Chapter 12

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Transcript Chapter 12

Chapter 12
The Cell Cycle
Active Lecture Questions for use with Classroom Response Systems
Biology, Seventh Edition
Neil Campbell and Jane Reece
Edited by William Wischusen, Louisiana State University
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Using the data in the table below, the best conclusion concerning the
difference between the cell types is:
Minutes Spent in Cell Cycle Phases
Cell Type
G1
S
G2
M
Beta
18
24
12
16
Delta
100
0
0
0
18
48
14
20
Gamma
a)
beta and gamma contain the same amount of DNA.
b)
beta contains more RNA than gamma.
c)
gamma contains 48 times more DNA and RNA than beta.
d)
beta has less DNA than gamma, but more than delta
e)
Delta cells can be found in quickly regenerating tissues
Copyright © 2004 Pearson Education, Inc. publishing as Benjamin Cummings
Cytokinesis usually, but not always, follows mitosis.
If a cell completed mitosis but not cytokinesis, what
would be the result?
a) a cell with a single large nucleus
b) a cell with high concentrations of actin
and myosin
c) a cell with two abnormally small nuclei
d) a cell with two nuclei
e) a cell with two nuclei but with half the
amount of DNA
Copyright © 2004 Pearson Education, Inc. publishing as Benjamin Cummings
The decline of MPF activity at the end of mitosis is
caused by:
a. The destruction of the protein kinase (Cdk)
b. Decreased synthesis of cyclin
c. The degradation of cyclin
d. Synthesis of DNA
e. An increase in the cell’s volume-to-genome ratio
Copyright © 2004 Pearson Education, Inc. publishing as Benjamin Cummings
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 was the
nucleus with 6 picograms of DNA?
a) G0
b) G1
c) S
d) G2
e) M
Copyright © 2004 Pearson Education, Inc. publishing as Benjamin Cummings
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. Those cells would have
__________ picograms at the end of the S phase and
__________ picograms at the end of G2.
a) 8 ... 8
b) 8 ... 16
c) 16 ... 8
d) 16 ... 16
e) 12 ... 16
Copyright © 2004 Pearson Education, Inc. publishing as Benjamin Cummings
A particular cell has half as much DNA as some
of the other cells in a mitotically active tissue.
The cell in question is most likely in
a) G1.
b) G2.
c) prophase.
d) metaphase.
e) anaphase.
Copyright © 2004 Pearson Education, Inc. publishing as Benjamin Cummings
A cell in which of the following phases would
have the least amount of DNA?
a) G0
b) G2
c) prophase
d) metaphase
e) anaphase
Copyright © 2004 Pearson Education, Inc. publishing as Benjamin Cummings
Which of the following statements about mitosis is not true?
a.
Mitosis occurs after DNA replication
b.
Mitosis is followed by cytokinesis, producing 2 genetically
identical daughter cells
c.
Mitosis plays a role in growth, repair, and asexual reproduction
d.
In mitosis, only half of one’s genome is passed from the parent
cell to daughter cells
e.
Mitosis is a continuous process with observable structural
features. The general order of the processes are replication,
alignment, and separation of chromosomes.
Copyright © 2004 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2004 Pearson Education, Inc. publishing as Benjamin Cummings
10. The rhythmic changes in cyclin concentration in a cell
cycle are due to
a)
its increased production once the restriction point is
passed.
b)
the cascade of increased production once its enzyme is
phosphorylated by MPF.
c)
its degradation, which is initiated by active MPF.
d)
the correlation of its production with the production of
Cdk.
e)
the binding of the growth factor PDGF.
Copyright © 2004 Pearson Education, Inc. publishing as Benjamin Cummings