cell cycle

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For Questions 13–16, match the description of the event with the phase of mitosis in which it
occurs. Each phase may be used more than once.
Event
13. The chromosomes separate and begin to move to
opposite sides of the cell.
14. The chromosomes become visible. The centrioles take
up positions on opposite sides of the nucleus.
15. A nuclear envelope re-forms around each cluster of
chromosomes. The nucleolus becomes visible in each
daughter nucleus.
16. The chromosomes line up across the center of the cell.
Phase of Mitosis
A. Telophase
B. Prophase
C. Metaphase
D. Anaphase
Which of the following represents the correct order of the phases of the cell cycle?
A)
G1 -> G2 -> S -> M
B)
G1 -> G2 -> M -> S
C)
G1 -> S -> G2 -> M
D)
G1 -> S -> M -> G2
E)
G1 -> M -> G2 -> S
The division of the cytoplasm is called
A)
synapsis.
B)
mitosis.
C)
meiosis.
D)
cytokinesis.
E)
cytogenetics.
Which of the following represents the correct order of the phases of mitosis?
A)
prophase -> anaphase -> metaphase -> telophase
B)
prophase -> metaphase -> anaphase -> telophase
C)
prophase -> metaphase -> telophase -> anaphase
D)
metaphase -> prophase -> telophase -> anaphase
E)
metaphase -> prophase -> anaphase -> telophase
The sister chromatids separate during ________ of mitosis.
A)
telophase
B)
metaphase
C)s
anaphase
D)
interphase
E)
prophase
The chromosomes start to condense as the cell enters ________ of mitosis.
A)s
interphase
B)
S phase
C)
anaphase
D)
metaphase
E)
cytokinesis
The _______ serve(s) to identify the two poles of the cell during mitosis.
A)
kinetochores
B)
centromeres
C)
metaphase plate
D)
nuclear envelope
E)s
centrosomes
Which of the following events do NOT occur in prophase of mitosis?
A)
DNA condenses to form chromosomes
B)
nuclear membrane breaks down
C)
nucleolus breaks down
D)s
chromosomes are replicated
E)
mitotic spindle begins to form
The mitotic spindle fibers attach to chromosomes via special structures termed
A)
centrioles.
B)
asters.
C)s
kinetochores.
D)
centrosomes.
E)
keratins.
Which of the following statements about microtubules during anaphase is TRUE?
A)
those attached to chromosomes elongate, while those that are unattached
B)s
those attached to chromosomes shorten, while those that are unattached
C)
both attached and unattached microtubules shorten
D)
both attached and unattached microtubules elongate
E)
both attached and unattached microtubules elongate at first and then
shorten
elongate
shorten
The success of DNA replication is assessed during the ______ phase.
A)
G1
B)
M
C)
C
D)
S
E)s
G2
The cell cycle is regulated by checkpoints during the _______ phases.
A)
G1, S and G2
B)
G1, S and C
C)s
G1, G2, and M
D)
G1, S and M
E)
G1, S, G2 and M
A eukaryotic cell that receives a “go-ahead” signal at the G1 checkpoint of the cell cycle will
A)s
complete the cycle and divide.
B)
move directly into the M phase.
C)
move directly into the G2 phase.
D)
enter a resting stage.
E)
stop growing.
Proteins that stimulate cell division include
A)
caspases.
B)
cyclins.
C)
cyclin-dependent kinases.
D)
caspases and cyclins.
E)s
cyclins and cyclin-dependent kinases.
During which phase of meiosis does crossing over occur?
A)s
Prophase I
B)
Metaphase I
C)
Prophase II
D)
Metaphase II
E)
Crossing over occurs throughout meiosis I
Which of the following is NOT a requirement for cells to undergo meiotic division? (p. 207)
A)
The organism must have pairs of each chromosome
B)
The cell must be a eukaryote
C)s
The organism must be an animal
D)
Gametes are required at some stage of the organism's life cycle
E)
All of the statements are true requirements for meiosis to occur
Why do homologous chromosomes pair in prophase I and not in prophase II? (p. 208)
A)
Pairing of chromosomes requires precision and it would take too much
metabolic energy to pair them twice.
B)
during meiosis I.
C)s
The kinetochores have been used up after separating the sister chromatids
The cells are haploid during prophase II and therefore can't pair.
D)
Meiosis I is more like mitosis than meiosis II is, and so the chromosomes pair
up similarly in meiosis I and mitosis.
E)
Two of the above are correct
An error in meiosis that results in an abnormal number of chromosomes in the final haploid cell
(p.214)
A)
occurs only if separation of chromosomal material occurs in meiosis I.
B)
occurs only if separation of chromosomal material occurs in meiosis II.
C)
is a condition called aneuploidy.
D)
Two of the above are true
E)s
All of the above are true
If cyclin B levels dropped dramatically after meiosis I, what outcome can be said with the most
certainty? (p. 216)
A)s
during prophase I.
The DNA content of the cells would be half that of the meiotic mother cell
B)
The cell would die.
C)
The cells produced at the completion of meiosis would have less DNA than
D)
Meiosis II would be even more similar to mitosis.
E)
Two mitotic divisions would immediately result upon the completion of
normal.
meiosis.
Centromeres divide in
A)
mitosis and meiosis I.
B)s
mitosis and meiosis II.
C)
meiosis II only.
D)
meiosis I and meiosis II.
E)
mitosis, meiosis I and meiosis II.
Which of the following describes meiosis II in humans?
A)
4N -> 2N
B)
2N -> 2N
C)
2N -> 1N
D)
1N -> 2N
E)s
1N -> 1N
Arrange the following events in the proper order in which they occur during meiosis I.
1 = Separation of homologous chromosomes
2 = Synapsis
3 = Crossing-over
4 = Independent assortment
A)
1, 2, 3, 4
B)
1, 3, 2, 4
C)
2, 3, 1, 4
D)s
2, 3, 4, 1
E)
2, 4, 3, 1
Synapsis is the side-by-side alignment of
A)
sister chromatids of a chromosome.
B)s
homologous chromosomes.
C)
non-homologous chromosomes.
D)
spindle fibers.
E)
nuclei prior to the division of the cytoplasm.
At the end of meiosis I, each daughter cell is
A)
diploid, and each chromosome consists of a single chromatid.
B)
diploid, and each chromosome consists of two chromatids.
C)
haploid, and each chromosome consists of a single chromatid.
D)s
haploid, and each chromosome consists of two chromatids.
E)
haploid, containing a mixture of single- and double-chromatid
chromosomes.
During anaphase I of meiosis, ____I____ move towards opposite cell poles, whereas during
anaphase II of meiosis, ____II____ are separated.
A)
I = sister chromatids ; II = non-sister chromatids
B)
I = sister chromatids ; II = homologous chromosomes
C)s
I = homologous chromosomes ; II = sister chromatids
D)
I = homologous chromosomes ; II = non-sister chromatids
E)
I = homologous chromosomes ; II = non-homologous chromosomes
Which of the following features are unique to meiosis?
A)
synapsis
B)
homologous recombination
C)
reduction division
D)
A and B
E)s
A, B and C
A crossover in meiosis is an exchange of genetic material between
A)
sister chromatids of the same chromosome.
B)
sister chromatids of homologous chromosomes.
C)
sister chromatids of non-homologous chromosomes.
D)s
non-sister chromatids of homologous chromosomes.
E)
non-sister chromatids of non-homologous chromosomes.
The four daughter cells produced in meiosis
A)
are diploid just like the parent cell.
B)
have double the number of chromosomes as the parent cell.
C)
have one-fourth the number of chromosomes of the parent cell.
D)s
have one of each pair of chromosomes found in the parent cell.
E)
have identical chromosomes.
A crossover in meiosis is an exchange of genetic material between
A)
sister chromatids of the same chromosome.
B)
sister chromatids of homologous chromosomes.
C)
sister chromatids of non-homologous chromosomes.
D)s
non-sister chromatids of homologous chromosomes.
E)
non-sister chromatids of non-homologous chromosomes.
A tetrad is made up of
A)
four non-homologous chromosomes.
B)
four non-homologous chromatids.
C)
four homologous pairs of chromosomes.
D)
two homologous pairs of chromosomes.
E)s
two homologous chromosomes, each consisting of two chromatids.
Which of the following statements about crossing over is TRUE?
A)
It occurs only in males.
B)
It occurs only in some chromosomes.
C)
It occurs only between genes that are heterozygous.
D)
It results in reduced genetic variation among gametes.
E)s
None of the above
Which of the following events occur during prophase I?
A)
down of nuclear envelope
B)
condensation of chromosomes
C)
movement of centrosomes
D)
A and B
E)s
A, B and C
How many bivalents are formed in a cell with 20 chromosomes at the beginning of meiosis I?
A)
1
B)
5
C)s
10
D)
20
E)
40
Which of the following events occur during anaphase I?
A)s
separation of homologous chromosomes
B)
formation of synaptonemal complex
C)
lengthening of kinetochore microtubules
D)
A and B
E)
A, B and C
The spindle apparatus is fully formed by the end of
A)
metaphase II.
B)
anaphase II.
C)
prophase II.
D)s
prometaphase II.
E)
telophase II.
Separation of ________ occurs in anaphase II of meiosis.
A)
non-homologous chromosomes
B)
homologous chromosomes
C)
non-sister chromatids
D)s
sister chromatids
E)
the two nuclei
At the end of meiosis II, there are
A)
two haploid cells, with each chromosome containing two sister chromatids.
B)
two haploid cells, with each chromosome consisting of a single chromatid.
C)
four haploid cells, with each chromosome containing two sister chromatids.
D)s
four haploid cells, with each chromosome consisting of a single chromatid.
E)
four diploid cells, with each chromosome consisting of a single chromatid.
The number of cells produced by meiosis is ________ the number of cells produced by mitosis.
A)
one-fourth
B)
half
C)
equal to
D)s
twice
E)
four times
The number of chromosomes in daughter cells produced by meiosis is ________ the number of
chromosomes in daughter cells produced by mitosis.
A)
one-fourth
B)s
half
C)
equal to
D)
twice
E)
four times
Which of the following is unique to meiosis?
A)
nuclear membrane breaks down
B)
DNA organizes into chromosomes
C)s
crossing-over
D)
chromosomes align along the central plate of the cell
E)
none of the above
Random orientation of homologous chromosomes occurs in ________ of meiosis.
A)
prophase I
B)s
metaphase I
C)
anaphase I
D)
prophase II
E)
metaphase II
Consider a cell that has four pairs of chromosomes. What is the number of possible chromosome
orientations in that cell?
A)
4
B)
8
C)s
16
D)
24
E)
32
Consider a cell that has three pairs of chromosomes. What fraction of the gametes produced from
this cell will contain only maternal chromosomes?
A)
1/2
B)
1/4
C)
1/6
D)s
1/8
E)
1/12
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