During a field trip, an instructor touched a moth resting on a tree trunk. The moth raised
its forewings to reveal large eyespots on its hind wings. The instructor asked why the
moth lifted its wings. One student answered that sensory receptors had fired and
triggered a neuronal reflex culminating in the contraction of certain muscles. A second
student responded that the behavior might frighten predators. Which statement best
describes these explanations?
A) The first explanation is correct, but the second is incorrect.
B) The first explanation refers to proximate causation, whereas the second refers to
ultimate causation.
C) The first explanation is testable as a scientific hypothesis, whereas the second is not.
D) Both explanations are reasonable and simply represent a difference of opinion.
Which of the following DNA mutations is most likely to damage the protein it
specifies?
A) a base-pair deletion
B) an addition of three nucleotides
C) a substitution in the last base of a codon
D) a codon deletion
Wernicke’s and Broca’s regions of the brain affect _____.
A) olfaction
B) vision
C) speech
D) hearing
Researchers tried to explain how vesicular transport occurs in cells by attempting to
assemble the transport components. They set up microtubular tracks along which
vesicles could be transported, and they added vesicles and ATP (because they knew the
transport process requires energy). Yet, when they put everything together, there was no
movement or transport of vesicles. What were they missing?
A) an axon
B) contractile microfilaments
C) endoplasmic reticulum
D) motor proteins
The sun shining on a tidal pool during a hot day heats the water. As some water
evaporates, the pool becomes saltier, causing _____.
A) an increase in its carbon dioxide content
B) a decrease in its oxygen content
C) an increase in its ability to sustain aerobic organisms
D) a decrease in the water’s density
Food web for a particular terrestrial ecosystem
(arrows represent energy flow and letters represent species)
Examine this food web for a particular terrestrial ecosystem. Which pair of species
could be omnivores?
A) A and D
B) B and C
C) C and D
D) C and E
A large seaweed that floats freely on the surface of deep bodies of water would be
expected to lack which of the following?
A) thalli
B) bladders
C) holdfasts
D) gel-forming polysaccharides
In the mid-1900s, the Soviet geneticist Lysenko believed that his winter wheat plants,
exposed to increasingly colder temperatures, would eventually give rise to more
cold-tolerant winter wheat. Lysenko’s attempts in this regard were most in agreement
with the ideas of _____.
A) Cuvier
B) Lamarck
C) Darwin
D) Lyell
A hybrid zone is properly defined as _____.
A) an area where the ranges of two closely related species overlap, but do not
interbreed
B) an area where mating occurs between members of two closely related species,
producing viable offspring
C) a zone where sterile hybrids form, kept separate by postzygotic barriers
D) an area where members of two closely related species intermingle, but gene flow is
prevented by prezygotic barriers
Regarding these sequence homology data, the principle of maximum parsimony would
be applicable in _____.
A) distinguishing introns from exons
B) determining degree of sequence homology
C) selecting appropriate genes for comparison among species
D) inferring evolutionary relatedness from the number of sequence differences
You and a friend were in line for a movie when you noticed the woman in front of you
sneezing and coughing. Both of you were equally exposed to the woman’s virus, but
over the next few days, only your friend acquired flu-like symptoms and was ill for
almost a week before recovering. Which one of the following is a logical explanation
for this?
A) Your friend had antibodies to that virus.
B) You had an adaptive immunity to that virus.
C) Your friend had an autoimmune disorder.
D) Your friend had allergies.
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 species, labeled V-Z, is the common ancestor of the fewest number of
species?
A) V
B) W
C) Y
D) Z
Which of the following statements is representative of the second law of
thermodynamics?
A) Conversion of energy from one form to another is always accompanied by some
gain of free energy.
B) Without an input of energy, organisms would tend toward decreasing entropy.
C) Cells require a constant input of energy to maintain their high level of organization.
D) Every energy transformation by a cell decreases the entropy of the universe.
Let us suppose that someone is successful at producing induced pluripotent stem cells
(iPS) for replacement of pancreatic insulin-producing cells for people with type 1
diabetes. Which of the following could still be problems?
I. the possibility that, once introduced into the patient, the iPS cells produce
nonpancreatic cells
II. the failure of the iPS cells to take up residence in the pancreas
III. the inability of the iPS cells to respond to appropriate regulatory signals
A) I only
B) II only
C) III only
D) I, II, and III
For the following questions, match the labeled component of the cell membrane in
the figure with its description.
Which component is a glycolipid?
A) A
B) B
C) C
D) E
Scientists have found that extracellular matrix components may induce specific gene
expression in embryonic tissues such as the liver and testes. For this to happen there
must be direct communication between the extracellular matrix and the developing
cells. Which kind of transmembrane protein would most likely be involved in this kind
of induction?
A) integrins
B) collagens
C) actins
D) fibronectins
Epiphytes are _____.
A) aerial vines common in tropical regions
B) plants that live in poor soil and digest insects to obtain nitrogen
C) plants that grow on other plants but do not obtain nutrients from their hosts
D) plants that have a symbiotic relationship with fungi
Which of the following is true of metabolism in its entirety in all organisms?
A) Metabolism depends on a constant supply of energy from food.
B) Metabolism uses all of an organism’s resources.
C) Metabolism consists of all the energy transformation reactions in an organism.
D) Metabolism manages the increase of entropy in an organism.
Why is it so important to be able to amplify DNA fragments when studying genes?
A) Before amplification, DNA fragments are likely to bind to RNA and no longer be
able to be analyzed.
B) A gene may represent only a millionth of the cell’s DNA.
C) Restriction enzymes (endonucleases) cut DNA into fragments that are too small.
D) A clone requires multiple copies of each gene per clone.
Some animals have no gills when young, but then develop gills that grow larger as the
animal grows larger. What is the reason for this increase in gill size?
A) The young of these animals are much more active than the adult, which leads to a
higher BMR (basal metabolic rate) and, therefore, a higher need for oxygen.
B) Relative to their volume, the young have more surface area across which they can
transport all the oxygen they need.
C) The young have a higher basal metabolic rate.
D) Relative to their surface area, the young have more body volume in which they can
store oxygen for long periods of time.
Which of the following best describes a model organism?
A) It is often pictured in textbooks and easy for students to imagine.
B) It is well studied, it is easy to grow, and results are widely applicable.
C) It is small, inexpensive to raise, and lives a long time.
D) It has been chosen for study by early biologists.
Other than predation by introduced Nile perch, the most likely explanation for the
recent decline in cichlid species diversity in Lake Victoria is _____.
A) reinforcement
B) fusion
C) stability
D) polyploidy
Which of the following factors, when used to label the horizontal axis of the graph
above, would account most directly for the shape of the plot?
A) rate of cribrostatin synthesis (molecules/unit time)
B) number of pores per sponge
C) number of spicules per sponge
D) number of choanocytes per sponge
Animals that consume Brazil nuts derive nutrition mostly from tissue whose nuclei
have how many chromosomes?
A) 17
B) 34
C) 51
D) 68
If a patient is missing B and T cells, what would be absent from the immune response?
A) memory
B) lysozymes
C) cytokines
D) defense against bacteria
What does a frequency of recombination of 50% indicate?
A) The two genes are likely to be located on different chromosomes.
B) All of the offspring have combinations of traits that match one of the two parents.
C) The genes are located on sex chromosomes.
D) Abnormal meiosis has occurred.
Use the following information to answer the question(s) below.
Paulinella chromatophora is one of the few cercozoans that is autotrophic, carrying out
aerobic photosynthesis with its two elongated “chromatophores.” The chromatophores
are contained within vesicles of the host cell, and each is derived from a
cyanobacterium, though not the same type of cyanobacterium that gave rise to the
chloroplasts of algae and plants.
Which of the following groups is matched with a correct anatomical feature?
A) foraminifera → silicon-rich tests
B) dinoflagellata → holdfast
C) diatoms → tests made of cellulose
D) phaeophyta (brown algae) → blade
A researcher has developed two stains for use with seed plants. One stains sporophyte
tissue blue; the other stains gametophyte tissue red. If the researcher exposes pollen
grains to both stains, and then rinses away the excess stain, what should occur?
A) The pollen grains will be pure red.
B) The pollen grains will be pure blue.
C) The pollen grains will have red interiors and blue exteriors.
D) The pollen grains will have blue interiors and red exteriors.
Behaviors are diverse and important for survival and reproduction. Some behaviors are
learned, such as the species-specific song of a yellow warbler which is different from
the song of a blue-winged warbler. Other behaviors are innate, such as a female cat in
heat urinating more often and in many places to attract a mate or honeybees do a
“dance” that indicates the distance and direction of a food source when they return to
their hive. Which of the following statements supports the idea that behaviors are
important in survival and therefore affect natural selection?
A) Learned behaviors may not necessarily increase fitness. Baby warblers can learn the
song of another species.
B) Innate behaviors are the result of selection for individual survival and reproductive
success.
C) All behaviors are survival mechanisms that increase reproductive fitness by
increasing mutation rates.
D) Both innate and learned behaviors are entirely based on genes inherited from
parents.
Considering its total area covered, which ecosystem type represented in the figure
above has a very low level of economic impact on Earth’s ecosystem?
A) tropical wet forest
B) rock, sand, and ice
C) tropical seasonal forest
D) ocean neritic zone
Which of the following occur during the formation of an embryo from a zygote in
angiosperms?
I) The root and shoot systems emerge from the seed.
II) Basal cells form a connection between the parent plant and the developing embryo.
III) Meiosis produces a mass of cells that become the young embryo.
IV) Cells differentiate to form the basic plant tissue types.
V) The early root-shoot axis is formed.
A) I, II, and III
B) II, IV, and V
C) II, III, IV, and V
D) III, IV, and V
Why is nitrogen fixation an essential process?
A) Nitrogen fixation can only be done by certain prokaryotes.
B) Fixed nitrogen is often the limiting factor in plant growth.
C) Nitrogen fixation is very expensive in terms of metabolic energy.
D) Nitrogen fixers are sometimes symbiotic with legumes.
An inhibitory postsynaptic potential (IPSP) occurs in a membrane made more
permeable to _____.
A) potassium ions
B) sodium ions
C) ATP
D) all neurotransmitter molecules
Mature human sperm and ova are similar in that they _____.
A) both have the same number of chromosomes
B) are approximately the same size
C) each have a flagellum that provides motility
D) are produced from puberty until death