Question 1

All cell cycle checkpoints are similar in which way?

Accepted Answer

A)  They respond to the same cyclins. 
B)  They utilize the same Cdks. 
C)  They give the go-ahead signal to progress to the next checkpoint. 
D)  They each have only one cyclin/Cdk complex. 
E)  They activate or inactivate other proteins. 
A)  They respond to the same cyclins. 
B)  They utilize the same Cdks. 
C)  They give the go-ahead signal to progress to the next checkpoint. 
D)  They each have only one cyclin/Cdk complex. 
E)  They activate or inactivate other proteins. E

Question 2

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?

Accepted Answer

A)  PDGF 
B)  MPF 
C)  protein kinase 
D)  cyclin 
E)  Cdk 
A)  PDGF 
B)  MPF 
C)  protein kinase 
D)  cyclin 
E)  Cdk D

Question 3

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?

Accepted Answer

A)  fluorescence microscopy 
B)  electron microscopy 
C)  spectrophotometry 
D)  radioactive-labeled nucleotides 
E)  labeled kinetochore proteins 
A)  fluorescence microscopy 
B)  electron microscopy 
C)  spectrophotometry 
D)  radioactive-labeled nucleotides 
E)  labeled kinetochore proteins D

Question 4

What explains anchorage dependence of animal cells in vitro or in vivo?

Accepted Answer

A)  attachment of spindle fibers to centrioles 
B)  response of the plasma membrane to cell cycle controls 
C)  the makeup of the extracellular matrix of the substrate 
D)  the binding of cell-surface phospholipids to those of adjoining cells 
E)  the binding of cell-surface phospholipids to the substrate 
A)  attachment of spindle fibers to centrioles 
B)  response of the plasma membrane to cell cycle controls 
C)  the makeup of the extracellular matrix of the substrate 
D)  the binding of cell-surface phospholipids to those of adjoining cells 
E)  the binding of cell-surface phospholipids to the substrate

Question 5

The MPF protein complex turns itself off by

Accepted Answer

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. 
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.

Question 6

The following questions are based on Figure 12.3.
   
Figure 12.3
-Which number represents DNA synthesis?

Accepted Answer

A)  I 
B)  II 
C)  III 
D)  IV 
E)  V 
A)  I 
B)  II 
C)  III 
D)  IV 
E)  V

Question 7

For anaphase to begin, which of the following must occur?

Accepted Answer

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. 
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.

Question 8

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?

Accepted Answer

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. 
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.

Question 9

Which of the following describe(s)cyclin-dependent kinase (Cdk)?

Accepted Answer

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. 
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.

Question 10

Use the following information to answer the questions below.
Nucleotides can be radiolabeled before they are incorporated into newly forming DNA and can therefore be assayed to track their incorporation. In a set of experiments, a student-faculty research team used labeled T nucleotides and introduced these into the culture of dividing human cells at specific times.
-The research team used the setup to study the incorporation of labeled nucleotides into a culture of lymphocytes and found that the lymphocytes incorporated the labeled nucleotide at a significantly higher level after a pathogen was introduced into the culture. They concluded that

Accepted Answer

A)  the presence of the pathogen made the experiment too contaminated to trust the results. 
B)  their tissue culture methods needed to be relearned. 
C)  infection causes lymphocytes to divide more rapidly. 
D)  infection causes cell cultures in general to reproduce more rapidly. 
E)  infection causes lymphocyte cultures to skip some parts of the cell cycle. 
A)  the presence of the pathogen made the experiment too contaminated to trust the results. 
B)  their tissue culture methods needed to be relearned. 
C)  infection causes lymphocytes to divide more rapidly. 
D)  infection causes cell cultures in general to reproduce more rapidly. 
E)  infection causes lymphocyte cultures to skip some parts of the cell cycle.

Question 11

Why do neurons and some other specialized cells divide infrequently?

Accepted Answer

A)  They no longer have active nuclei. 
B)  They no longer carry receptors for signal molecules. 
C)  They have been shunted into G₀. 
D)  They can no longer bind Cdk to cyclin. 
E)  They show a drop in MPF concentration. 
A)  They no longer have active nuclei. 
B)  They no longer carry receptors for signal molecules. 
C)  They have been shunted into G₀. 
D)  They can no longer bind Cdk to cyclin. 
E)  They show a drop in MPF concentration.

Question 12

Density-dependent inhibition is explained by which of the following?

Accepted Answer

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. 
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.

Question 13

At the M phase checkpoint, the complex allows for what to occur?

Accepted Answer

A)  Separase enzyme cleaves cohesins and allows chromatids to separate. 
B)  Cohesins alter separase to allow chromatids to separate. 
C)  Kinetochores are able to bind to spindle microtubules. 
D)  All microtubules are made to bind to kinetochores. 
E)  Daughter cells are allowed to pass into G₁. 
A)  Separase enzyme cleaves cohesins and allows chromatids to separate. 
B)  Cohesins alter separase to allow chromatids to separate. 
C)  Kinetochores are able to bind to spindle microtubules. 
D)  All microtubules are made to bind to kinetochores. 
E)  Daughter cells are allowed to pass into G₁.

Question 14

Use the following information to answer the questions below.
Nucleotides can be radiolabeled before they are incorporated into newly forming DNA and can therefore be assayed to track their incorporation. In a set of experiments, a student-faculty research team used labeled T nucleotides and introduced these into the culture of dividing human cells at specific times.
-Once they had determined which cells were dividing, the team wanted to use a non-radioactive method to track whether various physiological factors (such as food or body temperature)affect the action of the pathogen. Which of the following would be effective, simple, and safe?

Accepted Answer

A)  measuring picograms of DNA 
B)  measuring numbers of chromosomes 
C)  measuring numbers of chromatids 
D)  counting the frequency of cells in mitosis 
E)  counting newly formed plasma membranes 
A)  measuring picograms of DNA 
B)  measuring numbers of chromosomes 
C)  measuring numbers of chromatids 
D)  counting the frequency of cells in mitosis 
E)  counting newly formed plasma membranes

Question 15

The cyclin component of MPF is destroyed toward the end of which phase?

Accepted Answer

A)  G₀ 
B)  G₁ 
C)  S 
D)  G₂ 
E)  M 
A)  G₀ 
B)  G₁ 
C)  S 
D)  G₂ 
E)  M

Question 16

Vinblastine is a standard chemotherapeutic drug used to treat cancer. Because it interferes with the assembly of microtubules, its effectiveness must be related to

Accepted Answer

A)  disruption of mitotic spindle formation. 
B)  inhibition of regulatory protein phosphorylation. 
C)  suppression of cyclin production. 
D)  myosin denaturation and inhibition of cleavage furrow formation. 
E)  inhibition of DNA synthesis. 
A)  disruption of mitotic spindle formation. 
B)  inhibition of regulatory protein phosphorylation. 
C)  suppression of cyclin production. 
D)  myosin denaturation and inhibition of cleavage furrow formation. 
E)  inhibition of DNA synthesis.

Question 17

The drug cytochalasin B blocks the function of actin. Which of the following aspects of the cell cycle would be most disrupted by cytochalasin B?

Accepted Answer

A)  spindle formation 
B)  spindle attachment to kinetochores 
C)  DNA synthesis 
D)  cell elongation during anaphase 
E)  cleavage furrow formation and cytokinesis 
A)  spindle formation 
B)  spindle attachment to kinetochores 
C)  DNA synthesis 
D)  cell elongation during anaphase 
E)  cleavage furrow formation and cytokinesis

Question 18

Which of the following proteins are involved in binary fission as well as eukaryotic mitotic division?

Accepted Answer

A)  cyclins 
B)  Cdks 
C)  MPF 
D)  actin and tubulin 
E)  cohesins 
A)  cyclins 
B)  Cdks 
C)  MPF 
D)  actin and tubulin 
E)  cohesins

Question 19

Use the data in Table 12.1 to answer the following questions.
The data were obtained from a study of the length of time spent in each phase of the cell cycle by cells of three eukaryotic organisms designated beta, delta, and gamma.
   
Table 12.1: Minutes Spent in Cell Cycle Phases
-Of the following, the best conclusion concerning the difference between the S phases for beta and gamma is that

Accepted Answer

A)  gamma contains more DNA than beta. 
B)  beta and gamma contain the same amount of DNA. 
C)  beta cells reproduce asexually. 
D)  gamma contains 48 times more DNA and RNA than beta. 
E)  beta is a plant cell and gamma is an animal cell. 
A)  gamma contains more DNA than beta. 
B)  beta and gamma contain the same amount of DNA. 
C)  beta cells reproduce asexually. 
D)  gamma contains 48 times more DNA and RNA than beta. 
E)  beta is a plant cell and gamma is an animal cell.

Question 20

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?

Accepted Answer

A)  G₀ 
B)  G₁ 
C)  S 
D)  G₂ 
E)  M 
A)  G₀ 
B)  G₁ 
C)  S 
D)  G₂ 
E)  M

Exam 12: The Cell Cycle

All cell cycle checkpoints are similar in which way?

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?

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?

What explains anchorage dependence of animal cells in vitro or in vivo?

The MPF protein complex turns itself off by

The following questions are based on Figure 12.3. Figure 12.3 -Which number represents DNA synthesis?

For anaphase to begin, which of the following must occur?

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?

Which of the following describe(s)cyclin-dependent kinase (Cdk)?

Why do neurons and some other specialized cells divide infrequently?

Density-dependent inhibition is explained by which of the following?

At the M phase checkpoint, the complex allows for what to occur?

The cyclin component of MPF is destroyed toward the end of which phase?

Vinblastine is a standard chemotherapeutic drug used to treat cancer. Because it interferes with the assembly of microtubules, its effectiveness must be related to

The drug cytochalasin B blocks the function of actin. Which of the following aspects of the cell cycle would be most disrupted by cytochalasin B?

Which of the following proteins are involved in binary fission as well as eukaryotic mitotic division?

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?

Introduction: Themes in the Study of Life

The Chemical Context of Life

Water and Life

Carbon and the Molecular Diversity of Life

The Structure and Function of Large Biological Molecules

A Tour of the Cell

Membrane Structure and Function

An Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

Cell Communication

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

From Gene to Protein

Regulation of Gene Expression

Viruses

Biotechnology

Genomes and Their Evolution

Descent with Modification: A Darwinian View of Life

The Evolution of Populations

The Origin of Species

The History of Life on Earth

Phylogeny and the Tree of Life

Bacteria and Archaea

Protists

Plant Diversity I: How Plants Colonized Land

Plant Diversity II: The Evolution of Seed Plants

Fungi

An Overview of Animal Diversity

An Introduction to Invertebrates

The Origin and Evolution of Vertebrates

Plant Structure, Growth, and Development

Resource Acquisition and Transport in Vascular Plants

Soil and Plant Nutrition

Angiosperm Reproduction and Biotechnology

Plant Responses to Internal and External Signals

Basic Principles of Animal Form and Function

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Osmoregulation and Excretion

Hormones and the Endocrine System

Animal Reproduction

Animal Development

Neurons, Synapses, and Signaling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behavior

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems and Restoration Ecology

Conservation Biology and Global Change

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