A plant developed a mineral deficiency after being treated with a fungicide. What is the
most probable cause of the deficiency?
A) Mineral receptor proteins in the plant membrane were not functioning.
B) Mycorrhizal fungi were killed.
C) Active transport of minerals was inhibited.
D) The genes for the synthesis of transport proteins were destroyed.
In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the
frequency of the allele a is 0.3. What is the frequency of individuals that are
homozygous for this allele?
A) 0.09
B) 0.49
C) 0.9
D) 9.0
The teacher and class were especially saddened when the colonial hydrozoan died.
They had watched it carefully, and the unfortunate creature never even got to produce
offspring by budding. Yet, everyone was elated when one of the students noticed a
small colonial hydrozoan growing in a part of the tank far from the location of the
original colony. The teacher was apparently unaware that these hydrozoans exhibit
_____.
A) spontaneous generation
B) abiogenesis
C) alternation of generations
D) a medusa stage
Use the following information to answer the question(s) below.
Suzanne Simard and colleagues knew that the same mycorrhizal fungal species could
colonize multiple types of trees. They wondered if the same fungal individual would
colonize different trees, forming an underground network that potentially could
transport carbon and nutrients from one tree to another (S. Simard et al. 1997. Net
transfer of carbon between mycorrhizal tree species in the field. Nature 388:579-82).
Figure A illustrates the team’s experimental setup. Pots containing seedlings of three
different tree species were set up and grown under natural conditions for three years;
two of the three species (Douglas fir, birch) formed ectomycorrhizae and the other
(cedar) formed arbuscular mycorrhizae. For the experiment, the researchers placed
airtight bags over the Douglas fir and birch seedlings; into each bag, they injected either
carbon dioxide made from carbon-13 or carbon-14 (13CO2 and 14CO2, isotopes of
carbon). As the seedlings photosynthesized, the radioactive carbon dioxide was
converted into radioactively labeled sugars that could be tracked and measured by the
researchers.
Based on the idea that fungi have pores between their cell walls, which allow cytoplasm
to move from one end of the mycelium to the other, which of the following hypotheses
is the most plausible?
A) If a single mycorrhizal fungus formed symbiotic associations with more than one
tree, carbon could travel from one plant to another.
B) Parasitic fungi steal nutrients from their hosts.
C) Predatory fungi capture their prey by encircling them with hyphae, and the flowing
of the cytoplasm through the pores helps the hyphae to move around the prey.
D) Fungi function as part of the global carbon cycle not only by converting carbon from
one form to another, but by physically moving it from one location to another.
You have a small tree in your yard that is the height that you want it, but does not have
as many branches as you want. How can you prune it to trigger it to increase the
number of branches?
A) Cut off the leaves at the ends of several branches.
B) Cut off the tips of the main shoots.
C) Cut off lower branches.
D) Cut off the leaves at the base of most of the branches.
Assuming that each of these possesses a cell wall, which prokaryotes should be
expected to be most strongly resistant to plasmolysis in hypertonic environments?
A) extreme halophiles
B) extreme thermophiles
C) methanogens
D) cyanobacteria
Males are more often affected by sex-linked traits than females because _____.
A) male hormones such as testosterone often alter the effects of mutations on the X
chromosome
B) female hormones such as estrogen often compensate for the effects of mutations on
the X chromosome
C) X chromosomes in males generally have more mutations than X chromosomes in
females
D) males are hemizygous for the X chromosome
Scientists isolate cells in various phases of the cell cycle. They find a group of cells that
have times more DNA than G1 phase cells. The cells of this group are _____.
A) between the G1 and S phases in the cell cycle
B) in the G2 phase of the cell cycle
C) in the M phase of the cell cycle
D) in the S phase of the cell cycle
Myelinated neurons are especially abundant in the _____.
A) gray matter of the brain and the white matter of the spinal cord
B) white matter of the brain and the gray matter of the spinal cord
C) gray matter of the brain and the gray matter of the spinal cord
D) white matter in the brain and the white matter in the spinal cord
Which of the following is a characteristic of all angiosperms?
A) double internal fertilization
B) free-living gametophytes
C) carpels that contain microsporangia
D) ovules that are not contained within ovaries
Which of the following is true during a typical cAMP-type signal transduction event?
A) The second messenger is the last part of the system to be activated.
B) The hormone activates the second messenger by directly binding to it.
C) The second messenger amplifies the hormonal response by attracting more
hormones to the cell being affected.
D) Adenylyl cyclase is activated after the hormone binds to the cell and before
phosphorylation of proteins occurs.
Through studies of insect Malpighian tubules, researchers found that K+ accumulated
on the inner face of the tubule, against its concentration gradient. What can you infer
about the mechanism of transport?
A) Potassium transport is a passive process.
B) Movement of potassium into the lumen of the Malpighian tubules is an
energy-requiring process.
C) Potassium moves out of the tubules at a faster rate than it moves into the lumen of
the tubules.
D) Sodium ions will follow potassium ions.
The developmental precursors to the gonadal tissues of Caenorhabditis elegans
uniquely contain _____.
A) proteins of maternal origin
B) high concentrations of potassium ions
C) T tubules for the propagation of action potentials
D) P granules of mRNA and protein
Lymph hearts are pumping structures that drive lymph through the lymphatic system,
returning it to the circulatory system at the large veins entering the heart. Researchers
examined rate and strength of pumping of lymph hearts in two species of amphibians, a
toad (Bufo marinus) and a frog (Rana catesbiana). During hemorrhage or dehydration,
the volume of blood in the circulatory system falls. (E. A. DeGrauw and S. S. Hillman.
2004. General function and endocrine control of the posterior lymph hearts in Bufo
marinus and Rana catesbiana. Physiological and Biochemical Zoology 77(4):594-600.)
Refer to the paragraph on lymph hearts. What effect would increasing lymph heart
pressure have first?
A) Blood volume would increase.
B) Blood volume would decrease.
C) Hemorrhage would increase.
D) Hemorrhage would decrease.
Damage to the sinoatrial node in humans _____.
A) would block conductance between the bundle branches and the Purkinje fibers
B) would have a negative effect on peripheral resistance
C) would disrupt the rate and timing of cardiac muscle contractions
D) would have a direct effect on blood pressure monitors in the aorta
Some fungal species can kill herbivores while feeding off of sugars from its plant host.
What type of relationship does this fungus have with its host?
A) parasitic
B) mutualistic
C) commensal
D) predatory
Using retroviral vectors for gene therapy might increase the patient’s risk of developing
cancer because they might _____.
A) introduce proteins from the virus
B) not express the genes that were introduced into a patient’s cells
C) not integrate their recombinant DNA into the patient’s genome
D) integrate recombinant DNA into the genome in ways that misregulate the expression
of genes at or near the site of integration
Double fertilization means that_____.
A) flowers must be pollinated twice to yield fruits and seeds
B) one sperm is needed to fertilize the egg, and a second sperm is needed to fertilize the
polar nuclei
C) the egg of the embryo sac is diploid
D) every sperm has two nuclei
The Dunkers are a religious group that moved from Germany to Pennsylvania in the
mid-1700s. They do not marry with members outside their own immediate community.
Today, the Dunkers are genetically unique and differ in gene frequencies, at many loci,
from all other populations including those in their original homeland. Which of the
following likely explains the genetic uniqueness of this population?
A) population bottleneck and Hardy-Weinberg equilibrium
B) heterozygote advantage and stabilizing selection
C) mutation and natural selection
D) founder effect and genetic drift
You want to study divergence of populations, and you need to maximize the rate of
divergence to see results within the period of your grant funding. You will form a new
population by taking some individuals from a source population and isolating them so
the two populations cannot interbreed. What combination of characteristics would
maximize your chance of seeing divergence in this study?
1. Choose a random sample of individuals to form the new population.
2. Choose individuals from one extreme to form the new population.
3. Choose a species to study that produces many offspring.
4. Choose a species to study that produces a few, large offspring.
5. Place the new population in the same type of environment as the source population.
6. Place the new population in a novel environment compared to that of the source
population.
A) 1, 3, and 6
B) 1, 4, and 6
C) 2, 3, and 5
D) 2, 3, and 6
What is the overall charge on the cytoplamsic side of a plant cell plasma membrane?
A) positive
B) negative
C) neutral
How would one explain a testcross involving F1 dihybrid flies in which more
parental-type offspring than recombinant-type offspring are produced?
A) The two genes are closely linked on the same chromosome.
B) The two genes are linked but on different chromosomes.
C) Recombination did not occur in the cell during meiosis.
D) Both of the characters are controlled by more than one gene.
The migratory neural crest cells _____.
A) form most of the central nervous system
B) form the spinal cord in the frog
C) form a variety of neural and non-neural structures
D) form the lining of the lungs and of the digestive tract
A person able to hear only high-frequency sounds would probably have which of the
following structural problems in the ear?
A) The tympanum is damaged because of chronic ear infections.
B) The basilar membrane is stiffened along its entire length.
C) The ear ossicles are abnormally thickened.
D) All of these problems could result in inability to detect low-frequency sound.
Cardiac muscle cells are both _____.
A) striated and interconnected by intercalated disks
B) smooth and under voluntary control
C) striated and under voluntary control
D) smooth and under involuntary control
What is difference between an epidemic and a pandemic?
A) An epidemic is a disease; a pandemic is a treatment.
B) An epidemic is restricted to a local region; a pandemic is global.
C) An epidemic has low mortality; a pandemic has higher mortality.
D) An epidemic is caused by a bacterial infection; a pandemic is caused by a viral
infection.
Which of the following statements correctly describes a portion of the pine life cycle?
A) Female gametophytes use mitosis to produce eggs.
B) Seeds are produced in pollen-producing cones.
C) Pollen grains contain female gametophytes.
D) A pollen tube slowly digests its way through the triploid endosperm.
Which of the following is the strongest evidence that protein structure and function are
correlated?
A) Proteins function best at certain temperatures.
B) Proteins have four distinct levels of structure and many functions.
C) Enzymes tend to be globular in shape.
D) Denatured (unfolded) proteins do not function normally.
When you eat Brussels sprouts, you are eating _____.
A) immature flowers
B) large axillary buds
C) petioles
D) storage leaves
Where would you expect to find tight junctions?
A) in the epithelium of an animal’s stomach
B) between the smooth endoplasmic reticulum and the rough endoplasmic reticulum
C) between plant cells in a woody plant
D) in the plasma membrane of prokaryotes
Use this information to answer the question(s) below.
Suppose an experimenter becomes proficient with a technique that allows her to move
DNA sequences within a prokaryotic genome.
If she moves the repressor gene (lacI), along with its promoter, to a position at some
several thousand base pairs away from its normal position, we would expect the _____.
A) repressor will no longer bind to the operator
B) repressor will no longer bind to the inducer
C) lac operon will be expressed continuously
D) lac operon will function normally
Which of these, if true, would support the claim that the ancestral cnidarians had
bilateral symmetry?
1. Cnidarian larvae possess anterior-posterior, left-right, and dorsal-ventral aspects.
2. Cnidarians have fewer Hox genes than bilaterians.
3. All extant cnidarians, including Nematostella, are diploblastic.
4. β-catenin turns out to be essential for gastrulation in all animals in which it occurs.
5. All cnidarians are acoelomate.
A) 1 and 4
B) 2 and 3
C) 2 and 4
D) 4 and 5
Which of the following has a coefficient of relatedness of 0.25?
A) a father to his daughter
B) an uncle to his nephew
C) a brother to his brother
D) a sister to her brother
Use the following information to answer the question(s) below.
Rose-picker’s disease is caused by the yeast Sporothrix schenkii (S. schenkii). The yeast
grows on the exteriors of rose-bush thorns. If a human gets pricked by such a thorn, the
yeasts can be introduced under the skin. The yeasts then assume a hyphal morphology
and grow along the interiors of lymphatic vessels until they reach a lymph node. This
often results in the accumulation of pus in the lymph node, which subsequently
ulcerates through the skin surface and then drains.
Suppose that S. schenkii had initially been classified as a deuteromycete. Asci were later
discovered in the pus that oozed from an ulcerated lymph node, and the spores therein
germinated, giving rise to S. schenkii yeasts. Which two of these are conclusions make
sense on the basis of this information?
1. S. schenkii produces asexual spores within lymph nodes.
2. S. schenkii should be reclassified.
3. S. schenkii continues to have no known sexual stage.
4. The hyphae growing in lymphatic vessels probably belonged to a different fungal
species.
5. S. schenkii yeasts belonging to two different mating strains were introduced by the
same thorn prick.
A) 1 and 3
B) 1 and 5
C) 2 and 5
D) 4 and 5