EXAM 3. BIOL.1406. FALL 2004
NAME_________________
1. Mutations are changes in the:
A) sugar-phosphate backbone of DNA
B) base-pairing rules for DNA
C) sequence of bases in DNA
D) sequence of sugars in DNA
2. In Griffith's experiments, what happened when heat-killed S-strain
pneumococcus were injected into a mouse along with live R-strain
pneumococcus?
A) DNA from the live R-strain was taken up by the heat-killed S-strain,
converting them to R-strain and killing the mouse.
B) DNA from the heat-killed S-strain was taken up by the live R-strain,
converting them to S-strain and killing the mouse.
C) Proteins released from the heat-killed S-strain killed the mouse.
D) RNA from the heat-killed S-strain was translated into proteins that killed
the mouse.
E) nothing
3. If amounts of bases in a DNA molecule are measured, we find
A) A = C and G = T.
B) A = G and C = T.
C) T = A and C = G.
D) no two bases would be equal in amount.
E) that all bases are equal in amount.
4. The DNA of a certain organism has guanine as 30% of its bases. What
percentage of its bases would be adenine?
A) 0%
B) 10%
C) 20%
D) 30%
E) 40%
5. Complementary base pairs are held together by
A) peptide bonds.
B) hydrogen bonds.
C) disulfide bonds.
D) covalent bonds.
E) ionic bonds.
6. For the DNA sequence GCCTAT in one polynucleotide chain, the sequence
found in the other polynucleotide chain is
A) CGGATA.
B) GCCATA.
C) CGGAUA.
D) ATTCGC.
E) GCCTAT.
7. Why did scientists at first think that DNA would be a poor candidate for the
hereditary material?
A) Griffith's experiments suggested protein was the hereditary material.
B) Studies showed that viruses lacking DNA passed genetic traits to the next
generation.
C) DNA was made of only four kinds of subunits.
D) The work of Franklin and Wilkins showed that DNA could not be the
hereditary material.
E) None of the above is correct.
8. Semiconservative DNA replication means
A) the old DNA is completely broken down.
B) the old DNA remains completely intact.
C) A pairs with T and G pairs with C.
D) only half of the DNA is replicated.
E) each new DNA molecule has half of the old one
9. Which of the following are NOT involved in the DNA replication process?
A) DNA helicase
B) DNA ligase
C) DNA replicase
D) DNA polymerase
E) All of the above are involved.
10. Which one of the following forms of damage to DNA is caused by ultraviolet
light?
A) Adjacent thymines on a strand become linked together.
B) The two strands become separated from each other.
C) The DNA becomes fragmented.
D) The DNA begins growing uncontrollably.
E) The DNA begins to decay from its two ends.
11. The sequence of nitrogen-containing bases on one strand of DNA most directly
determines the sequence of
A) fatty acids in a fat molecule.
B) amino acids in a protein molecule.
C) sugars in a polysaccharide molecule.
D) All of the above choices are correct.
E) bases in a protein molecule.
12. Which of these is found in RNA but NOT in DNA?
A) adenine
B) uracil
C) thymine
D) phosphate groups
E) none of theabove
13. The process of copying genetic information from DNA to RNA is called
A) translation.
B) transformation.
C) replication.
D) transcription.
E) polymerization.
14. Which of the following molecules functions to transfer information from the
nucleus to the cytoplasm?
A) DNA
B) mRNA
C) tRNA
D) proteins
E) lipids
15. What mRNA carries from the nucleus is
A) enzymes.
B) ribosomes.
C) information.
D) amino acids.
E) tRNA
16. If a tRNA molecule specialized for transfer of the amino acid valine has the
anticodon CAG, with what codon will it couple?
A) GAC
B) GTC
C) TUG
D) GUC
E) CAG
17. The process of converting the "message" of mRNA into a sequence of amino
acids is called
A) translation.
B) transcription.
C) activation.
D) replication.
E) repression.
18. The site of protein synthesis is the
A) smooth endoplasmic reticulum.
B) nucleus.
C) nucleolus.
D) ribosome.
E) eukaryotic chromosome
19. Each new amino acid is attached to the growing chain by
A) an ionic bond.
B) a physical bond.
C) hydrogen bonds.
D) an RNA bond.
E) a peptide bond.
20. Ribosomes are a collection of
A) small proteins that function in translation.
B) proteins and small RNAs that function in translation.
C) proteins and tRNAs that function in transcription.
D) proteins and mRNAs that function in translation.
E) mRNAs and tRNAs that function in translation.
21. A random change in a DNA nucleotide base sequence
A) has no influence on genetic variation.
B) is never expressed phenotypically.
C) constitutes a mutation.
D) is never beneficial to the organism.
E) will kill the cell when it occurs.
22. For a mutation to affect evolution, it must occur in
A) somatic cells.
B) prokaryotic cells.
C) diploid cells.
D) gametes.
E) eukaryotic cells.
23. Of the following types of mutations, which is considered the LEAST drastic?
A) insertion of one base
B) deletion of two bases
C) a neutral base substitution
D) a stop codon
E) a substitution of a hydrophilic amino acid for a hydrophobic one
24. Which point mutation would be most likely to have a catastrophic effect on the
functioning of a protein?
A) a base substitution
B) a base deletion near the start of the coding sequence
C) a base deletion near the end of the coding sequence
D) deletion of three bases near the start of the coding sequence
E) a base insertion near the end of the coding sequence
25. Which of the following is NOT a means of regulating gene expression?
A) regulating the life span of a protein
B) modifying proteins after they are synthesized
C) varying the rate at which messenger RNAs are translated
D) varying the rate at which messenger RNAs are transcribed
E) deleting genes from cells in which they are not needed
26. Calico cats are almost always female. This is because of
A) X-chromosome inactivation.
B) the lack of a Y chromosome in females.
C) activation of the calico gene by the female sex hormone estrogen.
D) the calico gene in males is inactivated by the sex hormone testosterone.
E) a mutation found on the X chromosome
27. RNA splicing is the
A) addition of introns to the mRNA.
B) deletion of introns from the mRNA.
C) addition of exons to the mRNA.
D) deletion of exons from the mRNA.
E) combination of two different chromosomes together
28. The incorrect theory that "organisms (such as giraffes) can modify their bodies
through use or disuse of parts, and that these modifications can be passed on to
their offspring" was formulated by
A) Hutton.
B) Darwin.
C) Aristotle.
D) Lamarck.
E) Lyell.
29. The theory of natural selection states that
A) all individuals live to reproduce in each generation.
B) only the largest and strongest survive.
C) random assortment of genes results in better characteristics in the
following generations.
D) the best adapted individuals survive and reproduce, contributing the most
genes to the next generation.
E) individuals that mutate in response to their environment will survive.
30. A change in the genetic makeup of a population is
A) natural selection.
B) uniformitarianism.
C) artificial selection.
D) evolution.
E) genetic drift.
31. Evidence which supports the theory of evolution is found in the studies of
A) comparative anatomy and embryology.
B) genetics and molecular biology
C) fossils.
D) artificial selection.
E) all of these
32. Which of the following is a basic requirement for natural selection to be an
effective evolutionary force?
A) mutation must occur frequently
B) individuals reproduce at a rapid rate
C) each population is limited to a small size
D) a population exhibits some genetic variability
E) all of the above
33. The fossil record indicates that over the last 50 million years the horse has
evolved in all of the following ways, except?
A) tooth structure
B) leg anatomy
C) overall size
D) abundance of hair
E) It has evolved in all these respects.
34. Which of the following structures is NOT homologous to the others?
A) alligator forelimb
B) bird wing
C) human arm
D) insect wing
E) bat wing
35. Boa constrictors have tiny pelvic girdles and leg bones within their bodies. Since
these structures are nonfunctional, they are called
A) extra.
B) analogous.
C) maladaptive.
D) homologous.
E) vestigial.
36. The many different breeds of domestic dog were produced by
A) natural selection.
B) artificial selection.
C) kin selection
D) mutation.
E) divergent evolution
37. Most commercial pesticides are effective for only 2-3 years. This is because
A) new pests invade the area.
B) the chemicals induce mutations that convey immunity.
C) the chemicals mutate.
D) the pests learn to ignore the chemicals.
E) those pests with advantageous mutations will survive and reproduce.
38. Evolution can be defined as
A) a change in the genetic makeup of a population over time.
B) a change in form of an organism.
C) a change in the genetic makeup of an organism.
D) an organism growing into another type of organism.
E) none of the above
39. If within a large population no mutations occur, no migration occurs, all matings
are random, and each individual has an equal chance of reproducing, which of
the following will probably happen?
A) Extinction will occur.
B) A bottleneck will occur.
C) Natural selection will occur at the normal rate for that species.
D) A change in allele frequency will lead to rapid evolution.
E) No evolution will occur
40. Which of the following can cause evolutionary change?
A) genetic drift in a small population
B) mutation
C) natural selection
D) Two of these are correct.
E) A, B, and C are all correct
41. Founder populations may quickly become very different from the parent
population in a similar habitat due to
A) natural selection.
B) artificial selection.
C) bottleneck.
D) genetic drift.
E) mutation.
42. A small population is likely to evolve because of ________, but this is not likely to
be true for large populations.
A) sexual selection
B) genetic drift
C) mutations
D) nonrandom mating
E) natural selection
43. A population with ________ is at risk for extinction.
A) large size
B) low genetic variation
C) too little gene flow
D) low levels of genetic drift
E) random mating
44. Mutations
A) are random.
B) occur to solve problems for species (are goal oriented).
C) can alone cause drastic changes in the gene frequencies of a population.
D) Only choices A and B are correct.
E) are always detrimental.
45. Imagine a population of monkeys in South America whose habitat has been
reduced to the point where only 25 monkeys survive. This is an example of
A) genetic drift.
B) founder effect.
C) natural selection.
D) population bottleneck.
E) all of these
46. Having greater evolutionary fitness means
A) having more offspring.
B) having greater strength.
C) being able to produce more sperm or eggs.
D) being able to survive better.
E) being larger
47. The sexual displays and contests common in the Animal Kingdom (such as male
Bighorn Sheep bashing their heads together) result in
A) random mating.
B) sexual selection.
C) mutations.
D) stabilizing selection.
E) disruptive selection
48. Natural selection acts on ________ to affect the evolution of ________.
A) genotypes; mutations
B) genotypes; populations
C) genotypes; individuals
D) phenotypes; populations
E) phenotypes; individuals
49. Giraffe leg and neck length increased under ________ selection, but currently is
probably maintained by ________ selection.
A) directional; disruptive
B) directional; stabilizing
C) disruptive; stabilizing
D) stabilizing; disruptive
E) disruptive; directional
50. Multidrug-resistant bacteria worldwide
A) have been eradicated.
B) are becoming less widespread.
C) have always been common in the natural environment.
D) are not serious threats to human health.
E) are becoming more widespread.
LABEL
I.. Selection can be of 3 different kinds, according to this diagram. Label each of these types of selection as
they appear.
II. This diagram indicates the heredity pattern for sickle cell anemia. The H indicates normal hemoglobin; the
h indicates sickling hemoglobin. Analyze the image and label the circles appropriately. Indicate which
individual will survive, which will die of malaria, and which will die of sickle cell anemia.
B ____________________
A ____________________
C _________________