AP Biology Practice Exam #6
                                               Subunit #6: Evolutionary Biology

_____1. Which of the following pairs of structures are analogous?
a) horse's leg and human forearm                    c) insect's wing and bird's wing
b) bat's wing and dolphin's flipper               d) hummingbird's wing and seal's flipper

_____2. In order to be considered an evolutionarily favorable trait for an organism, a trait must increase the individuals
a) fitness   b) health       c) lifespan      d) range

_____3. If Lamarck's hypothesis of species modification were true, the children of a person who developed
large muscles by lifting weights would be born with
a) smaller than average muscles
b) normal sized muscles
c) normal sized muscles that would become larger only if the children also lifted weights
d) larger than average muscles

_____4. Darwin's theory of descent with modifications states that
a) newer forms appearing in the fossil record are the modified descendents of older species.
b) organisms that descended from high elevations are modified as they acquire new traits.
c) all living things descended from a recent common ancestor on the Galapagos Islands.
d) individuals modify their behavior to survive and then pass those modifications on to their descendents.

_____5. In an evolutionary sense, an individual organism has high fitness if it
a) has a large number of acquired traits.
b) can run long distances without becoming exhausted.
c) reproduces more successfully than other individuals.
d) evolves into another organism rather than becoming extinct.

_____6. Toads in a particular population vary in size. A scientist observes that in this population, large males mate with females significantly
more often than small males do. All the following are plausible hypotheses to explain this observation EXCEPT:
a) Females select large males more often than they select small males as mates.
b) Small females are more likely to mate with small males and large females are more likely to mate with large males.
c) Large males occupy more breeding territory than small males do.
d) The calls produced by large males are more attractive to females than the calls made by small males.
e) Large males are successful in competing for mates more often than small males are.

_____7. According to the law of superposition, the lowest layer in a cross section of rock
a) is the most recent                           c) is the oldest
b) has fewest fossils                           d) contains only fossils of burrowing animals

_____8. Which of the following principles is NOT part of Darwin’s theory of evolution by natural selection?
a) Individuals that possess the most favorable variations have the best chance of reproducing.
b) Evolution is a gradual process that occurs over long periods of time.
c) Variation occurs among individuals in a population.
d) Mutations are the ultimate source of genetic variation.
e) More individuals are born than will survive.

_____9. Cuvier addressed the comparative anatomy of fossils in a theory of life changes called
a) paleontology
b) the inheritance of acquired characteristics
c) the evolution of species
d) catastrophism
e) uniformitarianism

_____10. The wing of a bat, the flipper of a whale, and the forelimb of a horse appear very different, yet detailed studies reveal the presence
of the same basic bone pattern. These structures are examples of
a) balanced polymorphism
b) convergent evolution
c) analogous structures
d) homologous structures
e) vestigial structures
_____11. Hutton's theory of geological change included all Except
a) catastrophic extinction of species.
b) slow cycles of erosion and uplift.
c) production of layers of sediment through slow deposition.
d) extreme geological change occurring over a long period of time.

_____12. Natural selection was independently purposed as a means of evolution by Darwin and
e) Lyell   b) Wallace     c) LeClerc    d) Lamarck

_____13. Which is Not one of the preconditions in a population where natural selection is at work?
a) There is variation that can be inherited in a population.
b) The population becomes adapted to its environment.
c) Many more individuals are produced by a population than can survive and reproduce.
d) Adapted characteristics in some individuals make them more likely to survive and reproduce.

_____14. Which of the following is/are true about natural selection?
a) It acts on genotypes rather than phenotypes.
b) It assures the survival of each fit individual.
c) On average, it favors the survival of more young with adaptive characteristics.
d) It always selects for more complex forms.
e) All of the above are correct.

_____15. Although the seal and the penguin both have streamlined, fishlike bodies with a layer of insulating fat, they are not closely related.
This similarity results from
a) homologous evolution
b) coevolution
c) parallel evolution
d) convergent evolution
e) adaptive radiation

_____16. Birds and insects both have wings, but we do not consider this similarity as evidence of relatedness because
a) bird wings function on different physics principles of lift.
b) insect wings are vestigial.
c) the wings are not homologous structures with a common ancestral origin.
d) they did not evolve in the same region or live at the same time period.
e) there is no fossil link between these groups.

_____17. Which of the following appendages is analogous to a bat wing?
a) Forelimb of a frog b) Eagle wing c) Housefly wing d) Whale flipper         e) Human arm

_____18. Natural selection could Not occur without
a) genetic variation in species                 c) environmental changes
b) competition for resources                   d) gradual warming of he Earth

_____19. Directional selection occurs when
a) the extremes of a population have a better chance to survive
b) the organisms on one extreme of the population have a better chance to survive than those on the other extreme
c) the environment controls which organisms will survive
d) humans determine which organisms will survive
e) the extremes of a population have a lesser chance to survive

_____20. An isolating mechanism in which gamete exchange between two groups is prevented because each group
possesses its own characteristic courtship behavior, is called
a) gametic isolation
b) reproductive isolation
c) sympatric speciation
d) behavioral isolation
e) mechanism isolation

_____21. A prezygotic isolating mechanism in which sexual reproduction between two individuals cannot occur because
of chemical differences between the gametes of the two species, is called
a) behavioral isolation b) gametic isolation c) mechanism isolation d) reproductive isolation

_____22. The evolution of several to many species from an unspecialized ancestor, is called
a) allopatric speciation b) speciation c) adaptive radiation d) mechanism isolation e) sympatric speciation
_____23. The evolution of a new species within the same geographical region as the parent species, is called
a) speciation b) adaptive radiation c) mechanism isolation d) sympatric speciation e) allopatric speciation

_____24. Natural selection that acts against extreme phenotypes and favors intermediate variants, is called
a) directional selection
b) heterozygote advantage
c) disruptive selection
d) stabilizing selection
e) balanced polymorphism

_____25. Stabilizing selection occurs when
a) humans determine which organisms will survive
b) the extremes of a population have a lesser chance to survive
c) the extremes of a population have a better chance to survive
d) the organisms on one extreme of the population have a better chance to survive than those on the other extreme
e) the environment controls which organisms will survive

_____26. A phenomenon in which the heterozygous condition confers some special advantage on an individual
that either homozygous does not, is called
a) disruptive selection
b) balanced polymorphism
c) founder effect
d) gene pool
e) heterozygote advantage

_____27. The presence in a population of two or more genetic variants that are maintained in a stable frequency over several generation, is
a) balanced polymorphism
b) directional selection
c) disruptive selection
d) natural selection
e) stabilizing selection

_____28. Which statement is Not true about natural selection?
a) Directional selection occurs when one extreme phenotype is favored over another different extreme phenotype.
b) Stabilizing selection favors an intermediate phenotype over either of the extreme phenotypes.
c) Disruptive selection favors both of the extreme phenotypes over the intermediate phenotype.
d) Directional selection leads to improved selection when the environment remains the same.
e) Disruptive selection leads to polymorphism, favoring different forms of the same species.

_____29. Which of the following is true about genetic drift?
a) It is more likely to occur in a large population than in a small population.
b) It may lead to an allele's becoming fixed in a population when alternative allele is lost from the population.
c) It increases the number of heterozygotes in a population.
d) It increases the level of rare alleles in a population.

_____30. The most common source of genetic variations in sexually reproducing organisms is
a) mutations b) recombination of alleles c) duplication of chromosomes d) duplication of genes

_____31. The evolutionary force that operates primarily through chance is
a) none of the above
b) natural selection
c) genetic drift
d) isolation
e) mating preference

_____32. A change in a regulatory gene
a) must be dominant to be effective.
b) is what happens in the production of sickle cell hemoglobin.
c) is always beneficial to the organism in which it occurs.
d) can increase or decrease the expression of a structural gene.

_____33. Which of the following is a correct statement about mutations?
(A) They are a source of variation for evolution.
(B) They drive evolution by creating mutation pressures.
(C) They are irreversible.
(D) They occur in germ cells but not in somatic cells.
(E) They are most often beneficial to the organisms in which they occur.
_____34. Drug resistance mutations occurs in bacteria
a) only when they are exposed to the drug to which they become resistant.
b) more often when they are exposed to the drug.
c) at any time, even when they are not exposed to the drug.
d) only when they are exposed to radiation or other mutagens.

_____35. All the members of a single species that occupy a particular area at the same time are known as a
a) subspecies b) gene pool c) population d) group e) sub-population

_____36. In a certain population of squirrels that is in Hardy-Weinberg equilibrium, black color is a recessive phenotype
present in 9 percent of the squirrels, and 91 percent are gray. What percentage of the population is homozygous dominant for this trait?
a) 21%     b) 30%      c) 49%      d) 70%       e) 91%

Questions 37-41 refer to the following:
A moth’s color is controlled by two alleles, G and g, at a single locus. G (gray) is dominant to g (white). A large population of moths was
studied, and the frequency of the G allele in the population over time was documented, as shown in the figure below. In 1980 a random
sample of 2,000 pupae was collected and moths were allowed to emerge.

_____37. During which of the following time periods could the population have been in Hardy-Weinberg equilibrium for the G locus?
I. 1960-1964
II. 1965-1972
III. 1973-1980
a) I only
b) II only
c) III only
d) I, II, and III
e) I and III only

_____38. Assuming that the population was in Hardy-Weinberg equilibrium for the G locus, what percentage of moths in the natural
population was white in 1962?
a) 64%
b) 20%
c) 8%
d) 4%
e) 2%

_____39. Assuming that the population was in Hardy-Weinberg equilibrium for the G locus, what percentage of the gray moths that
emerged in 1980 was heterozygous?
a) 100%
b) 67%
c) 33%
d) 25%
e) 0%

_____40. Assuming that the population was in Hardy-Weinberg equilibrium for the G locus, what was the frequency of allele G in the gray
moths that emerged in 1980?
a) 0.33
b) 0.50
c) 0.67
d) 0.75
e) 1.00

_____41. Which of the following is the most likely reason for the observed differences in the frequency of the G allele between 1965 and
a) Selection against gray phenotypes
b) Speciation
c) Mutation
d) Emigration of white moths from the population
e) Chance

_____42. The relatives of a group of pelicans from the same species that separated from each other because of an
unsuccessful migration are reunited 150 years later and find that they are unable to produce offspring. This is an example of
a) sympatric speciation b) genetic drift c) gene flow d) allopatric speciation e) natural selection

_____43. A large population that is reduced to a few surviving individuals is said to have gone through a(n)
a) founder effect b) bottleneck c) inbreeding depression d) extinction event e) equilibrium effect

_____44. Unlike the situation today, the early atmosphere of the Earth probably contained very little
a) oxygen b) nitrogen c) ammonia d) methane e) hydrogen

_____45. Which of the following is probably the best explanation for the fact that Antarctic penguins cannot fly, although there is evidence
that millions of years ago their ancestors could do so?
a) Penguins live on land and feed in the water; therefore they have no need to fly.
b) The Antarctic home of the penguins is flat and barren; therefore there is no place to fly.
c) Ancestral penguins without large wings were better able to swim and feed in the water; therefore they passed their genes for shorter wing
structure on to their offspring.
d) Ancestral penguins did not use their wings for long periods of time; therefore today’s penguins have only tiny, nonfunctional wings.
e) The cold and wind of Antarctica make flight impossible; therefore penguins that live there have lost the ability to fly.

_____46. All of the following were likely present on the primitive Earth during the evolution of self-replicating molecules EXCEPT
a) amino acids and nucleotides
b) nitrogen
c) simple carbohydrates
d) freestanding liquid water
e) an O2 rich atmosphere

_____47. Because of its widespread use in all living organisms, ______ is thought to have been one
of the earliest metabolic pathways developed by life.
a) glycolysis b) fermentation c) the Krebs cycle d) photosynthesis

_____48. Lynn Margulis hypothesized that today's eukaryotic cells are the descendents of an early
symbiotic relationship established when an ancestral cell was inhabited by some of the ancestors of
today’s organelles. Which organelles did she use in her theory?
a) nuclei, mitochondria
b) nuclei, chloroplasts
c) mitochondria, chloroplasts
d) mitochondria, vacuoles
e) nuclei, Golgi apparatus

_____49. Experiments like those performed by Stanley Miller in 1953 demonstrated that
a) A lipid-protein film will eventually be formed by thermal convection
b) Complete, functioning prokaryotic cells are formed after approximately three months
c) DNA forms readily and reproduces itself
d) Many of the lipids, carbohydrates, proteins, and nucleotides required for life can form under abiotic conditions
e) All of the above

_____50. Which of the following is the strongest evidence for the hypothesis that present-day eukaryotic anaerobes are the descendants of
the successful symbiotic association of anaerobes and mitochondria?
a) a mitochondrion can survive indefinitely when removed from a eukaryotic cell
b) mitochondria can produce ATP
c) fossilized mitochondria are older than the oldest fossilized eukaryotes
d) a mitochondrion has its own set of DNA molecules
Questions 51-54 refer to the following directions.
    The group of questions below consists of five lettered headings followed by a list of numbered phrases or sentences. For each
numbered phrase or sentence select the one heading that is most closely related to it and fill in the corresponding bubble on your scantron
sheet. Each heading may be used once, more than once, or not at all.
     From the fields of study listed below, choose the field that has provided each of the following pieces of evidence that biological
evolution has occurred.

a)   comparative anatomy
b)   comparative biochemistry
c)   comparative embryology
d)   geographical distribution
e)   paleontology

_____51. Archeopteryx is an extinct feathered reptile.

_____52. Peripatus has claws like an insect and paired nephridia like a segmented worm.

_____53. Most human diabetics can use insulin derived either from pigs or from humans.

_____54. During early development, a human fetus has a tail and gill arches.

_____55. The branch of biology concerned with identifying, naming, and classifying organisms
according to their characteristics and evolutionary history is
a) nomenclature b) classification c) hierarchy d) taxonomy e) cladistics

_____56. The scientific name of the giant swallowtail is "Heraclides cresphontes". Therefore,
a) it belongs to the genus "Heraclides".    c) it belongs to the species "cresphontes".
b) the specific epithet is "cresphontes".   d) All of the above are correct.

_____57. The distinction between cytochrome "c" of chickens and humans versus chickens and ducks was a difference determined by
a) sequencing of mtDNA
b) sequencing of rDNA
c) DNA - DNA hybridization
d) sequencing of amino acids
e) immuno-rejection of antibodies

______58. The fact that humans and cats are classified as mammals provides us with which minimum of information?
a)cats evolved from other cats
b)humans evolved from cats
c)cats and humans are unrelated organisms
d)cats and humans have a common ancestor
e)none of the above

______59. In a certain flock of sheep, 4 percent of the population has black wool and 96 percent has white wool. Assume that the population
is in Hardy-Weinberg equilibrium. If black wool is a recessive trait, what percentage of the population is heterozygous for this trait?
a) 80%
b) 64%
c) 32%
d) 20%
e) 4%

______60. In a certain flock of sheep, 4 percent of the population has black wool and 96 percent has white wool. Assume that the population
is in Hardy-Weinberg equilibrium. What percentage of the population is homozygous for white wool?
a) 96%
b) 80%
c) 64%
d) 40%
e) 20%

______61. The persistence of the sickle-cell anemia allele in the African population is the result of
a) the advantage of the heterozygous form over the homozygous forms
b) nonrandom mating
c) a decline in the occurrence of malaria in Africa
d) a high rate of mutation of the normal allele to the sickle-cell anemia allele
e) none of the above

______62. Four of the five answers listed below are types of selection exhibited by nature. Select the exception.
a) sexual
b) artificial
c) disruptive
d) stabilizing
e) directional

______63. Genetic variation is the result of all but which of the following?
a) the role of the environment in controlling genetic expression
b) crossing over and genetic recombination
c) alteration of chromosome structure or number
d) gene mutation
e) independent assortment

______64. Microevolution is the result of
a) natural selection
b) chance variation
c) change in gene frequency
d) mutation
e) all of the above

Questions 65-66 refer to the following chart.
The following chart is a comparison of the amino acid differences in cytochrome C between Organism X and five other organisms.

                                 Organism                                                                # Amino Acid Differences
                                    A                                                                               1
                                    B                                                                              12
                                    C                                                                               4
                                    D                                                                              43
                                    E                                                                              46

______65. Based on the chart for cytochrome C amino acids, which organism is the most closely related to organism X?
a) A
b) B
c) C
d) D
e) E

______66. Is it correct to infer that organisms D and E are closely related to each other?
a) yes, but other evidence must also be considered before a comparison is made
b) yes, because almost all their amino acids must be similar to each other
c) yes, because they both have a similar number of amino acids different from organism X
d) no, because if their sequences are not similar to organism X, then their sequences are not likely to be similar to each other
e) no, because their amino acid sequences must be compared with each other in order to determine if they are similar

_____67. In a population of giraffes, an environmental change occurs that favors individuals that are tallest. As a result,
more taller individuals are able to obtain nutrients and survive to pass along their genetic information. This is
a) artificial selection b) stabilizing selection c) natural selection d) sexual selection e) directional selection

_____68. An organism that lives within another organism for the benefit of both is an association called
a) parasitism b) endosymbiosis c) heterotrophism d) glycolysis e) existentialism

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