 |
General
---------Biology----------------------------------------------------- ------------------Online--------------------------------------- |
1. What causes the rhythmic change in cyclin concentration in the cell
cycle?
a. an increase in production once the restriction point is passed.
b. the cascade of increased production once its enzyme is
phosphorylated by cdc2.
c. the changing ratio of cytoplasm to genome.
d. its destruction by an enzyme activated at the end of mitosis.
e. the binding of PDGF to receptors on the cell surface.
2. A cell that passes the restriction point
(the G1 Checkpoint) will most likely
a. move into prophase of mitosis.
b. undergo chromosome duplication.
c. stop dividing.
d. show a drop in MPF concentration.
e. have just completed cytokinesis to separate
into two new cells.
3. Which of the following organisms does not reproduce
cells by
mitosis and cytokinesis?
a. cow
b. bacterium
c. mushroom
d. cockroach
e. banana tree
4. Cytokinesis usually, but not always, follows mitosis.
If cells
undergo mitosis and not cytokinesis, this
would result in
a. a cell with a single large nucleus.
b. a cell with two or more nuclei.
c. cells with abnormally small nuclei.
d. feedback responses that prevent mitosis.
e. death of the cell line.
5. If there are 12 chromosomes in an animal cell in
G 1 stage of the
cell cycle, what is the diploid number of
chromosomes for this
organism?
a. 6
b. 12
c. 24
d. 36
e. 48
6. Regarding mitosis and cytokinesis, one difference
between higher
plants and animals is that in plants
a. the spindles contain microfibrils in addition
to microtubules,
whereas animal spindles
do not contain microfibrils.
b. sister chromatids are identical, but they
differ from one another
in animals.
c. a cell plate begins to form at telophase,
whereas in animals a
cleavage furrow is initiated
at that stage.
d. chromosomes become attached to the spindle
at prophase, whereas
in animals chromosomes do
not become attached until anaphase.
e. spindle poles contain centrioles, whereas
spindle poles in
animals do not.
7. How do the daughter cells at the end of mitosis
and cytokinesis
compare with their parent cell when it was
in G 1 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 may have new combinations
of genes due to
crossing over.
8. Cells that have stopped dividing and are differentiating
are
a. cancer cells.
b. in the G 2 phase of the cell cycle.
c. in the G 1 phase of the cell cycle.
d. in the S phase of the cell cycle.
e. in the M phase of the cell cycle.
9. 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.
One nucleus had 5
picograms of DNA. What stage of the cell cycle
was this nucleus in?
a. G 0
b. G 1
c. S
d. G 2
e. M
------------------------------
Omit 10 - 14.
Answer the question(s) below that consist
of five phrases or
sentences related to the control of cell
division. For each one,
select the term from below that is most
closely related to it. Each
term may be used once, more than once,
or not at all.
1. PDGF
2. MPF
3. protein kinase
4. cyclin
5. cdc2
10. Released by platelets in
the vicinity of an injury.
a. 1
b. 2
c. 3
d. 4
e. 5
11. A family of enzymes that
catalyzes the transfer of a phosphate
group from ATP to target
proteins.
a. 1
b. 2
c. 3
d. 4
e. 5
12. Fibroblasts have receptors
for this substance on their plasma
membranes.
a. 1
b. 2
c. 3
d. 4
e. 5
13. A substance synthesized
through the cell cycle that accumulates
during early interphase
and associates with another protein to
form active enzymes.
a. 1
b. 2
c. 3
d. 4
e. 5
14. Triggers the activation
of numerous proteins that facilitate
mitosis.
a. 1
b. 2
c. 3
d. 4
e. 5
------------------------------
Answer the question(s) below that consist of five phrases or
sentences concerned with the cell cycle. For each phrase or
sentence, select the answer that is most closely related to it.
Each answer be used once, more than once, or not at all.
a. G 0
b. G 1
c. S
d. G 2
e. M
15. The "restriction point" ("go no-go" or G1 checkpoint)
occurs here.
16. Nerve and muscle cells are in this phase.
17. The shortest part of the cycle.
18. Chromosomes are duplicated during this phase.
19. Cyclin is destroyed toward the end of this phase.
---------------------------
20. The formation of a cell plate is beginning across
the middle of a
cell and nuclei are reforming at opposite
ends of the cell. What
kind of a cell is this?
a. an animal cell in metaphase
b. an animal cell in telophase
c. an animal cell undergoing cytokinesis
d. a plant cell in metaphase
e. a plant cell undergoing cytokinesis
------------------------------
Refer to the terms below to answer the following question(s).
Each
term may be used once, more than once, or not at all.
a. telophase
b. anaphase
c. prometaphase
d. metaphase
e. prophase
21. Two centrosomes are arranged at opposite poles of the cell.
22. Centrioles begin to move apart in animal cells.
23. This is the longest of the mitotic stages.
24. Centromeres uncouple, sister chromatids are separated,
and the two
new chromosomes move to opposite poles of
the cell.
-------------------------
25. The centromere is a region in which
a. chromatids are attached to one another.
b. metaphase chromosomes become aligned.
c. chromosomes are grouped during telophase.
d. the nucleus is located prior to mitosis.
e. new spindle microtubules form.
26. 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
27. All of the following are characteristic of telophase
of mitosis
EXCEPT:
a. Cytokinesis begins.
b. Each chromosome is made of two chromatids.
c. The nuclear envelope reappears.
d. Chromosomes begin to uncoil.
e. Spindel microtubules disappear.
28. A cell containing 92 chromatids at the start of
mitosis would, at
its completion, produce cells containing how
many chromosomes?
a. 12
b. 16
c. 23
d. 46
e. 92
29. During which phase of mitosis are chromosomes found
composed of two
chromatids found?
a. from interphase through anaphase
b. from G 1 of interphase through metaphase
c. from metaphase through telophase
d. from anaphase through telophase
e. from G 2 of interphase through metaphase
30. If there are 20 centromeres in a cell, how many
chromosomes are
there?
a. 10
b. 20
c. 30
d. 40
e. 80
31. All of the following occur during the latter stages
of mitotic
prophase EXCEPT:
a. The centrioles move apart.
b. The nucleolus disintegrates.
c. The nuclear envelope disappears.
d. Chromosomes are duplicated.
e. The spindle is organized.
32. If there are twelve chromosomes in a cell in G
1 of the cell cycle,
what is the diploid number of chromosomes?
a. 6
b. 12
c. 24
d. 36
e. 48
33. If the haploid number for a species is 3, each
dividing diploid cell
will have how many chromatids at metaphase?
a. 3
b. 6
c. 9
d. 12
e. 18
34. All of the following occur during mitosis EXCEPT
a. the coiling of chromosomes.
b. the division of centromeres.
c. the formation of a spindle.
d. the synthesis of DNA.
e. the degradation of the nuclear envelope.
35. How many chromosomes will a cell have during mitotic
anaphase if the
diploid chromosome number is 4?
a. 1
b. 2
c. 4
d. 8
e. 16
------------------------------
------------------------------
. Use the data in Table 11.1 to answer questions
36 and 37.
The data below were obtained from a study of the length of time
spent in each phase of the cell cycle of three eukaryotic organisms,
designated beta, delta, and gamma.
Table 11.1 Minutes Spent in Cell Cycle Phases
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
36. Of the following, the best conclusion concerning
the difference
between the S phases for beta and gamma is
that
a. gamma contains more chromosomes than beta.
b. beta and gamma contain the same number
of chromosomes.
c. beta contains more chromosomes 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.
37. The best conclusion concerning delta is that the
cells
a. contain no DNA.
b. contain no RNA.
c. contain only one chromosome that is very
short.
d. are actually in the G0 phase, like most
nerve cells
e. divide in the G1 phase.
----------------------------
38. The S phase could be measured by
a. counting the number of cells.
b. determining the start and stop of increased
DNA in the cells.
c. synthesis versus breakdown of S protein.
d. synthesis of the S chromosome.
e. stopping G1.
39. Enzymes that control the activities of other proteins
by phorphorylating them are called
a. ATPases.
b. microtubules.
c. kinetochores.
d. chromatin.
e. protein kinases.
40. 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. centrioles.
d. proton pumps.
e. cyclins.
41. The MPF protein complex turns itself off by
a. activating an enzyme that destroys cyclin.
b. activating an enzyme that stimulates cyclin.
c. binding to chromatin.
d. exiting the cell.
e. None of these is true; MPF is always active.
42. Recent research has indicated that cancer cells
a. transform normal cells by altering genes
involved in the control
of mitosis.
b. always develop into a tumor.
c. contain more than the normal number of
chromosomes.
d. are unable to complete the cell cycle after
the S phase.
e. enter and exit the G 0 phase three times
before they divide.
43. Colchicine is a drug that binds to the protein
that forms
microtubules, thereby preventing microtubules
from forming.
Colchicine has been used to study mitosis
because it stops the
process. Most likely this is due to
a. prevention of sister chromatid formation.
b. prevention of kinetochore formation.
c. inhibition of DNA synthesis.
d. alteration of centriole structure.
e. prevention of cell-plate formation.
44. Which of the following is NOT true of the bacterial
chromosome? It
a. contains a single, circular DNA molecule.
b. is associated with proteins.
c. floats freely inside the bacterial cell.
d. is highly folded within the cell.
e. has genes that control binary fission.
45. A cell with 20 chromosomes (diploid number) goes
through the cell
cycle. The number of unique chromosomes after
doubling the DNA in the S
phase is
a. 20.
b. 40.
c. 10.
d. called the S number of chromosomes.
e. called haploid.
46. 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 fibers of the mitotic spindle.
b. anaphase.
c. formation of the centrioles.
d. chromatid assembly.
e. the S phase of the cell cycle.
General Biology Online!
Copyright © 1999 by Bill Wilcox
941 637-5639