If you experimentally increase the concentration of K+ inside a cell while maintaining
other ion concentrations as they were, what would happen to the cell’s membrane
potential?
A) The membrane potential would become more negative.
B) The membrane potential would become less negative.
C) The membrane potential would remain the same.
When a molecule of NAD+ (nicotinamide adenine dinucleotide) gains a hydrogen atom
(not a proton), the molecule becomes _____.
A) dehydrogenated
B) oxidized
C) reduced
D) redoxed
Bipolar disorder differs from schizophrenia in that _____.
A) schizophrenia typically involves hallucinations
B) schizophrenia typically involves manic and depressive states
C) bipolar disorder involves both genes and environment
D) bipolar disorder increases biogenic amines
The pattern of embryonic development in which only the cells lacking yolk
subsequently undergo cleavage is called _____.
A) holoblastic development, which is typical of marsupial mammals
B) meroblastic development, which is typical of humans
C) holoblastic development, which is typical of amphibians
D) meroblastic development, which is typical of birds
Turnover of water in temperate lakes during the spring and fall is made possible by
which of the following?
A) warm, less dense water layered at the top
B) cold, more dense water layered at the bottom
C) a distinct thermocline between less dense, warm water and cold, dense water
D) the changes in the density of water as seasonal temperatures change
Which of the following could be considered an evolutionary advantage of asexual
reproduction in plants?
A) increased success of progeny in a stable environment.
B) increased agricultural productivity in a rapidly changing environment.
C) maintenance and expansion of a large genome.
D) increased ability to adapt to a change in the environment.
In human and many other eukaryotic species’ cells, the nuclear membrane has to
disappear to permit _____.
A) cytokinesis
B) the attachment of microtubules to kinetochores
C) the splitting of the centrosomes
D) the disassembly of the nucleolus
Albinism is an autosomal (not sex-linked) recessive trait. A man and woman are both of
normal pigmentation and have one child out of three who is albino (without melanin
pigmentation). What are the genotypes of the albino’s parents?
A) One parent must be homozygous for the recessive allele; the other parent can be
homozygous dominant, homozygous recessive, or heterozygous.
B) One parent must be heterozygous; the other parent can be homozygous dominant,
homozygous recessive, or heterozygous.
C) Both parents must be heterozygous.
D) One parent must be homozygous dominant; the other parent must be heterozygous.
To reproduce, many plants produce seeds’structures containing embryonic offspring
along with nutrients inside a tough case. These offspring develop after being released
by the parent plant. To which animal reproductive strategy is seed production most
comparable?
A) oviparous reproduction
B) ovoviviparous reproduction
C) viviparous reproduction
The amino acid that operates at most inhibitory synapses in the brain is _____.
A) acetylcholine
B) endorphin
C) nitric oxide
D) gamma-aminobutyric acid (GABA)
An earthquake decimates a ground-squirrel population, killing 98% of the squirrels. The
surviving population happens to have broader stripes, on average, than the initial
population. If broadness of stripes is genetically determined, what effect has the
ground-squirrel population experienced during the earthquake?
A) directional selection
B) disruptive selection
C) a founder event
D) a genetic bottleneck
In E. coli, which enzyme catalyzes the elongation of a new DNA strand in the →
direction?
A) primase
B) DNA ligase
C) DNA polymerase III
D) helicase
What do fungi and arthropods have in common?
A) The haploid state is dominant in both groups.
B) Both groups are predominantly autotrophs that produce their own food.
C) Both groups use chitin for support.
D) Both groups have cell walls.
A lack of which molecule would result in a cell’s inability to “turn off” genes?
A) operon
B) inducer
C) promoter
D) corepressor
Which type of mutant would be most likely to produce a bushier phenotype?
A) auxin overproducer
B) strigolactone overproducer
C) cytokinin underproducer
D) strigolactone underproducer
Which molecule shown above would have a positive charge in a cell?
A) A
B) B
C) C
D) D
Of the following choices, the epithelium with the shortest diffusion distance is _____.
A) simple squamous epithelium
B) simple columnar epithelium
C) pseudostratified ciliated columnar epithelium
D) stratified squamous epithelium
In colorectal cancer, several genes must be mutated for a cell to develop into a cancer
cell. Which of the following kinds of genes would you expect to be mutated?
A) genes coding for enzymes that act in the colon
B) genes involved in control of the cell cycle
C) genes that are especially susceptible to mutation
D) genes of the bacteria, which are abundant in the colon
Which set contains the most closely related terms?
A) megasporangium, megaspore, pollen, ovule
B) microsporangium, microspore, egg, ovary
C) megasporangium, megaspore, egg, ovule
D) microsporangium, microspore, carpel, ovary
Which of the following is NOT true? Both chloroplasts and mitochondria _____.
A) have their own DNA
B) have multiple membranes
C) are part of the endomembrane system
D) are capable of reproducing themselves
Imagine you are resting comfortably on a sofa after dinner. This could be described as a
state with _____.
A) increased activity in the sympathetic, parasympathetic, and enteric nervous systems
B) decreased activity in the sympathetic, parasympathetic, and enteric nervous systems
C) decreased activity in the sympathetic nervous system, and increased activity in the
parasympathetic and enteric nervous systems
D) increased activity in the sympathetic nervous system, and decreased activity in the
parasympathetic and enteric nervous systems
Bacterial cells protect their own DNA from restriction enzymes (endonucleases) by
_____.
A) adding methyl groups to adenines and cytosines
B) using DNA ligase to seal the bacterial DNA into a closed circle
C) adding histones to protect the double-stranded DNA
D) forming ‘sticky ends” of bacterial DNA to prevent the enzyme (endonuclease) from
attaching
About 450 million years ago, the terrestrial landscape on Earth would have _____.
A) looked very similar to that of today, with flowers, grasses, shrubs, and trees
B) been completely bare rock, with little pools that contained bacteria and
cyanobacteria
C) been covered with tall forests in swamps that became today’s coal
D) had non-vascular green plants similar to liverworts forming green mats on rock
Insect hormones and their receptors _____.
A) act independently of each other
B) are a focus in pest control research
C) utilize cell-surface receptors only
D) are active independently of environmental cues
Cells were infected with approximately 1000 copies of either virus A or virus B at the 0
time point. At five-minute intervals, a sample of the virus and cell mixture was
removed. The intact cells were removed from the sample, and the number of viruses per
milliliter of culture was determined.
Using the data in the figure above, how long does it take for virus B to go through one
lytic cycle?
A) 15 minutes
B) 30 minutes
C) 45 minutes
D) 60 minutes
Sequencing eukaryotic genomes is more difficult than sequencing genomes of bacteria
or archaea because of the _____.
A) large size of eukaryotic proteins
B) hard-to-find proteins
C) high proportion of G-C base pairs in eukaryotic DNA
D) large size of eukaryotic genomes and the large amount of eukaryotic repetitive DNA
Sturtevant provided genetic evidence for the existence of four pairs of chromosomes in
Drosophila in which of these ways?
A) There are four major functional classes of genes in Drosophila.
B) Drosophila genes cluster into four distinct groups of linked genes.
C) The overall number of genes in Drosophila is a multiple of four.
D) Drosophila genes have, on average, four different alleles.
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. In both experiments, flies appeared in all
of the open jars and only in the open jars. Which one of the following statements is
correct?
A) The experiment was inconclusive because Redi used only one kind of meat.
B) The experiment was inconclusive because it did not run long enough.
C) The experiment supports the hypothesis that spontaneous generation occurs in
rotting meat.
D) The experiment supports the hypothesis that maggots arise only from eggs laid by
adult flies.
After finding a new medicinal plant, a pharmaceutical company decides to determine if
the plant has genes similar to those of other known medicinal plants. To do this, the
company annotates the genome of the new plant to _____.
A) determine what proteins are produced
B) determine what mRNA transcripts are produced
C) identify genes and determine their functions
D) identify the location of mRNA within the plant cells
A necropsy (postmortem analysis) of a marine sea star that died after it was mistakenly
placed in fresh water would likely show that it died because _____.
A) it was stressed and needed more time to acclimate to the new conditions
B) it was so hypertonic to the fresh water that it could not osmoregulate
C) its contractile vacuoles ruptured
D) its cells dehydrated and lost the ability to metabolize
Which of the following might be an investigation of microclimate?
A) the effect of ambient temperature on the onset of caribou migration
B) the seasonal population fluctuation of nurse sharks in coral reef communities
C) competitive interactions between various species of songbirds during spring
migration
D) the effect of sunlight intensity on species composition in a decaying rat carcass
Measurements of the amount of DNA per nucleus were taken on a large number of cells
from a growing fungus. The measured DNA levels ranged from 3 to 6 picograms per
nucleus. In which stage of the cell cycle did the nucleus contain 6 picograms of DNA?
A) G1
B) S
C) G2
D) M
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.
Figure A
Figure B
Refer to Figure A. Which of the following results would support Simard et al.’s (1997)
hypothesis that fungi can move carbon from one plant to another? [Hypothesis: Sugars
made by one plant during photosynthesis can travel through a mycorrhizal fungus and
be incorporated into the tissues of another plant.]
A) Carbon-14 is found in the birch seedling’s tissues and carbon-13 in the Douglas fir.
B) Carbon-14 is found in the Douglas fir seedling’s tissues and carbon-13 in the birch.
C) Either carbon-13 or carbon-14 is found in the fungal tissues.
D) Either carbon-13 or carbon-14 is found in the cedar seedling’s tissues.
Based on the species-area plot in the figure above, if habitable area on an island were
reduced from 10,000 km2 (square kilometers) to 1000 km2, roughly what percentage of
the species would disappear?
A) 0.3 percent
B) 3 percent
C) 30 percent
D) 60 percent
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.