The fact that all seven of the pea plant traits studied by Mendel obeyed the principle of
independent assortment most probably indicates which of the following?
A) None of the traits obeyed the law of segregation.
B) The diploid number of chromosomes in the pea plants was 7.
C) All of the genes controlling the traits were located on the same chromosome.
D) All of the genes controlling the traits behaved as if they were on different
chromosomes.
Which statement is most consistent with the hypothesis that the Cambrian explosion
was caused by the rise of predator-prey relationships? The fossil record reveals an
increased incidence of _____.
A) worm burrows
B) larger animals
C) organic material
D) hard parts
Use the following description to answer the question(s) below.
On the Bahamian island of Andros, mosquitofish populations live in various,
now-isolated, freshwater ponds that were once united. Currently, some predator-rich
ponds have mosquitofish that can swim in short, fast bursts; other predator-poor ponds
have mosquitofish that can swim continuously for a long time. When placed together in
the same body of water, the two kinds of female mosquitofish exhibit exclusive
breeding preferences.
If one builds a canal linking a predator-rich pond to a predator-poor pond, then what
type(s) of selection should subsequently be most expected among the mosquitofish in
the original predator-rich pond, and what type(s) should be most expected among the
mosquitofish in the formerly predator-poor pond?
A) stabilizing selection; directional selection
B) stabilizing selection; stabilizing selection
C) less-intense directional selection; more-intense directional selection
D) less-intense disruptive selection; more-intense disruptive selection
Brown-headed cowbirds utilize fragmented forests effectively by _____.
A) feeding on the fruits of shrubs that tend to grow at the forest/open-field interface
B) parasitizing the nests of forest birds and feeding on open-field insects
C) roosting in forest trees and nesting in grassy fields
D) outcompeting other songbird species for access to nesting holes in old-growth trees
Which of the groups shown above is a functional group that helps stabilize proteins by
forming covalent cross-links within or between protein molecules?
A) A
B) B
C) C
D) D
Marfan syndrome in humans is caused by an abnormality of the connective tissue
protein fibrillin. Patients are usually very tall and thin, with long spindly fingers,
curvature of the spine, sometimes weakened arterial walls, and sometimes ocular
problems, such as lens dislocation. Which of the following would you conclude about
Marfan syndrome from this information?
A) It is recessive.
B) It is dominant.
C) It is pleiotropic.
D) It is epistatic.
In the figure above, which number would designate the arctic tundra biome?
A) 2
B) 3
C) 4
D) 5
If a viral host cell has a mutation that interferes with the addition of carbohydrates to
proteins in the Golgi, which of the following could likely result?
A) The viral envelope proteins would not be glycosylated and might not arrive at the
host plasma membrane.
B) The viral capsid proteins would not be glycosylated and might not arrive at the host
plasma membrane.
C) The viral core proteins would not be glycosylated and might not arrive at the host
plasma membrane.
D) The virus would be unable to reproduce within the host cell.
Which of the following is true of the life cycle of mosses?
A) The haploid generation grows on the sporophyte generation.
B) Spores are primarily distributed by water currents.
C) Antheridia and archegonia are produced by gametophytes.
D) The sporophyte generation is dominant.
Which of these conditions are always true of populations evolving due to natural
selection?
Condition 1: The population must vary in traits that are heritable.
Condition 2: Some heritable traits must increase reproductive success.
Condition 3: Individuals pass on most traits that they acquire during their lifetime.
A) Condition 1 only
B) Condition 2 only
C) Conditions 1 and 2
D) Conditions 2 and 3
Several tomato plants are growing in a small garden plot. If soil water potential were to
drop significantly on a hot, summer afternoon, which of the following would most
likely occur?
A) Size of stomatal openings would decrease.
B) Transpiration would increase.
C) The leaves would become more turgid.
D) The uptake of carbon dioxide would be enhanced.
In a plant’s sexual life cycle _____.
A) sporophytes produce gametes by meiosis
B) gametophytes produce gametes by mitosis
C) gametophytes produce gametes by meiosis
D) sporophytes produce gametes by mitosis
The following is a map of four genes on a chromosome.
Between which two genes would you expect the highest frequency of recombination?
A) A and W
B) E and G
C) A and E
D) A and G
People with type II diabetes mellitus have defective insulin receptors that cannot
respond to insulin properly. Relative to normal individuals, what would be the effect on
blood glucose levels under conditions of chronic stress that kept blood cortisol levels
high? There would be _____.
A) a greater increase in blood glucose levels in individuals with type II diabetes
mellitus than in normal individuals
B) less increase in blood glucose levels in individuals with type II diabetes mellitus
than in normal individuals
C) be a greater decrease in blood glucose levels in individuals with type II diabetes
mellitus than in normal individuals
D) less decrease in blood glucose levels in individuals with type II diabetes mellitus
than in normal individuals
Use the following information when answering the corresponding question(s).
In 1668, Francesco Redi performed a series of experiments on spontaneous generation.
He began by putting similar pieces of meat into eight identical jars. Four jars were left
open to the air, and four were sealed. He then did the same experiment with one
variation: Instead of sealing four of the jars completely, he covered them with gauze
(the gauze excluded the flies while allowing the meat to be exposed to air). In both
experiments, he monitored the jars and recorded whether or not maggots (young flies)
appeared in the meat.
Refer to the paragraph on Redi’s experiments. What hypothesis was being tested in the
initial experiment with open versus sealed jars?
A) Spontaneous generation is more likely during the long days of summer.
B) The type of meat used affects the likelihood of spontaneous generation.
C) Maggots do not arise spontaneously, but from eggs laid by adult flies.
D) Spontaneous generation can occur only if meat is exposed to air.
An example of a properly functioning homeostatic control system is seen when _____.
A) the core body temperature of a runner rises gradually from 37C to 45C
B) the kidneys excrete salt into the urine when dietary salt levels rise
C) a blood cell shrinks when placed in a solution of salt and water
D) the blood pressure increases in response to an increase in blood volume
The fastest possible conduction velocity of action potentials is observed in _____.
A) thin, non-myelinated neurons
B) thin, myelinated neurons
C) thick, non-myelinated neurons
D) thick, myelinated neurons
Use the following information to answer the questions below.
Succinate dehydrogenase catalyzes the conversion of succinate to fumarate. The
reaction is inhibited by malonic acid, which resembles succinate but cannot be acted
upon by succinate dehydrogenase. Increasing the ratio of succinate to malonic acid
reduces the inhibitory effect of malonic acid.
HIV is the virus that causes AIDS. In the mid-1990s, researchers discovered an enzyme
in HIV called protease. Once the enzyme’s structure was known, researchers began
looking for drugs that would fit into the active site and block it. If this strategy for
stopping HIV infections were successful, it would be an example of what phenomenon?
A) vaccination
B) denaturation
C) allosteric regulation
D) competitive inhibition
What would be the consequences if we were to reverse the direction of water flow over
the gills of a fish, moving water inward past the operculum, past the gills, the out the
mouth? This reversal of water flow would _____.
A) reduce efficiency of gas exchange
B) change the exchange of gases in the body from carbon dioxide out and oxygen in to
carbon dioxide in and oxygen out
C) increase the efficiency of gas exchange
During the inventory of bacterial genes present in the Sargasso Sea in the middle of the
Atlantic Ocean, a research team concluded that at least 1800 bacterial species were
discovered. Based on what you know about this area, what would you expect to see in
coral reef waters?
A) slightly greater genetic diversity
B) slightly smaller genetic diversity
C) markedly greater genetic diversity
D) markedly smaller genetic diversity
Action potentials move along axons _____.
A) more slowly in axons of large than in small diameter
B) by activating the sodium-potassium “pump” at each point along the axonal
membrane
C) more rapidly in myelinated than in non-myelinated axons
D) by reversing the concentration gradients for sodium and potassium ions
Suppose you are studying the nitrogen cycling in a pond ecosystem over the course of a
month. While you are collecting data, a flock of one hundred Canada geese lands and
spends the night during a fall migration. What could you do to eliminate error in your
study as a result of this event?
A) Find out how much nitrogen is consumed in plant material by a Canada goose over
about a twelve-hour period, multiply this number by 100, and add that amount to the
total nitrogen in the ecosystem.
B) Find out how much nitrogen is eliminated by a Canada goose over about a
twelve-hour period, multiply this number by 100, and subtract that amount from the
total nitrogen in the ecosystem.
C) Find out how much nitrogen is consumed and eliminated by a Canada goose over
about a twelve-hour period and multiply this number by 100; enter this +/- value into
the nitrogen budget of the ecosystem.
D) Put a net over the pond so that no more migrating flocks can land on the pond and
alter the nitrogen balance of the pond.
If an ovary contains 50 ovules, what is the minimum number of pollen grains that must
land to form 50 mature seeds?
A) 25
B) 50
C) 100
D) 500
For the following questions, match the key event of meiosis with the stages listed
below.
Homologous chromosomes are aligned at the equator of the spindle.
A) I
B) II
C) IV
D) VI
Carbon-12 is the most common isotope of carbon and has a mass number of 12.
However, the average atomic mass of carbon found on a periodic table is slightly more
than 12 daltons. Why?
A) The atomic mass does not include the mass of electrons.
B) Some carbon atoms in nature have an extra proton.
C) Some carbon atoms in nature have more neutrons.
D) Some carbon atoms in nature have a different valence electron distribution.
The laying of eggs has what type of analog in angiosperms?
A) endosperm breakdown
B) fusion of carpels into a fruit
C) fruit dispersal
D) seed coat hardening
Which of the following organisms is INCORRECTLY paired with its trophic level?
A) cyanobacterium primary producer
B) grasshopper primary consumer
C) zooplankton primary producer
D) fungus detritivore
Adherence to the intestinal lining by this bacterium is due to its possession of _____.
A) fimbriae
B) pili
C) a capsule
D) a flagellum
Which of the following is a correct statement about sugar movement in phloem?
A) Diffusion can account for the observed rates of transport.
B) Movement can occur both upward and downward in the plant.
C) Sugar is translocated from sinks to sources.
D) Only phloem cells with nuclei can perform sugar movement.
The following questions refer to the evolutionary tree in the figure below.
The horizontal axis of the cladogram depicted below is a timeline that extends from
100,000 years ago to the present; the vertical axis represents nothing in particular. The
labeled branch points on the tree (V-Z) represent various common ancestors. Let’s say
that only since 50,000 years ago has there been enough variation between the lineages
depicted here to separate them into distinct species, and only the tips of the lineages on
this tree represent distinct species.
Which of the five common ancestors, labeled V-Z, is the common ancestor of the
greatest number of species, both living and extinct?
A) V
B) W
C) Y
D) Z
In E. coli, what is the function of DNA polymerase III?
A) to unwind the DNA helix during replication
B) to seal together the broken ends of DNA strands
C) to add nucleotides to the end of a growing DNA strand
D) to degrade damaged DNA molecules
Rocky Mountain juniper (Juniperus scopulorum) and one-seeded juniper (J.
monosperma) have overlapping ranges. Pollen grains (which contain sperm cells) from
one species are unable to germinate and make pollen tubes on female ovules (which
contain egg cells) of the other species. These two juniper species are kept separate by
_____.
A) habitat isolation
B) temporal isolation
C) gametic isolation
D) behavioral isolation