BIOB51 SAMPLE QS EXAM
QUESTIONS WITH CORRECT
ANSWERS
The condition that occurs when a mutation that causes beneficial effects for one trait
also causes detrimental effects on other traits is called
A. pleiotropy.
B. positive selection.
C. negative selection.
D. antagonistic pleiotropy. - Answer- ANS: D
antagonistic pleiotropy
The medium ground finches on Daphne Major were affected by drought in 1977. Which
statement do the data in the figures support?
A. Natural selection caused a shift toward larger beaks after the drought.
B. Small-beaked birds tend to produce chicks with small beaks.
C. Natural selection caused a shift toward smaller beaks after the drought.
D. Large beaks cannot be inherited, although they help birds survive drought.
(LEC 15 SLIDE 5) - Answer- ANS: A
Natural selection caused a shift toward larger beaks after the drought.
Which statement do the data in the figure support?
A. Blending into the background could decrease fitness in mice.
B. Contrasting with the background could increase fitness in mice.
C. Blending into the background could increase fitness in mice.
D. Fur color does not confer a fitness benefit to either inland or beach mouse
populations - Answer- ANS: C
Blending into the background could increase fitness in mice.
Which statement describes the evolutionary history of winter-brown snowshoe hares in
Washington?
A. Their entire genome suggests they are in a clade with black-tailed jackrabbits and
acquired the Agouti gene from winter-white hares.
B. They have a mutation for winter-brown fur that occurred in the Agouti gene of a
winter-white hare and persisted where it increased fitness.
C. They descended from winter-white hares and acquired the Agouti allele for winter-
brown fur from randomly mating with black-tailed jackrabbits.
, D. They are infertile hybrids produced by mating between winter-white hares and black-
tailed jackrabbits, which contribute the Agouti allele. - Answer- ANS: C
They descended from winter-white hares and acquired the Agouti allele for winter-brown
fur from randomly mating with black-tailed jackrabbits.
What type of selection occurs when one extreme of a phenotypic range is favored?
A. directional selection
B. stabilizing selection
C. disruptiveselection
D. sexual selection - Answer- ANS: A
Directional Selection
Why do three-spined stickleback fish with low-Eda (L) alleles have an advantage in
freshwater over sticklebacks with high-Eda (C) alleles? (Less predators in freshwater)
A. Low-Eda fish stop growing at smaller body sizes, which allows them to survive with
less armor.
B. Low-Eda fish use their available energy to grow faster and add body mass instead of
armor.
C. Low-Eda fish can grow heavier armor to defend against the predators in freshwater.
D. Low-Eda fish can produce both large bodies and heavy armor when food is
abundant. - Answer- ANS B
Low-Eda fish use their available energy to grow faster and add body mass instead of
armor.
According to the twofold cost of sex, natural selection should favor the evolution of
asexual reproduction for all of the following reasons EXCEPT
A. asexual reproduction can take place without a genetic contribution from a male.
B. a sexual offspring are genetically identical to their parents.
C. asexual populations grow more rapidly than sexually reproducing populations.
D. all asexual individuals are capable of producing offspring - Answer- ANS B
a sexual offspring are genetically identical to their parents.
How does sex release populations from Muller's ratchet?
A. Recombination shuffles the alleles of one parent to produce offspring with that
parent's beneficial alleles.
B. Closely related parents may each contribute the same deleterious mutations to their
offspring.
C. Beneficial mutations pass to offspring, which increases the genetic load of the
offspring.
D. Since each parent contributes half their alleles, some deleterious alleles may not be
passed to offspring. - Answer- ANS D
QUESTIONS WITH CORRECT
ANSWERS
The condition that occurs when a mutation that causes beneficial effects for one trait
also causes detrimental effects on other traits is called
A. pleiotropy.
B. positive selection.
C. negative selection.
D. antagonistic pleiotropy. - Answer- ANS: D
antagonistic pleiotropy
The medium ground finches on Daphne Major were affected by drought in 1977. Which
statement do the data in the figures support?
A. Natural selection caused a shift toward larger beaks after the drought.
B. Small-beaked birds tend to produce chicks with small beaks.
C. Natural selection caused a shift toward smaller beaks after the drought.
D. Large beaks cannot be inherited, although they help birds survive drought.
(LEC 15 SLIDE 5) - Answer- ANS: A
Natural selection caused a shift toward larger beaks after the drought.
Which statement do the data in the figure support?
A. Blending into the background could decrease fitness in mice.
B. Contrasting with the background could increase fitness in mice.
C. Blending into the background could increase fitness in mice.
D. Fur color does not confer a fitness benefit to either inland or beach mouse
populations - Answer- ANS: C
Blending into the background could increase fitness in mice.
Which statement describes the evolutionary history of winter-brown snowshoe hares in
Washington?
A. Their entire genome suggests they are in a clade with black-tailed jackrabbits and
acquired the Agouti gene from winter-white hares.
B. They have a mutation for winter-brown fur that occurred in the Agouti gene of a
winter-white hare and persisted where it increased fitness.
C. They descended from winter-white hares and acquired the Agouti allele for winter-
brown fur from randomly mating with black-tailed jackrabbits.
, D. They are infertile hybrids produced by mating between winter-white hares and black-
tailed jackrabbits, which contribute the Agouti allele. - Answer- ANS: C
They descended from winter-white hares and acquired the Agouti allele for winter-brown
fur from randomly mating with black-tailed jackrabbits.
What type of selection occurs when one extreme of a phenotypic range is favored?
A. directional selection
B. stabilizing selection
C. disruptiveselection
D. sexual selection - Answer- ANS: A
Directional Selection
Why do three-spined stickleback fish with low-Eda (L) alleles have an advantage in
freshwater over sticklebacks with high-Eda (C) alleles? (Less predators in freshwater)
A. Low-Eda fish stop growing at smaller body sizes, which allows them to survive with
less armor.
B. Low-Eda fish use their available energy to grow faster and add body mass instead of
armor.
C. Low-Eda fish can grow heavier armor to defend against the predators in freshwater.
D. Low-Eda fish can produce both large bodies and heavy armor when food is
abundant. - Answer- ANS B
Low-Eda fish use their available energy to grow faster and add body mass instead of
armor.
According to the twofold cost of sex, natural selection should favor the evolution of
asexual reproduction for all of the following reasons EXCEPT
A. asexual reproduction can take place without a genetic contribution from a male.
B. a sexual offspring are genetically identical to their parents.
C. asexual populations grow more rapidly than sexually reproducing populations.
D. all asexual individuals are capable of producing offspring - Answer- ANS B
a sexual offspring are genetically identical to their parents.
How does sex release populations from Muller's ratchet?
A. Recombination shuffles the alleles of one parent to produce offspring with that
parent's beneficial alleles.
B. Closely related parents may each contribute the same deleterious mutations to their
offspring.
C. Beneficial mutations pass to offspring, which increases the genetic load of the
offspring.
D. Since each parent contributes half their alleles, some deleterious alleles may not be
passed to offspring. - Answer- ANS D
