Campbell’s Biology, 9e (Reece et al.)
Chapter 12 The Cell Cycle
In this chapter, 24 questions are new, and 12 have been altered to incorporate new material from the
textbook. As in the other chapters, any questions that depend on figures or introductory scenarios have
been placed at the end of the chapter rather than in concept sequence.
Multiple-Choice Questions
1) The centromere is a region in which
A) chromatids remain attached to one another until anaphase.
B) metaphase chromosomes become aligned at the metaphase plate.
C) chromosomes are grouped during telophase.
D) the nucleus is located prior to mitosis.
E) new spindle microtubules form at either end.
2) Starting with a fertilized egg (zygote), a series of five cell divisions would produce an early embryo
with how many cells?
A) 4
B) 8
C) 16
D) 32
E) 64
3) If there are 20 chromatids in a cell, how many centromeres are there?
A) 10
B) 20
C) 30
D) 40
E) 80
4) For a newly evolving protist, what would be the advantage of using eukaryote-like cell division rather
than binary fission?
A) Binary fission would not allow for the formation of new organisms.
B) Cell division would allow for the orderly and efficient segregation of multiple linear chromosomes.
C) Cell division would be faster than binary fission.
D) Cell division allows for lower rates of error per chromosome replication.
E) Binary fission would not allow the organism to have complex cells.
5) Suppose a biologist can separate one of a dozen pieces of chromatin from a eukaryotic (animal)
nucleus. It might consist of which of the following?
A) one-twelfth of the genes of the organism
B) two chromosomes, each with six chromatids
C) a single circular piece of DNA
D) two long strands of DNA plus proteins
E) two chromatids attached together at a centromere
6) At which phase are centrioles beginning to move apart in animal cells?
A) telophase
B) anaphase
C) prometaphase
D) metaphase
E) prophase
7) If cells in the process of dividing are subjected to colchicine, a drug that interferes with the formation
of the spindle apparatus, at which stage will mitosis be arrested?
A) anaphase
B) prophase
C) telophase
D) metaphase
E) interphase
8) If there are 20 centromeres in a cell at anaphase, how many chromosomes are there in each daughter
cell following cytokinesis?
A) 10
B) 20
C) 30
D) 40
E) 80
9) Where do the microtubules of the spindle originate during mitosis in both plant and animal cells?
A) centromere
B) centrosome
C) centriole
D) chromatid
E) kinetochore
10) Taxol is an anticancer drug extracted from the Pacific yew tree. In animal cells, Taxol disrupts
microtubule formation by binding to microtubules and accelerating their assembly from the protein
precursor, tubulin. Surprisingly, this stops mitosis. Specifically, Taxol must affect
A) the formation of the mitotic spindle.
B) anaphase.
C) formation of the centrioles.
D) chromatid assembly.
E) the S phase of the cell cycle.
11) Which of the following are primarily responsible for cytokinesis in plant cells but not in animal
cells?
A) kinetochores
B) Golgi-derived vesicles
C) actin and myosin
D) centrioles and centromeres
E) cyclin-dependent kinases
12) In which group of eukaryotic organisms does the nuclear envelope remain intact during mitosis?
A) seedless plants
B) dinoflagellates
C) diatoms
D) dinoflagellates and diatoms only
E) seedless plants, dinoflagellates, and diatoms
13) Movement of the chromosomes during anaphase would be most affected by a drug that
A) reduces cyclin concentrations.
B) increases cyclin concentrations.
C) prevents elongation of microtubules.
D) prevents shortening of microtubules.
E) prevents attachment of the microtubules to the kinetochore.
14) 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) G0
B) G1
C) S
D) G2
E) M
15) A group of cells is assayed for DNA content immediately following mitosis and is found to have an
average of 8 picograms of DNA per nucleus. How many picograms would be found at the end of S and
the end of G2?
A) 8; 8
B) 8; 16
C) 16; 8
D) 16; 16
E) 12; 16
16) For anaphase to begin, which of the following must occur?
A) Chromatids must lose their kinetochores.
B) Cohesin must attach the sister chromatids to each other.
C) Cohesin must be cleaved enzymatically.
D) Kinetochores must attach to the metaphase plate.
E) Spindle microtubules must begin to depolymerize.
17) Why do chromosomes coil during mitosis?
A) to increase their potential energy
B) to allow the chromosomes to move without becoming entangled and breaking
C) to allow the chromosomes to fit within the nuclear envelope
D) to allow the sister chromatids to remain attached
E) to provide for the structure of the centromere
18) Which of the following best describes how chromosomes move toward the poles of the spindle
during mitosis?
A) The chromosomes are “reeled in” by the contraction of spindle microtubules.
B) Motor proteins of the kinetochores move the chromosomes along the spindle microtubules.
C) Nonkinetochore spindle fibers serve to push chromosomes in the direction of the poles.
D) The chromosomes are “reeled in” by the contraction of spindle microtubules, and motor proteins of
the kinetochores move the chromosomes along the spindle microtubules.
E) The chromosomes are “reeled in” by the contraction of spindle microtubules, motor proteins of the
kinetochores move the chromosomes along the spindle microtubules, and nonkinetochore spindle fibers
serve to push chromosomes in the direction of the poles.
19) Which of the following is a function of those spindle microtubules that do not attach to
kinetochores?
A) maintaining an appropriate spacing among the moving chromosomes
B) producing a cleavage furrow when telophase is complete
C) providing the ATP needed by the fibers attached to kinetochores
D) maintaining the region of overlap of microtubules in the cell’s center
E) pulling the poles of the spindles closer to one another
20) During which phase of mitosis do the chromatids become chromosomes?
A) telophase
B) anaphase
C) prophase
D) metaphase
E) cytokinesis
21) Which of the following was a discovery that had to be made before human chromosomes could be
correctly counted?
A) how to use a hypotonic solution to swell nuclei
B) how to visualize sperm nuclei
C) how to visualize chromosomes
D) when to see chromosomes separate from one another
E) when to see chromosomes in pairs
22) Which of the following is (are) required for motor proteins to function in the movement of
chromosomes toward the poles of the mitotic spindle?
A) intact centromeres
B) an MTOC (microtubule organizing center)
C) a kinetochore attached to the metaphase plate
D) ATP as an energy source
E) synthesis of cohesin
23) What is a cleavage furrow?
A) a ring of vesicles forming a cell plate
B) the separation of divided prokaryotes
C) a groove in the plasma membrane between daughter nuclei
D) the metaphase plate where chromosomes attach to the spindle
E) the space that is created between two chromatids during anaphase
24) Which of the following proteins are involved in binary fission as well as eukaryotic mitotic division?
A) cyclins
B) Cdks
C) MPF
D) actin and tubulin
E) cohesins
25) Using which of the following techniques would enable your lab group to distinguish between a cell
in G2 and a cell from the same organism in G1?
A) fluorescence microscopy
B) electron microscopy
C) spectrophotometry
D) radioactive-labeled nucleotides
E) labeled kinetochore proteins
26) You have the technology necessary to measure each of the following in a sample of animal cells:
chlorophylls, organelle density, picograms of DNA, cell wall components, and enzymatic activity.
Which would you expect to increase significantly from M to G1?
A) organelle density and enzymatic activity
B) cell wall components and DNA
C) chlorophyll and cell walls
D) organelle density and cell walls
E) chlorophyll and DNA
27) A plant-derived protein known as colchicine can be used to poison cells by blocking the formation
of the spindle. Which of the following would result if colchicine is added to a sample of cells in G2?
A) The cells would immediately die.
B) The cells would be unable to begin M and stay in G2.
C) The chromosomes would coil and shorten but have no spindle to which to attach.
D) The chromosomes would segregate but in a disorderly pattern.
E) Each resultant daughter cell would also be unable to form a spindle.
28) What causes the decrease in the amount of cyclin at a specific point in the cell cycle?
A) an increase in production once the restriction point is passed
B) the cascade of increased production once its protein is phosphorylated by Cdk
C) the changing ratio of cytoplasm to genome
D) its destruction by a process initiated by the activity of its complex with a cyclin
E) the binding of PDGF to receptors on the cell surface
29) Which of the following is released by platelets in the vicinity of an injury?
A) PDGF
B) MPF
C) protein kinase
D) cyclin
E) Cdk
30) Which of the following is a protein synthesized at specific times during the cell cycle that associates
with a kinase to form a catalytically active complex?
A) PDGF
B) MPF
C) protein kinase
D) cyclin
E) Cdk
31) Which of the following is a protein maintained at constant levels throughout the cell cycle that
requires cyclin to become catalytically active?
A) PDGF
B) MPF
C) protein kinase
D) cyclin
E) Cdk
32) Which of the following triggers the cell’s passage past the G2 checkpoint into mitosis?
A) PDGF
B) MPF
C) protein kinase
D) cyclin
E) Cdk
33) The cyclin component of MPF is destroyed toward the end of which phase?
A) G0
B) G1
C) S
D) G2
E) M
34) Proteins that are involved in the regulation of the cell cycle, and that show fluctuations in
concentration during the cell cycle, are called
A) ATPases.
B) kinetochores.
C) kinases.
D) proton pumps.
E) cyclins.
35) The MPF protein complex turns itself off by
A) activating a process that destroys cyclin components.
B) activating an enzyme that stimulates cyclin.
C) binding to chromatin.
D) exiting the cell.
E) activating the anaphase-promoting complex.
36) 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.
37) Density-dependent inhibition is explained by which of the following?
A) As cells become more numerous, they begin to squeeze against each other, restricting their size and
ability to produce control factors.
B) As cells become more numerous, the cell surface proteins of one cell contact the adjoining cells and
they stop dividing.
C) As cells become more numerous, the protein kinases they produce begin to compete with each other,
such that the proteins produced by one cell essentially cancel those produced by its neighbor.
D) As cells become more numerous, more and more of them enter the S phase of the cell cycle.
E) As cells become more numerous, the level of waste products increases, eventually slowing down
metabolism.
38) Which of the following is true concerning cancer cells?
A) They do not exhibit density-dependent inhibition when growing in culture.
B) When they stop dividing, they do so at random points in the cell cycle.
C) They are not subject to cell cycle controls.
D) When they stop dividing, they do so at random points in the cell cycle, and they are not subject to
cell cycle controls.
E) When they stop dividing, they do so at random points in the cell cycle; they are not subject to cell
cycle controls; and they do not exhibit density-dependent inhibition when growing in culture.
39) Which of the following describe(s) cyclin-dependent kinase (Cdk)?
A) Cdk is inactive, or “turned off,” in the presence of cyclin.
B) Cdk is present throughout the cell cycle.
C) Cdk is an enzyme that attaches phosphate groups to other proteins.
D) Cdk is inactive, or “turned off,” in the presence of cyclin and it is present throughout the cell cycle.
E) Cdk is present throughout the cell cycle and is an enzyme that attaches phosphate groups to other
proteins.
40) A particular cyclin called cyclin E forms a complex with Cdk 2 (cyclin-dependent kinase 2). This
complex is important for the progression of the cell from G1 into the S phase of the cell cycle. Which of
the following statements is correct?
A) The amount of free cyclin E is greatest during the S phase.
B) The amount of free Cdk 2 is greater during G1 compared to the S phase.
C) The amount of free cyclin E is highest during G1.
D) The amount of free Cdk 2 is greatest during G1.
E) The activity of the cyclin E/Cdk 2 complex is highest during G2.
41) Cells from an advanced malignant tumor most often have very abnormal chromosomes, and often an
abnormal total number of chromosomes. Why might this occur?
A) Cancer cells are no longer density dependent.
B) Cancer cells are no longer anchorage dependent.
C) Chromosomally abnormal cells can still go through cell cycle checkpoints.
D) Chromosomally abnormal cells still have normal metabolism.
E) Transformation introduces new chromosomes into cells.
42) Besides the ability of some cancer cells to overproliferate, what else could logically result in a
tumor?
A) metastasis
B) changes in the order of cell cycle stages
C) lack of appropriate cell death
D) inability to form spindles
E) inability of chromosomes to meet at the metaphase plate
43) After which checkpoint is the cell first committed to continue the cell cycle through M?
A) G0
B) G1
C) G2
D) S
E) previous M