Ch9 cell cycle and mitosis
True/False
Indicate whether the statement is true or false.
____
1. Diffusion over large distances is slow and inefficient because it relies on random movement of
molecules and ions.
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2. The cell cycle is divided into interphase and mitosis.
____
3. During prophase in an onion root tip cell, centrioles migrate to the poles of the cell.
____
4. In plant cells, cytokinesis begins with a furrow that pinches the cell.
____
5. The length of the cell cycle is the same for all cells
____
6. Cells are small because it is more efficient to transport and communicate short distances
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7. Interphase is divided into 3 phases
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8. The cell cycle has 2 checkpoints
____
9. The structure on a chromosome where sister chromatids attach is the centromere.
_________________________
____ 10. Prophase is the last phase of mitosis and is the shortest phase
____ 11. Two chromatids with the exact DNA info are called sister chromatids
____ 12. Cyclins bind with cyclin-dependent kinases to initiate different stages in mitosis.
_____13. Cancer cells have lost the ability to preform apoptosis
_____ 14. The checkpoint right before S-Phase checks the environment to see if it’s ok to divide.
_____15. Chromosomes come from chromatin
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____ 13. By the end of prophase, each of the following has occurred except ____.
a. tighter coiling of the chromosomes
b. breaking down of the nuclear envelope
c. disappearing of the nucleolus
d. lining up of chromosomes in the cell
____ 14. The chromosomes shown in Figure 9-1 are in which state of mitosis?
Figure 9-1
a. prophase
b. metaphase
c. anaphase
d. telophase
Figure 9-2
____ 15. Which of the cells depicted in the line graph in Figure 9-2 are most likely cancerous?
a. A
c. C
b. B
d. D
____ 16. If cancer is present, what is the likely explanation for what happened to the cells depicted in the
curves labeled B and D in Figure 9-2?
a. They thrived with the cancerous cells.
b. They were unaffected
c. They died off
d. None of the above
____ 17. Which of the following does not occur as a cell grows larger and larger in size?
a. difficulty obtaining nutrients
b. difficulty eliminating wastes
c. ratio of surface area to volume increases
d. diffusion gets more efficient
____ 19. Why is the synthesis stage in the cell cycle called this?
a. because protein synthesis is taking place
b. because DNA synthesis is taking place
c. because it combines several smaller stages into one
d. because the chromosomes come together
____ 20. Which of these has occurred by the end of prophase?
a. Sister chromatids are separated.
b. The spindle is beginning to form.
c. The cell membrane has begun to pinch inward.
d. The nuclear membrane has disappeared.
Figure 9-4
____ 21. Figure 9-4 illustrates which stage of mitosis?
a. anaphase
c. prophase
b. metaphase
d. telophase
____ 22. How is the alignment of chromosomes, shown in Figure 9-4, on the equatorial plate of the cell
maintained?
a. They are always located there, since that is where the nucleus was.
b. Tension between opposite spindle fibers pulls them there.
c. The pressure of the cytoplasm moves them there.
d. The chromosomes are attracted to each other and meet there.
____ 23. Which of the following occurs in telophase?
a. chromosomes condense
b. chromosomes line up
c. chromosomes move to opposite poles
d. chromosomes relax
____ 24. A cell has 12 chromosomes. How many chromosomes will each daughter cell have?
a. 4
c. 12
b. 6
d. 24
____ 25. A cell that is undergoing mitosis is examined with a light microscope. An observation that would
allow for identification of the cell as an animal cell rather than a plant cell would be
a. the centrioles migrating.
b. the chromosome pairs separating from each other.
c. the chromosomes twisting about each other.
d. the nucleoli disappearing.
____ 26. The cell cycle is regulated by
a. cyclins
c. hormones
b. enzymes
d. sugars
____ 27. Cancer cells can reproduce rapidly because they
a. are smaller than normal cells.
b. bypass interphase.
c. undergo mitosis faster
d. spend less time in interphase, no need to check anything
____ 29. Prokaryotes divide by binary fission, a form of asexual reproduction in which
a. the nucleus divides into two nuclei.
b. the number of chromosomes in the cell is reduced.
c. a cell divides into two cells with identical genetic information.
d. spindle fibers attach to the poles of the cell.
____ 30. It is often said that normal cells change into cancerous cells frequently in our bodies. Which of
the following explanations accounts for the relative rarity of cancer?
a. The cancerous cells die on their own.
b. The DNA repair system fixes the mutation that causes cancer.
c. The cancer cells grow only very slowly at first.
d. The cancerous cells are normally crowded out by normal cell growth.
____ 31. What is the role of cyclin-dependent kinases in the cell cycle?
a. They stop the cycle if something has gone wrong.
b. They catalyze the condensation of the chromosomes.
c. They provide the energy for the actions of the spindle fibers.
d. They initiate various stages of the cell cycle.
Figure 9-5
____ 32. The cell in Figure 9-5 is undergoing mitosis. Which stage of mitosis will follow this one?
a. anaphase
c. prophase
b. metaphase
d. telophase
____ 33. Which checkpoint checks out the environment to see if cell survival can occur?
a. near the end of gap 1, monitoring DNA damage
b. during the S stage
c. At the end of G2 right before the M-phase
d. during mitosis, monitoring spindle formation
____ 34. DNA replication occurs during
a. anaphase.
c. metaphase.
b. interphase.
d. prophase.
____ 35. If you were studying the causes of cancer, which topic might interest you?
a. cyclin-dependent kinases
b. centromere structure
c. spindle-fiber structure
d. cell membranes
____ 36. Which of the phases of mitosis has the shortest duration?
a. anaphase
c. metaphase
b. cytokinesis
d. Prophase
____ 38. Why is it important for the chromosomes to condense during mitosis?
a. to facilitate DNA replication
b. to facilitate chromosome movement
c. to facilitate cytokinesis
d. to facilitate spindle formation
____ 39. The typical growth period of a cell occurs during which stage of the cell cycle?
a. G1 or Gap 1
c. synthesis
b. G2 or Gap 2
d. mitosis
____ 41. Colchicine is a chemical that when applied to a cell during mitosis can be used to “freeze” cells in
metaphase by preventing the chromosomes from moving away from the metaphase plate. What
part of the cell does colchicine most likely affect?
a. chromosome structure
c. nuclear membrane
b. spindle fibers
d. cell membrane