Semester 1 Review
AP Biology
UCHS
Thalidomide
and L-dopa are
examples of
Pharmaceutical
drugs that occur
as enantiomers, or molecules that
A. have identical three-dimensional shapes.
B. are mirror images of one another.
C. lack an asymmetric carbon.
D. differ in the location of their double
bonds.
E. differ in their electrical charge.
You have isolated
DNA from three
different cell types of
an organism,
determined the relative DNA
content for each type, and plotted the
results.
Which sample might represent an animal cell
in G2 phase of the cell cycle?
A. I
B. II
C. III
D. Either I or II
E. Either II or III
Which of the following pairs of base
sequences could form a short stretch of
a normal double helix of DNA?
A. 5'-purine-pyrimidine-purinepyrimidine-3' with 3'-purinepyrimidine-purine-pyrimidine-5'
B. 5'-A-G-C-T-3' with 5'-T-C-G-A-3'
C. 5'-G-C-G-C-3' with 5'-T-A-T-A-3'
D. 5'-A-T-G-C-3' with 5'-G-C-A-T-3'
A cell has the following molecules and
structures: enzymes, DNA, ribosomes,
plasma membrane, and mitochondria.
It could be a cell from
A. a bacterium.
B. an animal, but not a plant.
C. a plant, but not an animal.
D. a plant or an animal.
E. any kind of organism.
Why isn't the mitochondrion classified
as part of the endomembrane system?
A. It only has two membrane layers.
B. Its structure is not derived from the
ER.
C. It has too many vesicles.
D. It is not involved in protein
synthesis.
E. It is not attached to the outer
nuclear envelope.
Polysaccharides, lipids, and proteins are
similar in that they
A. are synthesized from monomers by the
process of hydrolysis.
B. are synthesized from monomers by
dehydration reactions.
C. are synthesized as a result of peptide
bond formation between monomers.
D. are decomposed into their subunits by
dehydration reactions.
E. all contain nitrogen in their monomer
building blocks.
The DNA of telomeres has been found to be
highly conserved throughout the evolution
of eukaryotes. What does this most
probably reflect?
A. the inactivity of this DNA
B. the low frequency of mutations
occurring in this DNA
C. that new evolution of telomeres
continues
D. that mutations in telomeres are
relatively advantageous
E. that the critical function of telomeres
must be maintained
Which of the following covalently
connects segments of DNA?
A. helicase
B. DNA polymerase III
C. ligase
D. DNA polymerase I
E. primase
The difference between ATP and the nucleoside
triphosphates used during DNA synthesis is that
A. the nucleoside triphosphates have the sugar
deoxyribose; ATP has the sugar ribose.
B. the nucleoside triphosphates have two
phosphate groups; ATP has three phosphate
groups.
C. ATP contains three high-energy bonds; the
nucleoside triphosphates have two.
D. ATP is found only in human cells; the
nucleoside triphosphates are found in all
animal and plant cells.
E. triphosphate monomers are active in the
nucleoside triphosphates, but not in ATP.
Cyanide binds with at least one
molecule involved in producing ATP. If
a cell is exposed to cyanide, most of the
cyanide would be found within the
A. mitochondria.
B. ribosomes.
C. peroxisomes.
D. lysosomes.
E. endoplasmic reticulum.
Why do histones bind tightly to DNA?
A. Histones are positively charged, and
DNA is negatively charged.
B. Histones are negatively charged, and
DNA is positively charged.
C. Both histones and DNA are strongly
hydrophobic.
D. Histones are covalently linked to the
DNA.
E. Histones are highly hydrophobic, and
DNA is hydrophilic.
If an individual has abnormal microtubules, due
to a hereditary condition, in which organs or
tissues would you expect dysfunction?
A. limbs, hearts, areas with a good deal of
contraction
B. microvilli, alveoli, and glomeruli
C. all ducts, such as those from salivary or
sebaceous glands
D. sperm, larynx, and trachea
E. egg cells (ova), uterus, and kidneys
All of the following serve an important role
in determining or maintaining the structure
of plant cells. Which of the following are
distinct from the others in their
composition?
A. microtubules
B. microfilaments
C. plant cell walls
D. intermediate filaments
E. nuclear lamina
Which of the following can be
determined directly from X-ray
diffraction photographs of
crystallized DNA?
A. the diameter of the helix
B. the rate of replication
C. the sequence of nucleotides
D. the bond angles of the subunits
E. the frequency of A vs. T
nucleotides
You have isolated
DNA from three
different cell types of
an organism,
determined the relative DNA
content for each type, and plotted the
results.
Which sample of DNA might be from a
nerve cell arrested in G0 of the cell cycle?
A. I
D. Either I or II
B. II
E. Either II or III
C. III
The leading and the lagging strands differ in that
A. the leading strand is synthesized in the same
direction as the movement of the replication
fork, and the lagging strand is synthesized in the
opposite direction.
B. the leading strand is synthesized by adding
nucleotides to the 3' end of the growing strand,
and the lagging strand is synthesized by adding
nucleotides to the 5' end.
C. the lagging strand is synthesized continuously,
whereas the leading strand is synthesized in
short fragments that are ultimately stitched
together.
D. the leading strand is synthesized at twice the rate
of the lagging strand.
Meiosis II is similar to mitosis in that
A. sister chromatids separate during
anaphase.
B. DNA replicates before the division.
C. the daughter cells are diploid.
D. homologous chromosomes synapse.
E. the chromosome number is
reduced.
DNAase is an enzyme that catalyzes the
hydrolysis of the covalent bonds that join
nucleotides together. What would first happen to
DNA molecules treated with DNAase?
A. The two strands of the double helix would
separate.
B. The phosphodiester bonds between
deoxyribose sugars would be broken.
C. The purines would be separated from the
deoxyribose sugars.
D. The pyrimidines would be separated from the
deoxyribose sugars.
E. All bases would be separated from the
deoxyribose sugars.
Which of the following molecules act as
building blocks (monomers) of
polypeptides?
A. 1, 4, and 6
B. 2, 7, and 8
C. 7, 8, and 13
D. 11, 12, and 13
E. 12, 13, and 15
When a membrane is freeze-fractured, the
bilayer splits down the middle between the
two layers of phospholipids. In an electron
micrograph of a freeze-fractured
membrane, the bumps seen on the fractured
surface of the membrane are
A. peripheral proteins.
B. phospholipids.
C. carbohydrates.
D. integral proteins.
E. cholesterol molecules.
Which of the following is a reasonable explanation
for why unsaturated fatty acids help keep any
membrane more fluid at lower temperatures?
A. The double bonds form kinks in the fatty acid
tails, forcing adjacent lipids to be further apart.
B. Unsaturated fatty acids have a higher cholesterol
content and therefore more cholesterol in
membranes.
C. Unsaturated fatty acids permit more water in the
interior of the membrane.
D. The double bonds block interaction among the
hydrophilic head groups of the lipids.
E. The double bonds result in shorter fatty acid tails
and thinner membranes.
Cell membranes are asymmetrical. Which of the
following is a most likely explanation?
A. The cell membrane forms a border between one
cell and another in tightly packed tissues such as
epithelium.
B. Cell membranes communicate signals from one
organism to another.
C. Cell membrane proteins are determined as the
membrane is being packaged in the ER and
Golgi.
D. The "innerness" and "outerness" of membrane
surfaces are predetermined by genes.
E. Proteins can only span cell membranes if they
are hydrophobic.
The color of Plant A is most likely
A. blue
B. green
C. red
D. violet
E. yellow
In an experiment the rate of photosynthesis in
chloroplasts is measured using a dye called DPIP. Which
of the following statements about the experiment is NOT
correct?
A. DPIP does not change color when it accepts electrons
that would normally be accepted by NADP+.
B. As DPIP accepts electrons, it changes from blue to
clear.
C. An instrument called a spectrophotometer is used to
measure the quantity of light that is absorbed.
D. By varying light intensity it is possible to determine
its effect on photosynthetic rates.
E. By varying light wavelength it is possible to determine
its effect on photosynthetic rates.
The somatic cells derived from a
single-celled zygote divide by which
process?
A. meiosis
B. mitosis
C. replication
D. cytokinesis alone
E. binary fission
You have in your possession a microscope
slide with meiotic cells on it and a light
microscope. What would you look for if
you wanted to identify metaphase I cells
on the slide?
A. A visible nuclear envelope
B. Separated sister chromatids at each
pole of the cell
C. Tetrads lined up at the center of the
cell
D. A synaptonemal complex
E. A cleavage furrow
A mutation results in a cell that no longer
produces a normal protein kinase for the
M phase checkpoint. Which of the
following would likely be the immediate
result of this mutation?
A. The cell would prematurely enter
anaphase.
B. The cell would never leave metaphase.
C. The cell would never enter metaphase.
D. The cell would never enter prophase.
E. The cell would undergo normal
mitosis, but fail to enter the next G1
phase.
Which of the following statements is true regarding
the molecule?
I. It is a saturated fatty acid.
II. A diet rich in this molecule may contribute to
atherosclerosis.
III. Molecules of this type are usually liquid at
room temperature.
A. I only
D. I and II only
B. II only
E. I, II, and III
C. III only
Plant A is most likely to have high amounts of
A. chlorophyll a
B. carotenoids
C. cytochrome c
D. phycobilin
E. porphyrin rings
Glycolysis is thought to be one of the most ancient of
metabolic processes. Which statement supports this
idea?
A. Glycolysis is the most widespread metabolic pathway.
B. Glycolysis neither uses nor needs O2.
C. Glycolysis is found in all eukaryotic cells.
D. The enzymes of glycolysis are found in the cytosol
rather than in a membrane-enclosed organelle.
E. Ancient prokaryotic cells, the most primitive of cells,
made extensive use of glycolysis long before oxygen was
present in Earth's atmosphere.
In liver cells, the inner mitochondrial membranes are
about 5 X the area of the outer mitochondrial
membranes, and about 17 X that of the cell's plasma
membrane. What purpose must this serve?
A. It allows for increased rate of glycolysis.
B. It allows for increased rate of the citric acid cycle.
C. It increases the surface for oxidative phosphoryation.
D. It increases the surface for substrate-level
phosphorylation.
E. It allows the liver cell to have fewer mitochondria.
Recall that the complete oxidation of a mole of glucose releases 686 kcal of energy (ΔG = -686 kcal/mol). The phosphorylation of ADP to form ATP stores approximately 7.3 kca
In mechanism, photophosphorylation is most similar to
A. substrate-level phosphorylation in glycolysis.
B. oxidative phosphorylation in cellular respiration.
C. the Calvin cycle.
D. carbon fixation.
E. reduction of NADP+.
How do the daughter cells at the end of mitosis
and cytokinesis compare with their parent cell
when it was in G1 of the cell cycle?
A. The daughter cells have half the amount of
cytoplasm and half the amount of DNA.
B. The daughter cells have half the number of
chromosomes and half the amount of DNA.
C. The daughter cells have the same number of
chromosomes and half the amount of DNA.
D. The daughter cells have the same number of
chromosomes and the same amount of DNA.
E. The daughter cells have the same number of
chromosomes and twice the amount of DNA.
Water's high specific heat is mainly a
consequence of the
A. small size of the water molecules.
B. high specific heat of oxygen and
hydrogen atoms.
C. absorption and release of heat when
hydrogen bonds break and form.
D. fact that water is a poor heat
conductor.
E. inability of water to dissipate heat
into dry air.
If a cell were unable to produce histone proteins,
which of the following would be a likely effect?
A. There would be an increase in the amount of
"satellite" DNA produced during centrifugation.
B. The cell's DNA couldn't be packed into its
nucleus.
C. Spindle fibers would not form during prophase.
D. Amplification of other genes would compensate
for the lack of histones.
E. Pseudogenes would be transcribed to
compensate for the decreased protein in the cell.
Where does photosynthesis occur in blue-green algae?
A. Thylakoid membrane of chloroplasts
B. Stroma of chloroplasts
C. Inner mitochondrial membrane
D. Cell wall
E. Plasma membrane
C4 plants store CO2 so that stomata stay open for less
time. This is to prevent excess
A. adhesion
B. CO2 intake
C. evaporation
D. O2 release
E. transpiration
Where do CAM plants store the organic acids they make
during the night?
A. The stroma of the chloroplasts.
B. The vascular bundles of the stem.
C. The vacuoles of mesophyll cells.
D. The cytosol of the guard cells.
E. The aquaporins.
Starting with one molecule of glucose, the "net"
products of glycolysis are
A. 2 NAD+, 2 H+, 2 pyruvate, 2 ATP, and 2 H2O .
B. 2 NADH, 2 H+, 2 pyruvate, 2 ATP, and 2 H2O .
C. 2 FADH2, 2 pyruvate, 4 ATP, and 2 H2O .
D. 6 CO2, 6 H2O , 2 ATP, and 2 pyruvate.
E. 6 CO2, 6 H2O , 36 ATP, and 2 citrate.
You have isolated
DNA from three
different cell types of
an organism,
determined the relative DNA
content for each type, and plotted the results.
Which sample might represent a sperm cell?
A. I
D. Either I or II
B. II
E. Either II or III
C. III
1. Formation of four new nuclei, each with half
the chromosomes present in the parental nucleus
2. Alignment of tetrads at the metaphase plate
3. Separation of sister chromatids
4. Separation of the homologues; no uncoupling
of the centromere
5. Synapsis; chromosomes moving to the middle
of the cell in pairs
From the descriptions above, which of the
following is the order that most logically
illustrates a sequence of meiosis?
A. 1, 2, 3, 4, 5 D. 4, 5, 2, 1, 3
B. 5, 4, 2, 1, 3 E. 5, 2, 4, 3, 1
C. 5, 3, 2, 4, 1
16. In plants, ATP is synthesized in the
A. chloroplasts and endoplasmic reticulum
B. chloroplasts and mitochondria
C. cytosol and mitochondria
D. mitochondria and nucleus
E. chloroplasts and cytosol
The action spectrum of plant A should peak at
A. blue
B. green
C. red
D. violet
E. yellow
Synthesis of ATP by the chemiosmotic mechanism
occurs during
A. photosynthesis.
B. respiration.
C. both photosynthesis and respiration. D. neither
photosynthesis nor respiration.
E. photorespiration.
Which cell would be best for
studying lysosomes?
A. muscle cell
B. nerve cell
C. phagocytic white blood cell
D. leaf cell of a plant
E. bacterial cell
A plant has a unique photosynthetic pigment. The leaves
of this plant appear to be reddish yellow. What
wavelengths of visible light are being absorbed by this
pigment?
A. red and yellow
B. blue and violet
C. green and yellow
D. blue, green, and red
E. green, blue, and yellow
A young animal has never had much energy. He is brought to
a veterinarian for help and is sent to the animal hospital for
some tests. There they discover his mitochondria can use
only fatty acids and amino acids for respiration, and his cells
produce more lactate than normal. Of the following, which is
the best explanation of his condition?
A. His mitochondria lack the transport protein that moves
pyruvate across the outer mitochondrial membrane.
B. His cells cannot move NADH from glycolysis into the
mitochondria.
C. His cells contain something that inhibits oxygen use in his
mitochondria.
D. His cells lack the enzyme in glycolysis that forms
pyruvate.
E. His cells have a defective electron transport chain, so
glucose goes to lactate instead of to acetyl CoA.
During oxidative phosphorylation, H2O is formed.
Where does the oxygen for the synthesis of the water
come from?
A. carbon dioxide (CO2)
B. glucose (C6H12O6)
C. molecular oxygen (O2)
D. pyruvate (C3H3O3-)
E. lactate (C3H5O3-)
The gas needed for photosynthesis is
A. CO2 obtained by diffusion through the upper
epidermis
B. CO2 obtained by diffusion regulated by guard cells
C. H2O obtained by osmosis through veins
D. O2 obtained by diffusion through veins
E. O2 obtained by diffusion regulated by guard cells
If this plant is undergoing photorespiration, the Calvin
cycle will release
A. oxygen
B. ATP
C. sucrose
D. carbon dioxide
E. water
If cells in the process of dividing are
subjected to colchicine, a drug that
interferes with the functioning of the
spindle apparatus, at which stage will
mitosis be arrested?
A. anaphase
B. prophase
C. telophase
D. metaphase
E. interphase
Of the following functions, which is most
important for the glycoproteins and glycolipids of
animal cell membranes?
A. facilitated diffusion of molecules down their
concentration gradients
B. active transport of molecules against their
concentration gradients
C. maintaining the integrity of a fluid mosaic
membrane
D. maintaining membrane fluidity at low
temperatures
E. a cell's ability to distinguish one type of
neighboring cell from another
The presence of cholesterol in the plasma membranes of
some animals
A. enables the membrane to stay fluid more easily
when cell temperature drops.
B. enables the animal to remove hydrogen atoms from
saturated phospholipids.
C. enables the animal to add hydrogen atoms to
unsaturated phospholipids.
D. makes the membrane less flexible, allowing it to
sustain greater pressure from within the cell.
E. makes the animal more susceptible to circulatory
disorders.
In order for a protein to be an integral
membrane protein it would have to be
which of the following?
A. hydrophilic
B. hydrophobic
C. amphipathic
D. completely covered with phospholipids
E. exposed on only one surface of the
membrane
When T2 phages infect bacteria and
make more viruses in the presence of
radioactive sulfur, what is the result?
I. The viral DNA will be radioactive.
II. The viral proteins will be
radioactive.
III. The bacterial DNA will be
radioactive.
A. I only
D. I and II only
B. II only
E. I , II, and III
C. III only
The karyotype of one species of primate
has 48 chromosomes. In a particular
female, cell division goes awry and she
produces one of her eggs with an extra
chromosome (25). The most probable
source of this error would be a mistake in
which of the following?
A. Mitosis in her ovary
B. Metaphase I of one meiotic event
C. Telophase II of one meiotic event
D. Telophase I of one meiotic event
E. Either anaphase I or II
The processes of photosynthesis pass from the
A. grana to thylakoid disc
B. stroma to thylakoid disc
C. stroma to grana
D. thylakoid disc to stroma
E. thylakoid disc to grana
During the electron transport chain, an H+ gradient is
established. What happens at the mitochondrial matrix
as a result of this gradient?
A. The pH increases.
B. The proteins disengage from the matrix.
C. Water is formed and used to power the ATP synthase.
D. The rate of glycolysis increases.
E. No event occurs at the mitochondrial matrix.
Which of the following is (are) the reduced form of an
electron carrier?
I. NADH III. FADH2
II. NAD+ IV. FAD
A. I only
B. II only
C. I and III
D. I and IV
E. II and III
The cell walls of bacteria, fungi, and plant cells and the
extracellular matrix of animal cells are all external to the
plasma membrane. Which of the following is a
characteristic of all of these extracellular structures?
A. They must block water and small molecules in order
to regulate the exchange of matter and energy with
their environment.
B. They must permit information transfer between the
cell's cytoplasm and the nucleus.
C. They must provide a rigid structure that maintains
an appropriate ratio of cell surface area to volume.
D. They are constructed of materials that are largely
synthesized in the cytoplasm and then transported
out of the cell.
E. They are composed of a mixture of lipids and
carbohydrates.
The extracellular matrix is thought to
participate in the regulation of animal cell
behavior by communicating information
from the outside to the inside of the cell via
which of the following?
A. gap junctions
B. the nucleus
C. DNA and RNA
D. integrins
E. plasmodesmata
Which statement correctly characterizes bound
ribosomes?
A. Bound ribosomes are enclosed in their own
membrane.
B. Bound and free ribosomes are structurally
different.
C. Bound ribosomes generally synthesize
membrane proteins and secretory proteins.
D. The most common location for bound
ribosomes is the cytoplasmic surface of the
plasma membrane.
Chargaff's analysis of the relative base
composition of DNA was significant because he
was able to show that
A. the relative proportion of each of the four
bases differs within individuals of a species.
B. the human genome is more complex than
that of other species.
C. the amount of A is always equivalent to T,
and C to G.
D. the amount of ribose is always equivalent to
deoxyribose.
E. transformation causes protein to be brought
into the cell.
Why does the DNA double helix have a
uniform diameter?
A. Purines pair with pyrimidines.
B. C nucleotides pair with A
nucleotides.
C. Deoxyribose sugars bind with ribose
sugars.
D. Nucleotides bind with nucleosides.
E. Nucleotides bind with nucleoside
triphosphates.
It became apparent to Watson and
Crick after completion of their model
that the DNA molecule could carry a
vast amount of hereditary information
in which of the following?
A. sequence of bases
B. phosphate-sugar backbones
C. complementary pairing of bases
D. side groups of nitrogenous bases
E. different five-carbon sugars
In an analysis of the nucleotide
composition of DNA, which of
the following will be found?
A. A = C
B. A = G and C = T
C. A + C = G + T
D. G + C = T + A
What is meant by the description
"antiparallel" regarding the strands that make
up DNA?
A. The twisting nature of DNA creates
nonparallel strands.
B. The 5' to 3' direction of one strand runs
counter to the 5' to 3' direction of the other
strand.
C. Base pairings create unequal spacing
between the two DNA strands.
D. One strand is positively charged and the
other is negatively charged.
E. One strand contains only purines and the
other contains only pyrimidines.
Which of the following molecules
contain(s) an aldehyde type of carbonyl
functional group?
A. 1
B. 4
C. 8
D. 10
E. 1 and 4
Why is it necessary to regenerate the reduced forms of
electron carriers during fermentation?
A. The reduced form provides the energy for the
production of ATP.
B. It is required to maintain glycolysis.
C. It is required to allow for the Krebs cycle to continue.
D. It prevents the production of waste products.
E. It allows the process to occur in the presence of
oxygen.
Which of the following happens at the
conclusion of meiosis I?
A. Homologous chromosomes are
separated.
B. The chromosome number per cell is
conserved.
C. Sister chromatids are separated.
D. Four daughter cells are formed.
E. The sperm cells elongate to form a
head and a tail end.
Whether during mitosis or meiosis, sister
chromatids are held together by proteins
referred to as cohesions. Such molecules must
have which of the following properties?
A. They must persist throughout the cell cycle.
B. They must be removed before meiosis can
begin.
C. They must be removed before anaphase can
occur.
D. They must reattach to chromosomes during
G1.
E. They must be intact for nuclear envelope
reformation.
Minutes Spent in Cell Cycle
Phases
The data were obtained
from a study of the length
of time spent in each phase
of the cell cycle by cells of three eukaryotic
organisms designated beta, delta, and gamma. Of
the following, the best conclusion concerning the
difference between the S phases for beta and
gamma is that
A. gamma contains more DNA than beta.
B. beta and gamma contain the same amount of
DNA. C. beta contains more RNA than gamma.
D. gamma contains 48 times more DNA and RNA
than beta.
E. beta is a plant cell and gamma is an animal cell.
Which of the following describe(s)
cyclin-dependent kinase (Cdk)?
I. Cdk is inactive, or "turned off," in
the presence of cyclin.
II. Cdk is present throughout the cell
cycle.
III. Cdk is an enzyme that attaches
phosphate groups to other proteins.
A. I only
D. II and III only
B. II only
E. I, II, and III
C. I and II only
What is the basis for the difference in how the
leading and lagging strands of DNA molecules
are synthesized?
A. The origins of replication occur only at the
5' end.
B. Helicases and single-strand binding proteins
work at the 5' end.
C. DNA polymerase can join new nucleotides
only to the 3' end of a growing strand.
D. DNA ligase works only in the 3'  5'
direction.
E. Polymerase can work on only one strand at
a time.
The spontaneous loss of amino groups from
adenine results in hypoxanthine, an
uncommon base, opposite thymine in DNA.
What combination of molecules could
repair such damage?
A. nuclease, DNA polymerase, DNA ligase
B. telomerase, primase, DNA polymerase
C. telomerase, helicase, single-strand
binding protein
D. DNA ligase, replication fork proteins,
adenylyl cyclase
If a cell has 8 chromosomes at
metaphase of mitosis, how many
chromosomes will it have during
anaphase?
A. 1
B. 2
C. 4
D. 8
E. 16
Chemiosmosis in photosynthesis occurs
A. across the chloroplast membrane
B. across the plasma membrane
C. across the thylakoid membrane
D. within the grana only
E. within the stroma only
What would be an unexpected consequence of changing
one amino acid in a protein consisting of 325 amino
acids?
I. The primary structure of the protein would be
changed.
II. The tertiary structure of the protein might be
changed.
III. The biological activity or function of the protein
might be altered.
A. I only
B. II only
C. I and III only
D. II and III only
E. I, II, and III
If mammalian cells receive a go-ahead
signal at the G1 checkpoint, they will
A. move directly into telophase.
B. complete the cycle and divide.
C. exit the cycle and switch to a
nondividing state.
D. show a drop in MPF concentration.
E. complete cytokinesis and form new
cell walls.
Through a microscope, you can see a cell
plate beginning to develop across the
middle of a cell and nuclei re-forming on
either side of the cell plate. This cell is
most likely
A. an animal cell in the process of
cytokinesis.
B. a plant cell in the process of
cytokinesis.
C. an animal cell in the S phase of the cell
cycle.
D. a bacterial cell dividing.
A given organism has 46 chromosomes
in its karyotype. We can therefore
conclude which of the following?
A. It must be human.
B. It must be a primate.
C. It must be an animal.
D. It must be sexually reproducing.
E. Its gametes must have 23
chromosomes.
Chromatids are separated from each
other.
A. The statement is true for mitosis only.
B. The statement is true for meiosis I
only.
C. The statement is true for meiosis II
only.
D. The statement is true for mitosis and
meiosis I.
E. The statement is true for mitosis and
meiosis II.
A tetrad includes which of the
following sets of DNA strands?
A. Two single-stranded chromosomes
that have synapsed
B. Two sets of sister chromatids that
have synapsed
C. Four sets of sister chromatids
D. Four sets of unique chromosomes
E. Eight sets of sister chromatids
Caffeine is an inhibitor of
phosphodiesterase. Therefore, the cells
of a person who has recently
consumed coffee would have increased
levels of
A. phosphorylated proteins.
B. GTP.
C. cAMP.
D. adenylyl cyclase.
E. activated G proteins.
In general, a signal transmitted via
phosphorylation of a series of proteins
A. brings a conformational change to
each protein.
B. requires binding of a hormone to a
cytosol receptor.
C. cannot occur in yeasts because they
lack protein phosphatases.
D. requires phosphorylase activity.
E. allows target cells to change their
shape and therefore their activity.
The termination phase of cell signaling
requires which of the following?
A. removal of the receptor
B. activation of a different set of relay
molecules
C. converting ATP to cAMP
D. reversing the binding of signal
molecule to the receptor
E. apoptosis
Lipid-soluble signal molecules, such as
testosterone, cross the membranes of all cells
but affect only target cells because
A. only target cells retain the appropriate
DNA segments.
B. intracellular receptors are present only in
target cells.
C. most cells lack the Y chromosome
required.
D. only target cells possess the cytosolic
enzymes that transduce the testosterone.
E. only in target cells is testosterone able to
initiate the phosphorylation cascade
leading to activated transcription factor.
Consider this pathway: epinephrine 
G protein-coupled receptor  G
protein  adenylyl cyclase  cAMP.
Identify the second messenger.
A. cAMP
B. G protein
C. GTP
D. adenylyl cyclase
E. G protein-coupled receptor
Suppose you are provided with an actively dividing
culture of E. coli bacteria to which radioactive
thymine has been added. What would happen if a
cell replicates once in the presence of this
radioactive base?
A. One of the daughter cells, but not the other,
would have radioactive DNA.
B. Neither of the two daughter cells would be
radioactive.
C. All four bases of the DNA would be radioactive.
D. Radioactive thymine would pair with
nonradioactive guanine.
E. DNA in both daughter cells would be
radioactive.