III Unit PRACTICE Exam #2
BSC 2011
Fall 2007
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) The ostrich and the emu look very similar and live in similar habitats, however they are not very closely related.
This is an example of _______.
A) sympatric speciation. B) divergent evolution. C) convergent evolution. D) exaptation. E) adaptive radiation.
2) The correct sequence from the most to the least comprehensive of the taxonomic levels listed here is
A) kingdom, phylum, order, class, family, genus, and species.
B) phylum, family, class, order, kingdom, genus, and species.
C) phylum, kingdom, order, class, species, family, and genus.
D) kingdom, phylum, class, order, family, genus, and species.
E) family, phylum, class, kingdom, order, species, and genus.
_______.
5) Which statement represents the best explanation for the observation that the nuclear DNA of wolves and
domestic dogs has a very high degree of homology?
A) Dogs and wolves shared a common ancestor very recently.
B) Dogs and wolves have very similar morphologies.
C) Dogs and wolves are both members of the family Canidae.
D) Convergent evolution has occurred.
E) Dogs and wolves belong to the same order.
17) Which of the following would be an example of macroevolution?
A) evolution of polymorphism in Papilio dardanus, with each morph mimicking a different protected butterfly
B) evolution of antibiotic resistance in a strain of E. coli
C) evolution of modern humans, Homo sapiens, from australopithecine ancestors
D) replacement of a melanin-poor morph by a melanin-rich morph over many generations under conditions of
increased UV exposure
E) evolution of insecticide resistance in populations of insect pests treated through the years with DDT
Use the following information to answer the following THREE questions below.
A large population of laboratory animals has been allowed to breed randomly for a number of generations. After
several generations, 36% of the animals display a recessive trait (aa), the same percentage as at the beginning of the
breeding program. The rest of the animals show the dominant phenotype, with heterozygotes indistinguishable from
the homozygous dominants.
18) What is the most reasonable conclusion that can be drawn from the fact that the frequency of the recessive trait
(aa) has not changed over time?
A) The two phenotypes are about equally adaptive under laboratory conditions.
B) The genotype AA is lethal.
C) There has been sexual selection favoring allele a.
D) The population is undergoing genetic drift.
E) There has been a high rate of mutation of allele A to allele a.
19) What is the estimated frequency of allele a in the gene pool?
A) 0.40
B) 0.60
C) 0.70
D) 0.18
E) 0.80
20) What proportion of the population is probably heterozygous (Aa) for this trait?
A) 0.48
B) 0.72
C) 0.60
D) 0.36
E) 0.18
21) All of the following are criteria for maintaining Hardy-Weinberg equilibrium involving two alleles except ____.
A) there should be no natural selection.
B) matings must be random.
C) gene flow from other populations must be zero.
D) populations must be large.
E) the frequency of all genotypes must be equal.
Use the following information to answer the FOUR questions below.
In a hypothetical population of 1,000 people at Hardy-Weinberg equilibrium and one in which all possible blood
types are represented, tests of blood-type genes show, in part, that 250 have the genotype AA and 40 have the
genotype BB.
22) What is the frequency of the A allele?
A) 0.632
B) 0.200
C) 0.500
D) 0.250
E) 0.400
23) What percentage of the population has type AB blood?
A) 0
B) 40
C) 70
D) 10
E) 20
24) What percentage of the population has type O blood?
A) 0
B) 9
C) 10
D) 24
E) 48
25) If there are 6,000 children born to this generation, how many would be expected to have type BB blood under
the conditions of Hardy-Weinberg equilibrium?
A) 40
B) 2,400
C) 960
D) 240
E) 100
26) In peas, a gene shows incomplete dominance for flower color such that RR = purple, Rr = pink, and r = white.
In an isolated pea patch, a killing frost takes the population out of H/W equilibrium and leaves only 36 plants with
white flowers, 7 with pink flowers, and 14 with purple flowers. What is the frequency of the recessive allele in the
surviving population population?
A) 0.31
B) 0.69
C) 0.63
D) 0.60
E) 0.37
28) Through time, the movement of people on Earth has steadily increased. This has altered the course of human
evolution by increasing _______.
A) nonrandom reproduction
B) genetic drift C) geographic isolation
D) gene flow
E) mutations.
29) When we say that an individual organism has a greater fitness than another individual, we specifically mean
that the organism _______.
A) lives longer than others of its species.
B) competes for resources more successfully than others of its species.
C) mates more frequently than others of its species.
D) leaves more viable offspring others than of its species.
E) utilizes resources more efficiently than other species occupying similar niches.
30) Which of the following statements best summarizes evolution as it is viewed today?
A) It represents the result of selection for acquired characteristics.
B) It is synonymous with the process of gene flow.
C) It is the descent of humans from the present-day great apes.
D) It is the differential survival and reproduction of the most fit phenotypes.
E) It is goal-directed.
31) Cattle breeders have improved the quality of meat over the years by which process?
A) directional selection
B) artificial selection
C) stabilizing selection
D) A and B
E) A and C
32) Which of the following is most likely to have been produced by sexual selection?
A) bright colors of female flowers
B) camouflage coloration in animals
C) a male lion's mane
D) different sizes of male and female pinecones
E) the ability of desert animals to concentrate their urine
33) When imbalances occur in the sex ratio of sexual species that have two sexes (i.e., other than a 50:50 ratio), the
members of the minority sex often receive a greater proportion of care and resources from parents than do the
offspring of the majority sex. This is most clearly an example of _______.
A) frequency-dependent selection.
B) sexual selection.
C) disruptive selection.
D) balancing selection.
E) stabilizing selection.
34) In the mid-1900s, the Soviet geneticist Lysenko exposed winter wheat plants to ever-colder temperatures,
collected their seeds, and then exposed the seedlings to ever-colder temperatures. He repeated his attempts over the
course of decades in an attempt to evolve cold-tolerant winter wheat. Lysenko's attempts in this regard were most in
agreement with the ideas of _______.
A) Hutton
B) Lamarck
C) Cuvier
D) Plato
E) Darwin
35) Who was the naturalist who developed a concept of natural selection independently of Darwin?
A) John Henslow
B) Charles Lyell
C) Thomas Malthus
D) Gregor Mendel
E) Alfred Wallace
36) If the HMS Beagle had completely bypassed the Galapagos Islands, Darwin would have had a much poorer
understanding of _______.
A) the ability of populations to undergo modification as they adapt to a particular environment.
B) the tendency of organisms to produce a larger number of offspring than the environment can support.
C) the age of Earth.
D) the limited resources available to support population growth in most natural environments.
E) how fossils of marine organisms could be found high in the Andes.
37) DDT was once considered a "silver bullet" that would permanently eradicate insect pests. Today, instead, DDT
is largely useless against many insects. What would need to be true for pest eradication efforts to have been
successful in the long run?
A) DDT application should have been continual.
B) All habitats should have received applications of DDT at about the same time.
C) Larger doses of DDT should have been applied.
D) All individual insects should have possessed genomes that made them susceptible to DDT.
E) The frequency of DDT application should have been higher.
38) Structures as different as human arms, bat wings, and dolphin flippers contain many of the same bones, these
bones having developed from the same embryonic tissues. How do biologists interpret these similarities?
A) by proposing that humans, bats, and dolphins share a common ancestor
B) by the principle of convergent evolution
C) by identifying the bones as being homologous
D) A and C only
E) A, B, and C
39) Members of two different species possess a similar-looking structure that they use in a similar fashion to
perform the same function. Which information would shed the most light on whether these structures are
homologous or whether they are, instead, the result of convergent evolution?
A) The two species share many proteins in common, and the nucleotide sequences that code for these proteins are
almost identical.
B) Both species are well adapted to their particular environments.
C) The sizes of the structures in adult members of both species are similar in size.
D) Both species reproduce sexually.
E) The two species live at great distance from each other.
40) The theory of evolution is most accurately described as _______.
A) a broad explanation, supported by much evidence, for how populations change over time.
B) an educated guess about how species originate.
C) an opinion that some scientists hold about how living things change over time.
D) an idea about how acquired characteristics are passed on to subsequent generations.
E) one possible explanation, among several scientific alternatives, about how species have come into existence.
ANSWERS:
1. c
21. e
2. d
22. c
23. e
24. b
5. a
25. d
26. b
17. c
18. a
19. b
20. a
28. d
29. d
30. d
31. d
32. d NO! Correct answer is of course C
33. c NO! correct answer is of course A
34. a or b or e NO! correct answer is of course B
35. e
36. a
37. d
38. d
39. a
40. a