AP Bio Exam Practice Questions and
Answers13
Many species of corals are threatened by the increasing temperatures and decreasing pH of
ocean waters. One species, Stylophora pistillata, has been found to thrive in water that is
warmer and has a lower pH than the water that corals typically thrive in. Additionally,
researchers have found that the tolerance for the new water conditions is heritable. Which of
the following statements best explains the changes seen in S. pistillata in response to the
changing water conditions? - ANSWERS -The coralsʻ adaptation is an example of natural
selection because the tolerance is in response to a changing environment and has a genetic
basis.
A researcher measured the temperature at which two different samples of double-stranded
DNA denature (separate into single strands). Sample 1 denatured at a significantly lower
temperature than sample 2 did. Based on the data, the researcher claims that the DNA in
sample 2 is composed of a higher percentage of guanine and cytosine than the DNA in sample 1
is.
Which of the following best supports the researcher's claim? - ANSWERS -Guanine-cytosine
pairs denature at a higher temperature because they have more hydrogen bonds between them
than adenine-thymine pairs do.
Researchers studying the bacterium Escherichia coli split a population of the bacteria into two
samples.
Sample I was transformed with a plasmid containing a gene that makes the bacteria resistant to
the antibiotic kanamycin. Sample 2 was transformed with a plasmid lacking the antibiotic
resistance gene. A portion of each sample was then added to growth plates containing just
nutrients or growth plates containing nutrients and kanamycin.
After being allowed to grow for 24 hours at 37°C, the number of colonies on each growth plate
was counted
(Table 1).
, Which of the following claims is best supported by the data in Table 1? - ANSWERS -Only the
bacteria that were successfully transformed with the kanamycin resistance gene grew on
plate 4.
The fertilization of ovules from plant Q by pollen from plant R results in the production of seeds.
What percent of the genes in each offspring's chloroplasts will have been inherited from plant
R? - ANSWERS -0%
High levels of certain plant nutrients in runoff can lead to rapid growth of algae (an algal bloom)
in aquatic ecosystems. These algal blooms are generally followed by algal death and
decomposition, which consumes large amounts of dissolved oxygen in the water and results in
oxygen levels insufficient to support aerobic respiration.
This process is known as eutrophication. The amount of algae present in a body of water can be
estimated from the amount of chlorophyll a in a sample of the water. A researcher studying
eutrophication collected samples at different times of the year in a freshwater ecosystem. The
samples were analyzed for total nitrogen and chlorophyll a concentration (Figure I) as well as
total phosphorus and chlorophyll a concentration (Figure 2).
Which of the following best explains how higher concentrations of nitrogen and phosphorus
contribute to eutrophication? - ANSWERS -Algae require nitrogen and phosphorus to build
macromolecules, so higher concentrations of these nutrients can result in algal blooms.
Which of the following was the dependent
variable in the researcher's study? - ANSWERS -The concentration of chlorophyll a
Which of the following describes the
relationship between the amount of chlorophyll a in a water sample and the concentration of
nitrogen in that sample? - ANSWERS -The concentrations of nitrogen and chlorophyll a are
directly correlated.
Which of the following investigations would enable researchers to test the claim that an
increased concentration of algae has a negative effect on the number of aquatic invertebrates in
Answers13
Many species of corals are threatened by the increasing temperatures and decreasing pH of
ocean waters. One species, Stylophora pistillata, has been found to thrive in water that is
warmer and has a lower pH than the water that corals typically thrive in. Additionally,
researchers have found that the tolerance for the new water conditions is heritable. Which of
the following statements best explains the changes seen in S. pistillata in response to the
changing water conditions? - ANSWERS -The coralsʻ adaptation is an example of natural
selection because the tolerance is in response to a changing environment and has a genetic
basis.
A researcher measured the temperature at which two different samples of double-stranded
DNA denature (separate into single strands). Sample 1 denatured at a significantly lower
temperature than sample 2 did. Based on the data, the researcher claims that the DNA in
sample 2 is composed of a higher percentage of guanine and cytosine than the DNA in sample 1
is.
Which of the following best supports the researcher's claim? - ANSWERS -Guanine-cytosine
pairs denature at a higher temperature because they have more hydrogen bonds between them
than adenine-thymine pairs do.
Researchers studying the bacterium Escherichia coli split a population of the bacteria into two
samples.
Sample I was transformed with a plasmid containing a gene that makes the bacteria resistant to
the antibiotic kanamycin. Sample 2 was transformed with a plasmid lacking the antibiotic
resistance gene. A portion of each sample was then added to growth plates containing just
nutrients or growth plates containing nutrients and kanamycin.
After being allowed to grow for 24 hours at 37°C, the number of colonies on each growth plate
was counted
(Table 1).
, Which of the following claims is best supported by the data in Table 1? - ANSWERS -Only the
bacteria that were successfully transformed with the kanamycin resistance gene grew on
plate 4.
The fertilization of ovules from plant Q by pollen from plant R results in the production of seeds.
What percent of the genes in each offspring's chloroplasts will have been inherited from plant
R? - ANSWERS -0%
High levels of certain plant nutrients in runoff can lead to rapid growth of algae (an algal bloom)
in aquatic ecosystems. These algal blooms are generally followed by algal death and
decomposition, which consumes large amounts of dissolved oxygen in the water and results in
oxygen levels insufficient to support aerobic respiration.
This process is known as eutrophication. The amount of algae present in a body of water can be
estimated from the amount of chlorophyll a in a sample of the water. A researcher studying
eutrophication collected samples at different times of the year in a freshwater ecosystem. The
samples were analyzed for total nitrogen and chlorophyll a concentration (Figure I) as well as
total phosphorus and chlorophyll a concentration (Figure 2).
Which of the following best explains how higher concentrations of nitrogen and phosphorus
contribute to eutrophication? - ANSWERS -Algae require nitrogen and phosphorus to build
macromolecules, so higher concentrations of these nutrients can result in algal blooms.
Which of the following was the dependent
variable in the researcher's study? - ANSWERS -The concentration of chlorophyll a
Which of the following describes the
relationship between the amount of chlorophyll a in a water sample and the concentration of
nitrogen in that sample? - ANSWERS -The concentrations of nitrogen and chlorophyll a are
directly correlated.
Which of the following investigations would enable researchers to test the claim that an
increased concentration of algae has a negative effect on the number of aquatic invertebrates in
