation that causes cancer
    d. the spread of cancer cells from their site of origin
    e. the transformation of a normal cell to a cancer cell

10. Which of the following is true of gene regulation in BOTH
    prokaryotes and eukaryotes?
    a. DNA binding proteins interact with other proteins and
       environmental factors to control gene expression.
    b. 10-25% of the cell's DNA forms "satellite" DNA, thus limiting the
       amount of DNA available for transcription.
    c. Noncoding sequences are transcribed into RNA from the DNA, thus
       slowing down the rate at which the genes are transcribed.
    d. Heterochromatin remains coiled, thus preventing its
       transcription.
    e. Nucleosomes regulate gene expression by preventing
       transcriptional factors from associating with DNA.

                 ---------------------------------------
    Refer to the techniques, tools, or substances given below to answer
    the following question(s). Choices may be used once, more than once,
    or not at all.
 
         1. restriction enzymes
         2. gene cloning
         3. DNA ligase
         4. gel electrophoresis
         5. reverse transcriptase

11. Separates molecules by movement due to size and electrical charge.
    a. 5
    b. 1
    c. 4
    d. 3
    e. 2

12. Produces many copies of a gene for basic research or for large-
    scale production of a gene product.
    a. 3
    b. 2
    c. 1
    d. 4
    e. 5

13. Seals the sticky ends of restriction fragments to make recombinant
    DNA.
    a. 1
    b. 4
    c. 5
    d. 2
    e. 3

14. PCR could be used to amplify DNA from which of the following?
    a. a virus
    b. a fossil
    c. a fetal cell and a virus
    d. a fossil, a fetal cell, and a virus
    e. a fetal cell

15. What is a cloning vector?
    a. an agent, such as a plasmid, used to transfer DNA from an in
       vitro solution into a living cell
    b. a DNA probe used to locate a particular gene in the genome
    c. the enzyme that cuts DNA into restriction fragments
    d. the sticky end of a DNA fragment
    e. the laboratory apparatus used to clone genes

16. The polymerase chain reaction is important because it allows us to
    a. insert eukaryotic genes into prokaryotic plasmids.
    b. make DNA from RNA transcripts.
    c. make many copies of DNA.
    d. incorporate genes into viruses.
    e. insert regulatory sequences into eukaryotic genes.

                 ---------------------------------------
    Use the choices shown below to answer the following question(s).
    Each choice may be used once, more than once, or not at all.
 
         1. restriction endonuclease
         2. DNA ligase
         3. reverse transcriptase
         4. RNA polymerase
         5. DNA polymerase

17. Which enzyme is used to make multiple copies of genes in the
    polymerase chain reaction (PCR)?
    a. 3
    b. 4
    c. 2
    d. 1
    e. 5

18. Which enzyme is used to make complementary DNA (cDNA)?
    a. 5
    b. 3
    c. 2
    d. 1
    e. 4

19. Which enzyme is used to produce RFLPs?
    a. 1
    b. 2
    c. 4
    d. 5
    e. 3

20. What did Charles Darwin publish in 1859?
    a. The Growth of Biological Thought
    b. On the Nature of Things
    c. On the Origin of Species by Means of Natural Selection
    d. Vestiges of Creation
    e. Philosophie Zoologique

21. When single-stranded DNA from a human is mixed with single-stranded
    DNA from a chimpanzee, we find that about 99% of the DNA is
    homologous. This can be taken as evidence that
    a. all organisms have similar DNA.
    b. humans and chimpanzees originated in similar environments.
    c. chimpanzees evolved from humans.
    d. humans and chimpanzees are closely related.
    e. humans evolved from chimpanzees.

22. The effect of natural selection in the case of the English peppered
    moth, Biston betularia, illustrates that the advantage of inherited
    traits depends on the
    a. presence of cytochrome c.
    b. environment.
    c. principle of common descent.
    d. presence of homologies among moths.
    e. intensity of melanin.

23. One finds that organisms on islands are different from, but closely
    related to, similar forms found on the nearest continent. This is
    taken as evidence that
    a. the island forms and mainland forms are converging.
    b. island forms and mainland forms share the same gene pool.
    c. common environments are inhabited by the same organisms.
    d. the islands were originally part of the continent.
    e. island forms and mainland forms descended from common ancestors.

24. Which of the following has provided an abundance of evidence that
    the Earth has had a succession of flora and fauna?
    a. the fossil record
    b. creationism
    c. population genetics
    d. natural selection
    e. catastrophism

25. Of the following anatomical structures, which is homologous to the
    wing of a bat?
    a. the tail of a kangaroo
    b. the arm of a human
    c. the tail fin of a fish
    d. the wing of a butterfly
    e. the dorsal fin of a shark

26. Which of the following represents an idea Darwin took from the
    writings of Thomas Malthus?
    a. The environment is responsible for natural selection.
    b. Populations tend to increase at a rate greater than their food
       supply.
    c. The Earth is more than 10,000 years old.
    d. All species are fixed in the form in which they are created.
    e. The Earth changed over the years through a series of catastrophic
       upheavals.

27. Darwin was able to formulate his theory of evolution based on
    several facts. Which of the following facts was unavailable to
    Darwin in the mid-nineteenth century?
    a. Individual organisms in a population are not alike.
    b. Characteristics are inherited as genes on chromosomes.
    c. Natural resources are limited.
    d. Most populations are stable in size.
    e. All populations have the potential to increase.

28. The decrease in the size of plants on the slopes of mountains as
    altitudes increase is an example of
    a. speciation.
    b. relative fitness.
    c. a bottleneck.
    d. a cline.
    e. genetic drift.

29. When we say that one organism has a greater fitness than another
    organism, we specifically mean that it
    a. utilizes resources more efficiently than other species occupying
       similar niches.
    b. competes for resources more successfully than others of its
       species.
    c. leaves more viable offspring than others of its species.
    d. lives longer than others of its species.
    e. mates more frequently than others of its species.

30. Natural selection is most closely related to
    a. diploidy.
    b. genetic drift.
    c. assortive mating.
    d. gene flow.
    e. differential reproductive success.

31. In a Hardy-Weinberg population, the frequency of the "a" allele is
    0.4. What is the frequency of individuals with "Aa" genotype?
    a. Cannot tell from the information provided.
    b. 0.60
    c. 0.48
    d. 0.16
    e. 0.20

32. Most copies of harmful recessive alleles in a population are carried
    by individuals that are
    a. homozygous for the allele.
    b. diploid.
    c. heterozygous for the allele.
    d. afflicted with the disorder caused by the allele.
    e. polymorphic.

33. You sample a population of butterflies and find that 42% are
    heterozygous for a particular gene. What would be the frequency of
    the recessive allele in this population?
    a. 0.09
    b. 0.3
    c. 0.7
    d. 0.49
    e. Allele frequency cannot be estimated from this information.

34. A change in the frequencies of alleles in the gene pool of a small
    population arising from chance events is called
    a. genetic drift.
    b. gene flow.
    c. selection.
    d. mutation pressure.
    e. differential reproduction.

35. Which of the following is likely to have been produced by sexual
    selection?
    a. the ability of desert animals to concentrate their urine
    b. different sizes of male and female pine cones
    c. bright colors of female flowers
    d. camouflage coloration in animals
    e. a male lion's mane

36. What term best describes a change in allelic frequencies due to an
    influx of new members into a population?
    a. gene flow
    b. genetic drift
    c. convergent evolution
    d. founder effect
    e. selection

37. A characteristic of allopatric speciation is
    a. geographic isolation.
    b. the appearance of new species in the midst of old ones.
    c. large populations.
    d. asexually reproducing populations.
    e. artificial selection.

38. Plant species A has a diploid number of 28. Plant species B has a
    diploid number of 14. A new, sexually reproducing species C arises
    as an allopolyploid from hybridization of A and B. The diploid
    number of C would probably be
    a. 28
    b. 42
    c. 21
    d. 14
    e. 63

                 ---------------------------------------
    Use the following options to answer the question(s). For each
    description of reproductive isolation, select the option which best
    describes it. Options may be used once, more than once, or not at
    all.
              1. gametic
              2. temporal
              3. behavioral
              4. habitat
              5. mechanical

39. Mating fruit flies recognize the appearance, odor, tapping motions,
    and sounds of members of their own species, but not of other
    species.
    a. 1
    b. 5
    c. 2
    d. 4
    e. 3

40. Two species of pine shed their pollen at different times.
    a. 3
    b. 2
    c. 5
    d. 1
    e. 4

41. Two species of garter snakes living in the same region, but one
    lives in water, and the other lives on land.
    a. 5
    b. 1
    c. 3
    d. 2
    e. 4

42. Which of the following statements are consistent with the punctuated
    equilibrium interpretation of speciation?
    a. Evolution proceeds at a slow, steady pace.
    b. There is an equilibrium between living and extinct species.
    c. Large populations evolve more quickly than small ones.
    d. Long periods of minor change are interrupted by short bursts of
       significant change.
    e. Rapid speciation is caused by population explosions.

43. The process of a new species arising within the range of the parent
    populations is termed
    a. parapatric speciation.
    b. allopatric speciation.
    c. adaptive radiation.
    d. semispeciation.
    e. sympatric speciation.

                 ---------------------------------------
    Refer to Figure 23.1 to answer the following question(s).  (not available)
 

44. A common ancestor for species C and E could be at position number
    a. 5.
    b. 1.
    c. 3.
    d. 2.
    e. 4.

45. The most closely related species are
    a. B and D.
    b. D and E.
    c. C and B.
    d. E and A.
    e. A and B.

46. Which of the following can be used to determine the absolute age of
    fossils?
    a. sedimentary strata
    b. the half-life of isotopes
    c. the "DNA clock"
    d. index fossils
    e. cladistics

47. Which of the following can best be explained by continental drift?
    a. the scarcity of placental mammals in Australia
    b. the relative age of fossils
    c. the Chicxulub crater
    d. the survival of Purgatorius
    e. polyphyletic taxa

48. A major evolutionary episode that corresponded in time most closely
    with the formation of Pangaea was the
    a. Cambrian explosion.
    b. Cretaceous extinctions.
    c. Permian extinctions.
    d. origin of humans.
    e. Pleistocene ice ages.

49. The half-life of carbon-14 is 5,600 years. A fossil that has
    one-eighth the normal proportion of carbon-14 to carbon-12 is
    probably
    a. 16,800 years old.
    b. 1,400 years old.
    c. 22,400 years old.
    d. 11,200 years old.
    e. 2,800 years old.

50. The anomalous layer of iridium clay that has figured so prominently
    in the asteroid theory is located at which geological boundary?
    a. Mesozoic-Cenozoic
    b. North American-Pacific plates
    c. Paleozoic-Mesozoic
    d. Laurasia-Gondwana
    e. Precambrian-Paleozoic

                 _____________________________________________