AP BIOLOGY MULTIPLE CHOICE EXAM
QUESTIONS AND ANSWERS
To determine the evolutionary history and relationships among organisms, scientists
gather evidence from a wide variety of sources including paleontology, embryology,
morphology, behavior, and molecular biology. A phylogenetic tree of vertebrates is
shown. Which of the following statements is most consistent with the phylogenetic tree
shown?
A) Birds and turtles evolved their own means of gas exchange independently of the
other vertebrates.
B) Mammals are most closely related to birds because they share a direct common
ancestor.
C) The common ancestor of reptiles, birds, and mammals produced amniotic eggs.
D) Crocodiles are direct descendents of ray-finned fishes since they live in the same
environment. - Answer- C) The common ancestor of reptiles, birds, and mammals
produced amniotic eggs.
The diagram above depicts the response to a pinprick (stimulus) on the tip of a human
finger. The arrows show the direction of impulse transmission along the labeled axons.
If axon II was damaged before the pinprick, which of the following is most likely?
A) The person will not feel the pinprick.
B) The person can no longer feel pain.
C) The person's finger will not withdraw reflexively.
D) The person cannot transmit nerve impulses to the brain. - Answer- C) The person's
finger will not withdraw reflexively.
In the Arctic Ocean, the predominant primary producers are phytoplankton.
Phytoplankton are consumed by zooplankton, which in turn are eaten by codfish. In
years when there is more open water (less ice coverage), there are more zooplankton
and fish than in years with less open water (more ice coverage). Based on the graph
above, the difference is most likely because
A) when there is less open water, light is blocked from the zooplankton, so they cannot
produce as much food for the fish
B) when there is more open water, the
temperature is warmer, so the zooplankton and fish populations increase in size
C) the ice blocks the light, so in years with more ice coverage, there is less
photosynthesis by the phytoplankton
D) the ice increases the light available for photosynthesis, so primary production
increases and zooplankton populations increase in size - Answer- C) the ice blocks the
light, so in years with more ice coverage, there is less photosynthesis by the
phytoplankton
, The diagram above illustrates feedback control as exerted by the hormone thyroxine.
Following surgical removal of the thyroid gland, the level of TSH in the blood will
increase. Which of the following best explains this increase?
A) Residual blood thyroxine, from prior to thyroid gland removal, will bind to cells in the
anterior pituitary, signaling more TSH secretion.
B) Thyroxine will remain bound to thyroxine receptors on various body cells, and these
body cells will secrete additional hormones that stimulate the anterior pituitary to secrete
TSH.
C) Thyroxine that was stored in the anterior pituitary prior to thyroid gland removal will
signal more TSH secretion.
D) A decrease in thyroxine levels means a loss of inhibition to the hypothalamus and
anterior pituitary, leading to increased TSH secretion. - Answer- D) A decrease in
thyroxine levels means a loss of inhibition to the hypothalamus and anterior pituitary,
leading to increased TSH secretion.
Which of the following provides the best indication that light is required for the activation
of electron transfer reactions in chloroplasts?
A) Calculating the rate of change of the absorbance for sample 1
B) Comparing the observed results for sample 2 and sample 3
C) Repeating the entire experimental procedure at night
D) Including multiple trials for all the samples - Answer- B) Comparing the observed
results for sample 2 and sample 3
If the experiment was continued for an additional 500 days, the population density of T.
castaneum with the parasite would most likely stabilize at a value closest to which of the
following?
A) 5 beetles/culture dish
B) 10 beetles/culture dish
C) 20 beetles/culture dish
D) 25 beetles/culture dish - Answer- B) 10 beetles/culture dish
The vertebrate forelimb initially develops in the embryo as a solid mass of tissue. As
development progresses, the solid mass near the end of the forelimb is remodeled into
individual digits. Which of the following best explains the role of apoptosis in remodeling
of the forelimb?
A) Apoptosis replaces old cells with new ones that are less likely to contain mutations.
B) Apoptosis involves the regulated activation of proteins in specific cells of the
developing
forelimb that leads to the death of those cells.
C) Apoptosis involves the destruction of extra cells in the developing forelimb, which
provides nutrients for phagocytic cells.
D) Apoptosis in the developing forelimb triggers the differentiation of cells whose fate
was
not already determined. - Answer- B) Apoptosis involves the regulated activation of
proteins in specific cells of the developing
QUESTIONS AND ANSWERS
To determine the evolutionary history and relationships among organisms, scientists
gather evidence from a wide variety of sources including paleontology, embryology,
morphology, behavior, and molecular biology. A phylogenetic tree of vertebrates is
shown. Which of the following statements is most consistent with the phylogenetic tree
shown?
A) Birds and turtles evolved their own means of gas exchange independently of the
other vertebrates.
B) Mammals are most closely related to birds because they share a direct common
ancestor.
C) The common ancestor of reptiles, birds, and mammals produced amniotic eggs.
D) Crocodiles are direct descendents of ray-finned fishes since they live in the same
environment. - Answer- C) The common ancestor of reptiles, birds, and mammals
produced amniotic eggs.
The diagram above depicts the response to a pinprick (stimulus) on the tip of a human
finger. The arrows show the direction of impulse transmission along the labeled axons.
If axon II was damaged before the pinprick, which of the following is most likely?
A) The person will not feel the pinprick.
B) The person can no longer feel pain.
C) The person's finger will not withdraw reflexively.
D) The person cannot transmit nerve impulses to the brain. - Answer- C) The person's
finger will not withdraw reflexively.
In the Arctic Ocean, the predominant primary producers are phytoplankton.
Phytoplankton are consumed by zooplankton, which in turn are eaten by codfish. In
years when there is more open water (less ice coverage), there are more zooplankton
and fish than in years with less open water (more ice coverage). Based on the graph
above, the difference is most likely because
A) when there is less open water, light is blocked from the zooplankton, so they cannot
produce as much food for the fish
B) when there is more open water, the
temperature is warmer, so the zooplankton and fish populations increase in size
C) the ice blocks the light, so in years with more ice coverage, there is less
photosynthesis by the phytoplankton
D) the ice increases the light available for photosynthesis, so primary production
increases and zooplankton populations increase in size - Answer- C) the ice blocks the
light, so in years with more ice coverage, there is less photosynthesis by the
phytoplankton
, The diagram above illustrates feedback control as exerted by the hormone thyroxine.
Following surgical removal of the thyroid gland, the level of TSH in the blood will
increase. Which of the following best explains this increase?
A) Residual blood thyroxine, from prior to thyroid gland removal, will bind to cells in the
anterior pituitary, signaling more TSH secretion.
B) Thyroxine will remain bound to thyroxine receptors on various body cells, and these
body cells will secrete additional hormones that stimulate the anterior pituitary to secrete
TSH.
C) Thyroxine that was stored in the anterior pituitary prior to thyroid gland removal will
signal more TSH secretion.
D) A decrease in thyroxine levels means a loss of inhibition to the hypothalamus and
anterior pituitary, leading to increased TSH secretion. - Answer- D) A decrease in
thyroxine levels means a loss of inhibition to the hypothalamus and anterior pituitary,
leading to increased TSH secretion.
Which of the following provides the best indication that light is required for the activation
of electron transfer reactions in chloroplasts?
A) Calculating the rate of change of the absorbance for sample 1
B) Comparing the observed results for sample 2 and sample 3
C) Repeating the entire experimental procedure at night
D) Including multiple trials for all the samples - Answer- B) Comparing the observed
results for sample 2 and sample 3
If the experiment was continued for an additional 500 days, the population density of T.
castaneum with the parasite would most likely stabilize at a value closest to which of the
following?
A) 5 beetles/culture dish
B) 10 beetles/culture dish
C) 20 beetles/culture dish
D) 25 beetles/culture dish - Answer- B) 10 beetles/culture dish
The vertebrate forelimb initially develops in the embryo as a solid mass of tissue. As
development progresses, the solid mass near the end of the forelimb is remodeled into
individual digits. Which of the following best explains the role of apoptosis in remodeling
of the forelimb?
A) Apoptosis replaces old cells with new ones that are less likely to contain mutations.
B) Apoptosis involves the regulated activation of proteins in specific cells of the
developing
forelimb that leads to the death of those cells.
C) Apoptosis involves the destruction of extra cells in the developing forelimb, which
provides nutrients for phagocytic cells.
D) Apoptosis in the developing forelimb triggers the differentiation of cells whose fate
was
not already determined. - Answer- B) Apoptosis involves the regulated activation of
proteins in specific cells of the developing
