AP Biology Midterm Review – Previous Test Questions
AP Biology - Chap 3-6 Assessment
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____
1) In a plant cell, DNA may be found ____.
A) in the nucleus, mitochondria, chloroplasts, and peroxisomes
B) only in the nucleus and chloroplasts
C) only in the nucleus
D) in the nucleus, mitochondria, and chloroplasts
____
2) Which of the following is present in a prokaryotic cell?
A) ribosome
B) mitochondrion
C) chloroplast
D) ER
____
3) Phospholipids and triglycerides both ____.
A) have three fatty acids
B) have a glycerol backbone
C) have a phosphate
D) contain serine or some other organic compound
____
4) Which of the following is the strongest evidence that protein structure and function are
correlated?
A) Enzymes tend to be globular in shape.
B) Proteins function best at certain temperatures.
C) Proteins have four distinct levels of structure and many functions.
D) Denatured (unfolded) proteins do not function normally.
____
5) A solution with a pH of 5 has how many more protons in it than a solution with a pH of
7?
A) 10 times
B) 100 times
C) 5 times
D) 1000 times
____
6) Suppose a young boy is always tired and fatigued, suffering from a metabolic disease.
Which of the following organelles is most likely involved in this disease?
A) mitochondria
B) ribosomes
C) Golgi apparatus
D) lysosomes
____
7) If one strand of a DNA molecule has the sequence of bases 5'ATTGCA3', the other
complementary strand would have the sequence ____.
A) 5'UGCAAU3'
B) 3'UAACGU5'
C) 5'TAACGT3'
D) 5'TGCAAT3'
____
8) Where are proteins produced other than on ribosomes free in the cytosol or ribosomes
attached to the ER?
A) in the extracellular matrix
B) in the Golgi apparatus
C) in the nucleolus
D) in mitochondria
____
9) One of the buffers that contribute to pH stability in human blood is carbonic acid
(H2CO3). Carbonic acid is a weak acid that, when placed in an aqueous solution,
dissociates into a bicarbonate ion (HCO3-) and a hydrogen ion (H+), as noted below.
If the pH of blood drops, one would expect ____.
A) the HCO3- to act as an acid and remove excess H+ by the formation of H2CO3
B) the concentration of bicarbonate ions (HCO3-) to increase
C) a decrease in the concentration of H2CO3 and an increase in the concentration of
HCO3D) the HCO3- to act as a base and remove excess H+ by the formation of H2CO3
____
10) Spherocytosis is a human blood disorder associated with a defective cytoskeletal protein
in the red blood cells (RBCs). What do you suspect is the consequence of such a defect?
A) adherence of RBCs to blood vessel walls, causing plaque formation
B) abnormally shaped RBCs
C) an insufficient supply of oxygen-transporting proteins in the RBCs
D) an insufficient supply of ATP in the RBCs
____
11) 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
____
12) What is the term used for a protein molecule that assists in the proper folding of other
proteins?
A) renaturing protein
B) tertiary protein
C) chaperonin
D) denaturing protein
____
13) Stanley Miller's 1953 experiments supported the hypothesis that ____.
A) life on Earth arose from simple inorganic molecules
B) the conditions on early Earth were conducive to the origin of life
C) life on Earth arose from simple organic molecules, with energy from lightning and
volcanoes
D) organic molecules can be synthesized abiotically under conditions that may have
existed on early Earth
____
14) What is the most likely pathway taken by a newly synthesized protein that will be
secreted by a cell?
A) Golgi  ER  lysosome
B) ER  lysosomes  vesicles that fuse with plasma membrane
C) ER  Golgi  vesicles that fuse with plasma membrane
D) ER  Golgi  nucleus
____
15) Which one of the following is NOT a component of each monomer used to make
proteins?
A) a side chain, R
B) a carboxyl group, COOH
C) an amino functional group, NH2
D) a phosphorus atom, P
____
16) Which of the following takes place as an ice cube cools a drink?
A) Kinetic energy in the liquid water decreases.
B) A calorie of heat energy is transferred from the ice to the water of the drink.
C) The specific heat of the water in the drink decreases.
D) Molecular collisions in the drink increase.
____
17) The R-group, or side chain, of the amino acid serine is -CH2-OH. The R-group, or side
chain, of the amino acid leucine is -CH2-CH-(CH3)2. Where would you expect to find
these amino acids in a globular protein in aqueous solution?
A) Serine would be in the interior, and leucine would be on the exterior of the
globular protein.
B) Serine and leucine would both be on the exterior of the globular protein.
C) Serine and leucine would both be in the interior of the globular protein.
D) Leucine would be in the interior, and serine would be on the exterior of the
globular protein.
____
18) Suppose 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) nearly any eukaryotic organism
D) a plant but not an animal
____
19) Humans can digest starch but not cellulose because ____.
A) starch monomers are joined by covalent bonds and cellulose monomers are joined
by ionic bonds
B) the monomer of starch is glucose, while the monomer of cellulose is galactose
C) the monomer of starch is fructose, while the monomer of cellulose is glucose
D) humans have enzymes that can hydrolyze the -glycosidic linkages of starch but
not the -glycosidic linkages of cellulose
____
20) Which of the following molecules is polar?
C3H7OH
C2H5COOH
A) C2H5COOH is polar, but C3H7OH is not polar.
B) C3H7OH is not polar, but C3H7OH is polar.
C) C3H7OH and C2H5COOH are both polar molecules.
D) Neither C2H5COOH or C3H7OH is polar.
AP Test Style
1)
The water molecules in the diagram are attracted to the cell walls of water-conducting
cells by adhesion due to hydrogen bonds. What conclusion is supported by this
information?
A) Cell walls of plants are composed of non-polar molecules.
B) Cell walls of plants contain molecular grooves that physically hold the water
molecule.
C) Cell walls of plants contain oxygen and/or nitrogen and are therefore polar.
D) Cell walls of plants are formed from the products of photosynthesis.
Essay
1) No cell can function without the basic requirements. Certain organelles are required for
basic life functions. It is known that cell organelles are associated closely to many
carbon macromolecules.
A) List the 4 molecules/organelles that ALL living organisms must have include as part
of their cells to survive.
B) Choose two of those molecules/organelles and explain how they are tied directly to at
least one of the four carbon compounds.
AP Bio - Chap 7 and 11 quiz
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____
1) Why is apoptosis potentially threatening to the healthy "neighbors" of a dying cell?
A) Cell death would usually spread from one cell to the next via paracrine signals.
B) Lysosomal enzymes exiting the dying cell would damage surrounding cells.
C) Bits of membrane from the dying cell could merge with neighboring cells and
bring in foreign receptors.
D) Neighboring cells would activate immunological responses.
____
2) Lipid-soluble signaling 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) only target cells possess the cytosolic enzymes that transduce the testosterone
D) only in target cells is testosterone able to initiate the phosphorylation cascade
leading to activated transcription factor
____
3) Which of the following most accurately describes selective permeability?
A) An input of energy is required for transport.
B) Lipid-soluble molecules pass through a membrane.
C) There must be a concentration gradient for molecules to pass through a membrane.
D) Only certain molecules can cross a cell membrane.
____
4) Phosphorylation cascades involving a series of protein kinases are useful for cellular
signal transduction because they ____.
A) are species specific
B) always lead to the same cellular response
C) amplify the original signal many times
D) counter the harmful effects of phosphatases
____
5) At puberty, an adolescent female body changes in both structure and function of several
organ systems, primarily under the influence of changing concentrations of estrogens and
other steroid hormones. How can one hormone, such as estrogen, mediate so many
effects?
A) Estrogen is produced in very large concentration by nearly every tissue of the
body.
B) Each cell responds in the same way when steroids bind to the cell surface.
C) Estrogen is kept away from the surface of any cells not able to bind it at the
surface.
D) Estrogen binds to specific receptors inside many kinds of cells, each with different
responses.
____
6) In receptor-mediated endocytosis, receptor molecules initially project to the outside of the
cell. Where do they end up after endocytosis?
A) on the outside of vesicles
B) on the inside surface of the cell membrane
C) on the inside surface of the vesicle
D) on the outer surface of the nucleus
____
7) Protein kinase is an enzyme that ____.
A) functions as a second messenger molecule
B) serves as a receptor for various signal molecules
C) activates or inactivates other proteins by adding a phosphate group to them
D) produces second messenger molecules
____
8) Consider this pathway: epinephrine  G protein-coupled receptor  G protein 
adenylyl cyclase  cAMP. The second messenger in this pathway is ____.
A) cAMP
B) G protein
C) adenylyl cyclase
D) G protein-coupled receptor
____
9) What will happen to a red blood cell (RBC), which has an internal ion concentration of
about 0.9 percent, if it is placed into a beaker of pure water?
A) The cell would shrink because the water in the beaker is hypotonic relative to the
cytoplasm of the RBC.
B) The cell would shrink because the water in the beaker is hypertonic relative to the
cytoplasm of the RBC.
C) The cell would swell because the water in the beaker is hypotonic relative to the
cytoplasm of the RBC.
D) The cell will remain the same size because the solution outside the cell is isotonic.
____
10) When a neuron responds to a particular neurotransmitter by opening gated ion channels,
the neurotransmitter is serving as which part of the signal pathway?
A) relay molecule
B) transducer
C) signal molecule
D) response molecule
____
11) One of the major categories of receptors in the plasma membrane reacts by forming
dimers, adding phosphate groups, and then activating relay proteins. Which type does
this?
A) G protein-coupled receptors
B) ligand-gated ion channels
C) steroid receptors
D) receptor tyrosine kinases
____
12) Which of the following is a type of local signaling in which a cell secretes a signal
molecule that affects neighboring cells?
A) hormonal signaling
B) autocrine signaling
C) paracrine signaling
D) synaptic signaling
____
13) The difference between pinocytosis and receptor-mediated endocytosis is that ____.
A) pinocytosis brings only water molecules into the cell, but receptor-mediated
endocytosis brings in other molecules as well.
B) pinocytosis increases the surface area of the plasma membrane, whereas receptormediated endocytosis decreases the plasma membrane surface area.
C) pinocytosis is nonselective in the molecules it brings into the cell, whereas
receptor-mediated endocytosis offers more selectivity.
D) pinocytosis can concentrate substances from the extracellular fluid, but receptormediated endocytosis cannot.
____
14) A bacterium engulfed by a white blood cell through phagocytosis will be digested by
enzymes contained in ____.
A) lysosomes
B) Golgi vesicles
C) vacuoles
D) secretory vesicles
____
15) Which of the following processes includes all others?
A) osmosis
B) facilitated diffusion
C) passive transport
D) transport of an ion down its electrochemical gradient
____
16) When a plant cell, such as one from a rose stem, is submerged in a very hypotonic
solution, what is likely to occur?
A) The cell will burst.
B) Plasmolysis will shrink the interior.
C) The cell will become flaccid.
D) The cell will become turgid.
____
17) Which of the following would be inhibited by a drug that specifically blocks the addition
of phosphate groups to proteins?
A) G protein-coupled receptor binding
B) ligand-gated ion channel signaling
C) adenylyl cyclase activity
D) receptor tyrosine kinase activity
____
18) Which of the following membrane activities requires energy from ATP?
A) facilitated diffusion of chloride ions across the membrane through a chloride
channel
B) movement of Na+ ions from a lower concentration in a mammalian cell to a higher
concentration in the extracellular fluid
C) movement of glucose molecules into a bacterial cell from a medium containing a
higher concentration of glucose than inside the cell
D) movement of carbon dioxide out of a paramecium
Five dialysis bags constructed of membrane, which is permeable to water and
impermeable to sucrose, were filled with various concentrations of sucrose and then
placed in separate beakers containing an initial concentration of 0.6 M sucrose solution.
At 10-minute intervals, the bags were massed (weighed) and the percent change in mass
of each bag was graphed.
____
19) Which line in the graph represents the bag that contained a solution isotonic to the 0.6 M
solution at the beginning of the experiment?
A) A
B) B
C) C
D) D
____
20) In general, a signal transmitted via phosphorylation of a series of proteins ____.
A) results in a conformational change to each protein
B) requires binding of a hormone to an intracellular receptor
C) activates a transcription event
D) generates ATP in the process of signal transduction
AP Biology - Chap 8-10 Energy, Photosynthesis and Respiration
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____
1)
Rate of an enzyme-catalyzed reaction as a function of varying reactant
concentration, with the concentration of enzyme constant.
In the figure, why does the reaction rate plateau at higher reactant concentrations?
A) The rate of the reverse reaction increases with reactant concentration.
B) Most enzyme molecules are occupied by substrate at high reactant concentrations.
C) Feedback inhibition by product occurs at high reactant concentrations.
D) The reaction nears equilibrium at high reactant concentrations.
____
2) You have a friend who lost 7 kg (about 15 pounds) of fat on a regimen of strict diet and
exercise. How did the fat leave his body?
A) It was converted to heat and then released.
B) It was released as CO2 and H2O.
C) It was converted to ATP, which weighs much less than fat.
D) It was converted to urine and eliminated from the body.
____
3) Which of the following statements best describes the relationship between photosynthesis
and respiration?
A) Respiration runs the biochemical pathways of photosynthesis in reverse.
B) Photosynthesis occurs only in plants; respiration occurs only in animals.
C) Photosynthesis stores energy in complex organic molecules; respiration releases
energy from complex organic molecules
D) Photosynthesis is catabolic; respiration is anabolic.
____
4) Which term most precisely describes the cellular process of breaking down large
molecules into smaller ones?
A) catabolism (catabolic pathways)
B) anabolism (anabolic pathways)
C) dehydration
D) metabolism
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.
____
5) 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) competitive inhibition
B) denaturation
C) vaccination
D) allosteric regulation
____
6) During a laboratory experiment, you discover that an enzyme-catalyzed reaction has a
G of -20 kcal/mol. If you double the amount of enzyme in the reaction, what will be the
G for the new reaction?
A) -20 kcal/mol
B) +20 kcal/mol
C) -40 kcal/mol
D) 0 kcal/mol
____
7) Carbohydrates and fats are considered high-energy foods because they ____.
A) have a lot of electrons associated with hydrogen.
B) have no nitrogen in their makeup.
C) have a lot of oxygen atoms.
D) are easily reduced.
____
8) Substrate-level phosphorylation occurs ____.
A) in both glycolysis and the citric acid cycle
B) in the citric acid cycle
C) in glycolysis
D) during oxidative phosphorylation
____
9) The process of photosynthesis probably originated ____.
A) in fungi
B) three separate times during evolution
C) in prokaryotes
D) in plants
____
10) The primary role of oxygen in cellular respiration is to ____.
A) act as an acceptor for electrons and hydrogen, forming water
B) combine with carbon, forming CO2
C) yield energy in the form of ATP as it is passed down the respiratory chain
D) combine with lactate, forming pyruvate
____
11) Why is ATP an important molecule in metabolism?
A) It provides energy coupling between exergonic and endergonic reactions.
B) Its terminal phosphate group contains a strong covalent bond that, when
hydrolyzed, releases free energy.
C) Its terminal phosphate bond has higher energy than the other two phosphate bonds.
D) Its hydrolysis provides an input of free energy for exergonic reactions.
____
12) Which kind of metabolic poison would most directly interfere with glycolysis?
A) an agent that closely mimics the structure of glucose but is not metabolized
B) an agent that binds to pyruvate and inactivates it
C) an agent that reacts with oxygen and depletes its concentration in the cell
D) an agent that reacts with NADH and oxidizes it to NAD+
____
13) A young dog has never had much energy. He is brought to a veterinarian for help and she
decides to conduct several diagnostic tests. She discovers that the dog's 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 the dog's condition?
A) His mitochondria lack the transport protein that moves pyruvate across the outer
mitochondrial membrane.
B) His cells lack the enzyme in glycolysis that forms pyruvate.
C) His cells have a defective electron transport chain, so glucose goes to lactate
instead of to acetyl CoA.
D) His cells cannot move NADH from glycolysis into the mitochondria.
____
14) Which of the following involves a decrease in entropy?
A) depolymerization reactions
B) condensation reactions
C) hydrolysis reactions
D) reactions that separate monomers
____
15) Living organisms increase in complexity as they grow, resulting in a decrease in the
entropy of an organism. How does this relate to the second law of thermodynamics?
A) Living organisms do not obey the second law of thermodynamics, which states that
entropy must increase with time.
B) Living organisms are able to transform energy into entropy.
C) As a consequence of growing, organisms cause a greater increase in entropy in
their environment than the decrease in entropy associated with their growth.
D) Life obeys the second law of thermodynamics because the decrease in entropy as
the organism grows is exactly balanced by an increase in the entropy of the
universe.
____
16) Some photosynthetic organisms contain chloroplasts that lack photosystem II, yet are
able to survive. The best way to detect the lack of photosystem II in these organisms
would be to ____.
A) do experiments to generate an action spectrum
B) test for liberation of O2 in the light
C) determine if they have thylakoids in the chloroplasts
D) test for CO2 fixation in the dark
____
17) The oxygen consumed during cellular respiration is involved directly in which process or
event?
A) accepting electrons at the end of the electron transport chain
B) glycolysis
C) the oxidation of pyruvate to acetyl CoA
D) the citric acid cycle
Use the following figure to answer the questions below.
____
18) What wavelength of light in the figure is most effective in driving photosynthesis?
A) 730 mm
B) 420 mm
C) 625 mm
D) 575 mm
____
19) As electrons are passed through the system of electron carriers associated with
photosystem II, they lose energy. What happens to this energy?
A) It is lost as heat.
B) It is used to establish and maintain a proton gradient.
C) It is used to phosphorylate NAD+ to NADPH, the molecule that accepts electrons
from photosystem I.
D) It excites electrons of the reaction center of photosystem I.
____
20) When oxygen is released as a result of photosynthesis, it is a direct by-product of ____.
A) the electron transfer system of photosystem II
B) chemiosmosis
C) splitting water molecules
D) the electron transfer system of photosystem I
____
21) Most of the CO2 from the catabolism of glucose is released during ____.
A) glycolysis
B) electron transport
C) the citric acid cycle
D) chemiosmosis
____
22) A chemical reaction that has a positive G is best described as ____.
A) endergonic
B) spontaneous
C) exergonic
D) enthalpic
____
23) In its mechanism, photophosphorylation is most similar to ____.
A) the Calvin cycle
B) substrate-level phosphorylation in glycolysis
C) reduction of NADP+
D) oxidative phosphorylation in cellular respiration
____
24) Which of the following occurs in the cytosol of a eukaryotic cell?
A) oxidation of pyruvate to acetyl CoA
B) fermentation and chemiosmosis
C) citric acid cycle
D) glycolysis and fermentation
____
25) Assume a thylakoid is somehow punctured so that the interior of the thylakoid is no
longer separated from the stroma. This damage will most directly affect the ____.
A) synthesis of ATP
B) flow of electrons from photosystem II to photosystem I
C) splitting of water
D) reduction of NADP+
The following questions are based on the reaction A + B  C + D shown in the
accompanying figure.
____
26) Which of the following in the figure would be the same in either an enzyme-catalyzed or
a noncatalyzed reaction?
A) A
B) B
C) C
D) D
____
27) In photosynthetic cells, synthesis of ATP by the chemiosmotic mechanism occurs during
____.
A) neither photosynthesis nor respiration
B) photosynthesis only
C) photosynthesis and respiration
D) respiration only
____
28) Energy released by the electron transport chain is used to pump H+ into which location in
eukaryotic cells?
A) mitochondrial inner membrane
B) mitochondrial intermembrane space
C) mitochondrial matrix
D) mitochondrial outer membrane
____
29) During aerobic respiration, electrons travel downhill in which sequence?
A) glucose  ATP  electron transport chain  NADH
B) glucose  pyruvate  ATP  oxygen
C) food  glycolysis  citric acid cycle  NADH  ATP
D) glucose  NADH  electron transport chain  oxygen
____
30) The chemiosmotic hypothesis is an important concept in our understanding of cellular
metabolism in general because it explains ____.
A) how electron transport can fuel substrate-level phosphorylation
B) the reduction of oxygen to water in the final steps of oxidative metabolism
C) the sequence of the electron transport chain molecules
D) how ATP is synthesized by a proton motive force
____
31) Plants photosynthesize ____.
A) only in the light but respire in light and dark
B) only in the dark but respire only in the light
C) only in the light but respire only in the dark
D) and respire only in the light
AP Test Style
1)
ATP synthase is a key enzyme of mitochondrial energy conversion. Mitochondrial ATP
synthase deficiency is due to a mutation in a gene important for the formation of a
subunit in the ATP synthase complex.
Scientists could use cells with this gene mutation to investigate which of the following
questions?
A) What effect does the mutation have on the movement of electrons between the
electron carriers of the electron transport chain?
B) What effect does the mutation have on the number of protons pumped into the
intermembrane space of the mitochondria?
C) What effect does the mutation have on the amount of ATP synthesized during
cellular respiration?
D) What effect does the mutation have on the number of water molecules formed at
the end of the electron transport chain?
2) In a biological reaction, succinate dehydrogenase catalyzes the conversion of succinate to
fumarate. The reaction is inhibited by malonic acid, a substance that resembles succinate
but cannot be acted upon by succinate dehydrogenase. Increasing the amount of succinate
molecules to those of malonic acid reduces the inhibitory effect if malonic acid. Select
the correct identification of the molecules described in the reaction.
A) Succinate dehydrogenase is the enzyme, and fumarate is the substrate in the
reaction.
B) Succinate dehydrogenase is the enzyme, and malonic acid is the substrate in the
reaction.
C) Succinate is the substrate, and fumarate is the product in the reaction.
D) Fumarate is the product, and malonic acid is a noncompetitive inhibitor in the
reaction.
Chap 12 and 16
Multiple Choice
Identify the choice that best completes the statement or answers the question.
Use the data in the accompanying table to answer the following questions.
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.
Minutes Spent in Cell Cycle Phases
____
1) The best conclusion concerning delta is that the cells ____.
A) are in the G0 phase.
B) contain no DNA.
C) contain no RNA.
D) divide in the G1 phase.
____
2) The M-phase checkpoint ensures that all chromosomes are attached to the mitotic
spindle. If this does not happen, cells would most likely be arrested in ____.
A) telophase
B) prophase
C) prometaphase
D) metaphase
____
3) Cyclin-dependent kinase (Cdk) is ____.
A) the enzyme that catalyzes the attachment of chromosomes to microtubules
B) present only during the S phase of the cell cycle
C) an enzyme that attaches phosphate groups to other proteins
D) inactive, or "turned off," in the presence of cyclin
____
4) Once a cell completes mitosis, molecular division triggers must be turned off. What
happens to MPF during mitosis?
A) It is exported from the cell.
B) It is completely degraded.
C) The cyclin component of MPF is degraded.
D) The Cdk component of MPF is degraded and exported from the cell.
____
5) Neurons and some other specialized cells divide infrequently because they ____.
A) can no longer bind Cdk to cyclin
B) have entered into G0
C) show a drop in MPF concentration
D) no longer have active nuclei
____
6) DNA contains the template needed to copy itself, but it has no catalytic activity in cells.
What catalyzes the formation of phosphodiester bonds between adjacent nucleotides in
the DNA polymer being formed?
A) ribozymes
B) DNA polymerase
C) deoxyribonucleotide triphosphates
D) ATP
____
7) Which of the following help(s) to hold the DNA strands apart while they are being
replicated?
A) ligase
B) DNA polymerase
C) single-strand DNA binding proteins
D) primase
____
8) Telomere shortening puts a limit on the number of times a cell can divide. Research has
shown that telomerase can extend the life span of cultured human cells. How might
adding telomerase affect cellular aging?
A) Telomerase would have no effect on cellular aging.
B) Telomerase eliminates telomere shortening and retards aging.
C) Telomerase shortens telomeres, which delays cellular aging.
D) Telomerase will speed up the rate of cell proliferation.
____
9) In a healthy cell, the rate of DNA repair is equal to the rate of DNA mutation. When the
rate of repair lags behind the rate of mutation, what is a possible fate of the cell?
A) The cell will become embryonic.
B) DNA synthesis will continue by a new mechanism.
C) The cell can be transformed to a cancerous cell.
D) RNA may be used instead of DNA as inheritance material.
____
10) Which of the following is a protein maintained at steady levels throughout the cell cycle
that requires cyclin to become catalytically active?
A) cyclin
B) MPF
C) Cdk
D) PDGF
____
11) Which of the following does NOT occur during mitosis?
A) replication of the DNA
B) condensation of the chromosomes
C) spindle formation
D) separation of the spindle poles
Use the following information to answer the questions below.
The unlettered circle at the top of the figure shows a diploid nucleus with four
chromosomes that have not yet replicated. There are two pairs of homologous
chromosomes, one long and the other short. One haploid set is black, and the other is
gray. The circles labeled A to E show various combinations of these chromosomes.
____
12) What is the correct chromosomal condition for one daughter nucleus at telophase of
mitosis?
A) E
B) C
C) D
D) B
____
13) If a cell were unable to produce histone proteins, which of the following would be a
likely effect?
A) The cell's DNA couldn't be packed into its nucleus.
B) Spindle fibers would not form during prophase.
C) There would be an increase in the amount of "satellite" DNA produced during
centrifugation.
D) Amplification of other genes would compensate for the lack of histones.
____
14)
Refer to the figure above. What bases will be added to the primer as DNA replication
proceeds? The bases should appear in the new strand in the order that they will be added
starting at the 3' end of the primer.
A) C, A, G, C, A, G, A
B) G, T, C, G, T, C, T
C) T, C, T, G, C, T, G
D) A, G, A, C, G, A, C
____
15) What is meant by the description "antiparallel" regarding the strands that make up DNA?
A) The 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other
strand.
B) One strand contains only purines and the other contains only pyrimidines.
C) Base pairings create unequal spacing between the two DNA strands.
D) The twisting nature of DNA creates nonparallel strands.
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16) DNA is synthesized through a process known as ____.
A) conservative replication
B) transcription
C) translation
D) semiconservative replication
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17) Movement of the chromosomes during anaphase would be most affected by a drug that
prevents ____.
A) shortening of microtubules
B) formation of a cleavage furrow
C) elongation of microtubules
D) nuclear envelope breakdown
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18) A new DNA strand elongates only in the 5' to 3' direction because ____.
A) DNA polymerase can add nucleotides only to the free 3' end
B) the polarity of the DNA molecule prevents addition of nucleotides at the 3' end
C) DNA polymerase begins adding nucleotides at the 5' end of the template
D) replication must progress toward the replication fork
The following questions are based on the accompanying figure.
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19) In the figure above, G1 is represented by which numbered part(s) of the cycle?
A) II or IV
B) III only
C) I or V
D) V only
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20) You briefly expose bacteria undergoing DNA replication to radioactively labeled
nucleotides. When you centrifuge the DNA isolated from the bacteria, the DNA separates
into two classes. One class of labeled DNA includes very large molecules (thousands or
even millions of nucleotides long), and the other includes short stretches of DNA (several
hundred to a few thousand nucleotides in length). These two classes of DNA probably
represent ____.
A) leading strands and Okazaki fragments
B) Okazaki fragments and RNA primers
C) leading strands and RNA primers
D) lagging strands and Okazaki fragments