Download Numbers of reported cases of bedbug infestations have been

PROCTOR VERSION
1.5 C: Role of the Environment in Evolution Quiz
1.
Numbers of reported cases of bedbug infestations have been increasing over the past ten years
in the United States. In an attempt to combat the infestations, people began using pesticides to
kill the bedbugs, but now many bedbugs are resistant to the two most common pesticides.
The map below shows the percentages of bedbugs that are resistant to treatment in locations
across the United States. The different shades in the pie chart for a certain location show the
proportions of the population in that location that have mutations for resistance to one, both, or
neither of the pesticides.
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PROCTOR VERSION
1.5 C: Role of the Environment in Evolution Quiz
Which statements best explain how the two strains of resistance may have occurred and
recommend the best course for future eradication of bedbugs?
(A) The continued use of pesticides by humans has allowed bedbugs to adapt to the pesticides
so that, if a bedbug survives an exposure, the bedbug will develop a resistance to the
pesticide. To combat this resistance, stronger pesticides must be used.
Distractor Rationale:
This answer suggests the student may understand that populations adapt to changes in their
environment, but does not understand that individuals do not adapt but either survive or do
not survive, and does not understand that increasing the concentration will probably select
for those individuals resistant to higher concentrations of pesticide. The student may not
recognize the role human actions play in the epidemic and how the overuse of pesticides
has contributed to the increased resistance in the bedbug population.
(B) When a bedbug population is almost eliminated by exposure to a pesticide, the bedbug
population experiences a genetic bottleneck (genetic drift) that results in the expression of
new genes. The new genes protect the survivors, so new bedbugs without the resistance
genes should be introduced into the bedbug population to weaken the population’s
resistance to the pesticides.
Distractor Rationale:
This answer suggests the student may understand that a genetic bottleneck (an event that
decreases the genetic diversity in a population due to a decrease in population size) often
results in changes in gene frequencies, but does not understand that a bottleneck only
removes genes from the gene pool, and does not understand that introducing non-resistant
bedbugs would not be effective since these bedbugs would be selected against during every
pesticide application. The student may not recognize the role human actions play in the
epidemic and how the overuse of pesticides has contributed to the increased resistance in
the bedbug population.
(C) The continued use of pesticides has selected for bedbugs that have some resistance to the
pesticide, and over time the resistance has been passed on to offspring and increased
within the population. To effectively deal with this resistance, different and new types of
pesticides must be used.
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PROCTOR VERSION
1.5 C: Role of the Environment in Evolution Quiz
Rationale:
This answer suggests the student understands that repeated pesticide use is selecting for
pesticide resistance in the bedbug population, and that over time more bedbugs have
become resistant because survivors have passed on this resistance. The student also
understands that since all of the existing pesticides are similar in how they function,
development of different and new pesticides is required.
(D) The bedbug population can more effectively deal with low doses of various pesticides in the
environment and is becoming immune to the pesticides. In order to effectively kill all
bedbugs, one pesticide should be used at a time, and it should be used at a high
concentration.
Distractor Rationale:
This answer suggests the student may understand that low levels of pesticide use may allow
for survival of individuals with lower resistance, but does not understand that increasing
the concentration will probably select for those individuals resistant to higher concentrations
of pesticide. The student may not recognize the role human actions play in the epidemic
and how the overuse of pesticides has contributed to the increased resistance in the bedbug
population.
Aligned to: LO 1.5 CA 1.5: Impact of Environment on Evolution
Page 3 of 9
PROCTOR VERSION
1.5 C: Role of the Environment in Evolution Quiz
2.
The Central European blackcap is a bird that spends its summers in Germany and historically
spent its winters in Spain. About 50 years ago, however, backyard bird feeding became popular
in Britain. With a ready supply of food in Britain, some blackcaps began to migrate northwest,
instead of southwest to Spain, and were able to survive and return to their summer breeding
grounds in Germany. (The birds begin their mating season soon after they arrive back in
Germany from their wintering grounds. Migration is an innate, genetically controlled behavior.)
Over time, the percentage of the population that migrates to Britain has increased. Today, about
10% of the population winters in Britain instead of Spain. The blackcap migratory routes are
shown in the map below.
The two populations of blackcaps have been studied, and the observations shown in the chart
below have been made. These differences have taken only 30 generations to appear.
Page 4 of 9
PROCTOR VERSION
1.5 C: Role of the Environment in Evolution Quiz
Which statements best explain the differences in phenotypes observed in the two blackcap
populations?
(A) The differences are due to the Britain-wintering blackcaps migrating to a new area and
interbreeding with other populations of blackcaps. This interbreeding introduces new alleles
into the population and changes the frequency of specific phenotypes in the area.
Distractor Rationale:
This answer suggests the student may understand that when new populations are
introduced, changes in allele frequency can lead to phenotypic changes, but does not
understand that interbreeding would probably not occur because the birds return to
Germany to breed.
(B) The differences are due to the Britain-wintering blackcaps migrating shorter distances and
having different food sources in their winter habitats. These changes are selecting for
different variations within the population and producing the changes observed.
Rationale:
This answer suggests the student understands that when birds take different migratory
routes, they encounter different selective forces that act unequally on different phenotypes in
the population and produce evolutionary change. Britain-wintering blackcaps show the
phenotypic traits of narrow, long beak and short, wide wing phenotypes because they
experience environmental factors, such as the different types of food in the wintering ground
and the short length of the migration route, that select for these specific phenotypes. Britainwintering blackcaps also arrive back in Germany and begin breeding before Spain-wintering
blackcaps, further isolating the two groups. The student is able to make the correlation
between specific environmental factors and the patterns in the Britain-wintering blackcap
phenotypes.
(C) The differences are due to the Spain-wintering blackcaps developing long wings and wide
beaks over their lifetimes, whereas the Britain-wintering blackcaps do not develop these
characteristics. The Spain-wintering blackcaps’ developed characteristics are passed
directly to the next generation and add up over many generations.
Distractor Rationale:
This answer suggests the student may understand that different selective pressures may
produce changes in populations, but does not understand that instead of individuals
passing characteristics developed during their lifetimes to the next generation, selective
pressures act on populations, because some individuals with advantageous traits have a
better chance of surviving and passing on those traits.
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PROCTOR VERSION
1.5 C: Role of the Environment in Evolution Quiz
(D) The differences are due to the small population size of the Britain-wintering blackcaps. This
small population has lost genetic diversity due to a genetic bottleneck, and as a result,
random changes have occurred in gene frequencies and population phenotypes.
Distractor Rationale:
This answer suggests the student may understand that small populations are subject to
random changes due to genetic drift, but does not understand that different migration
patterns and diets play significant roles in changes within populations, because these
selective pressures will act on the populations regardless of size.
Aligned to: LO 1.5 CA 1.5: Impact of Environment on Evolution
3.
The graph below shows variation in the pigmentation of a frog population living in a Central
American rain forest.
This frog species is one of many green frog species that live in the rain forest, but this species
displays a wider range of pigmentation phenotypes than most of the other green frog species. All
of the green frog species are preyed upon by snakes, birds, and small mammals. A mutation
occurs in this frog species that produces a toxic secretion from the skin, which does not hurt the
frog but makes the frog taste unpleasant to predators.
Which statement best predicts the likely change in pigmentation phenotype in the frog population
as this mutation becomes more prevalent?
(A) Because green pigmentation provides the best camouflage, there will be an increase in
green pigmentation and a decrease in yellow-green and blue-green pigmentation, since
these colors are easier to see in a rain forest environment.
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PROCTOR VERSION
1.5 C: Role of the Environment in Evolution Quiz
Distractor Rationale:
This answer suggests the student may understand that some phenotypes increase fitness
because they make individuals harder to see, but does not understand that an individual
that is toxic would have greater fitness if it also had warning coloration, since this would
allow predators to avoid it. The student may not recognize that predation and the presence
of other, non-toxic green frogs are the environmental factors in this scenario.
(B) Because female frogs find bright colors more attractive and the toxic secretions make
camouflage less important, there will be an increase in yellow-green and blue-green
pigmentation in the frog population.
Distractor Rationale:
This answer suggests the student may understand that some phenotypes increase fitness
because they increase reproductive success, but does not understand that, in this
environment, a phenotype that differs from that of other, non-toxic frog species will increase
fitness because increased survival will lead to increased reproductive success.
(C) Because toxic frogs with green pigmentation resemble other non-toxic green frogs, there will
be an increase in yellow-green and blue-green pigmentation, since these colors are easier
for predators to recognize and avoid.
Rationale:
This answer suggests the student understands that a toxic prey species has a greater
selective advantage if it has coloration that allows predators to recognize and avoid it.
Predators will begin to avoid the yellow-green and blue-green phenotypes of the toxic frog,
leading to an increase in the frequency of these two colors. Because the toxic green frogs
will not be readily distinguishable from the non-toxic green frogs, they will not be avoided by
predators and therefore will not increase in frequency.
(D) Because blue pigmentation is more commonly associated with toxic organisms than yellow
or green pigmentations are, there will be an increase in blue-green pigmentation and a
decrease in yellow-green and green pigmentation, as species with these phenotypes will be
mistaken for non-toxic species and will suffer higher rates of predation.
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PROCTOR VERSION
1.5 C: Role of the Environment in Evolution Quiz
Distractor Rationale:
This answer suggests the student may understand that blue pigmentation is commonly
associated with toxic or unpalatable species, but does not understand that any form of
recognizable warning coloration could provide for greater fitness for individuals with a
chemical defense, because the student may not recognize that predation and the presence
of other, non-toxic green frogs are the environmental factors in this scenario.
Aligned to: LO 1.5 CA 1.5: Impact of Environment on Evolution
4.
Biologists are studying how the unique environmental conditions found in Africa’s Lake Victoria
may affect the cichlid fish living in the lake. The cichlid fish are present in a wide diversity of
colors. Due to the presence of yellow-green phytoplankton and dissolved organic matter in Lake
Victoria, blue light dominates the visual environment at the surface, but in deep water, red light
dominates. Female cichlids prefer to mate with brightly colored males, and blue males will reflect
more blue light while red males reflect more red light, so there is a population of blue cichlids in
shallow water and a population of red cichlids in deep water.
Recent logging around the lake has caused the water to become cloudy with silt (pieces of fine
sand and clay), and now neither blue nor red light travels to significant depths in the lake.
Which statement predicts what is most likely to occur in the cichlid populations in Lake Victoria if
the cloudy water conditions persist for a long time?
(A) Because there is no longer a selective advantage to having red or blue coloration for males
at either depth, neither color will be favored at either depth, and the two populations will
begin to interbreed and lose their unique colorations.
Rationale:
This answer suggests the student understands that if the environment changes and no
longer offers a selective advantage to different-colored males at different locations, the
populations will begin to mate more randomly and the distinct red and blue phenotypes will
become less common because environmental factors will no longer be favoring the selection
of these specific phenotypes and they will decrease in frequency in the population.
(B) Because the water is cloudy with silt, brown-colored cichlids will be favored by the females
and will have a selective advantage in both populations.
Page 8 of 9
PROCTOR VERSION
1.5 C: Role of the Environment in Evolution Quiz
Distractor Rationale:
This answer suggests the student may understand that brown phenotypes might increase
fitness because they provide camouflage in the new conditions, but does not understand
that females would not change to favor brown phenotypes because they have been selected
to favor males with brighter colors.
(C) Because the water is cloudy and the fish cannot see through the silt, the fish will lose both
their coloration and their ability to see, since neither trait will be needed for their survival.
Distractor Rationale:
This answer suggests the student may understand that when an environment changes,
adaptations such as coloration or vision may be lost if they no longer provide a selective
advantage, but does not understand that there is no evidence in this case to support the
fish losing their vision or all of their coloration and that it is more likely that the distinct red
and blue phenotypes will become less common because environmental factors will no
longer be favoring the selection of these specific phenotypes and they will decrease in
frequency in the population.
(D) Because the females at the bottom of the lake favor red males and the females near the top
of the lake favor blue males, the populations will remain unchanged due to female
preference being genetically determined.
Distractor Rationale:
This answer suggests the student may understand that many behaviors, such as mate
selection, are genetically determined, but does not understand that there would not be a
selective advantage for males having either blue or red coloration in cloudy water because
the light would not favor either phenotype in the new conditions.
Aligned to: LO 1.5 CA 1.5: Impact of Environment on Evolution
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