Question 1

Through a microscope, you can see a cell plate beginning to develop across the middle of a cell and nuclei forming on either side of the cell plate. This cell is most likely

Accepted Answer

A)  an animal cell in the process of cytokinesis. 
B)  a plant cell in the process of cytokinesis. 
C)  a bacterial cell dividing. 
D)  a plant cell in metaphase. 
A)  an animal cell in the process of cytokinesis. 
B)  a plant cell in the process of cytokinesis. 
C)  a bacterial cell dividing. 
D)  a plant cell in metaphase.

Question 2

Which of the following molecules is a protein maintained at steady levels throughout the cell cycle that requires cyclin to become catalytically active?

Accepted Answer

A)  PDGF 
B)  MPF 
C)  cyclin 
D)  Cdk 
A)  PDGF 
B)  MPF 
C)  cyclin 
D)  Cdk

Question 3

A cleavage furrow is ________.

Accepted Answer

A)  a ring of vesicles forming a cell plate 
B)  the separation of divided prokaryotes 
C)  a groove in the plasma membrane between daughter nuclei 
D)  the space that is created between two chromatids during anaphase 
A)  a ring of vesicles forming a cell plate 
B)  the separation of divided prokaryotes 
C)  a groove in the plasma membrane between daughter nuclei 
D)  the space that is created between two chromatids during anaphase

Question 4

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. How many picograms of DNA would be found in a nucleus at prophase of mitosis?

Accepted Answer

A)  4 
B)  8 
C)  16 
D)  24 
A)  4 
B)  8 
C)  16 
D)  24

Question 5

Why do neurons and some other specialized cells divide infrequently?

Accepted Answer

A)  They no longer have active nuclei. 
B)  They have entered into G₀. 
C)  They can no longer degrade cyclins. 
D)  They no longer produce MPF. 
A)  They no longer have active nuclei. 
B)  They have entered into G₀. 
C)  They can no longer degrade cyclins. 
D)  They no longer produce MPF.

Question 6

Use the data in the accompanying table to answer the question.
Minutes Spent in Cell Cycle Phases
$$\begin{array} { | l | l | l | l | l | } 
\hline \text { Cell Type } & \mathbf { G } _ { \mathbf { 1 } } & \mathbf { s } & \mathbf { G } _ { 2 } & \mathbf { M } \
\hline \text { Beta } & 18 & 24 & 12 & 16 \
\hline \text { Delta } & 100 & 1 & 0 & 0 \
\hline \text { Gamma } & 18 & 48 & 14 & 20 \
\hline
\end{array}$$
The data in the table 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. What is the best explanation for the data associated with delta cells?

Accepted Answer

A)  Delta cells contain no DNA. 
B)  Delta cells contain no RNA. 
C)  Delta cells are in the G? phase. 
D)  Delta cells divide in the G? phase. 
A)  Delta cells contain no DNA. 
B)  Delta cells contain no RNA. 
C)  Delta cells are in the G? phase. 
D)  Delta cells divide in the G? phase.

Question 7

Nucleotides can be radiolabeled before they are incorporated into newly forming DNA and, therefore, can be assayed to track their incorporation. In a set of experiments, a student-faculty research team used labeled T nucleotides to study the incorporation of labeled nucleotides into a culture of lymphocytes. They found that the lymphocytes incorporated the labeled nucleotide at a significantly higher level after a pathogen was introduced into the culture. What might they conclude from this observation?

Accepted Answer

A)  The pathogen consumed radiolabeled nucleotides. 
B)  Infection causes lymphocytes to divide more rapidly. 
C)  Infection causes lymphocytes to increase in size. 
D)  Infection causes lymphocyte cultures to skip some parts of the cell cycle. 
A)  The pathogen consumed radiolabeled nucleotides. 
B)  Infection causes lymphocytes to divide more rapidly. 
C)  Infection causes lymphocytes to increase in size. 
D)  Infection causes lymphocyte cultures to skip some parts of the cell cycle.

Question 8

Use the figure to answer the question below.
 
In the figure, which number represents DNA synthesis?

Accepted Answer

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

Question 9

Use the figure to answer the question below.
 
In the figure, MPF reaches its highest concentration during this stage.

Accepted Answer

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

Question 10

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

Accepted Answer

A)  spindle formation 
B)  spindle attachment to kinetochores 
C)  movement of chromosomes to the poles during anaphase 
D)  cleavage furrow formation and cytokinesis 
A)  spindle formation 
B)  spindle attachment to kinetochores 
C)  movement of chromosomes to the poles during anaphase 
D)  cleavage furrow formation and cytokinesis

Question 11

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

Accepted Answer

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

Question 12

Several organisms, primarily protists, have what are called intermediate mitotic organization. What is the most probable hypothesis about these intermediate forms of cell division?

Accepted Answer

A)  They represent a form of cell reproduction that must have evolved completely separately from those of other organisms. 
B)  They rely on totally different proteins for the processes they undergo. 
C)  They may be more closely related to plant forms that also have unusual mitosis. 
D)  They show some but not all of the evolutionary steps toward complete mitosis. 
A)  They represent a form of cell reproduction that must have evolved completely separately from those of other organisms. 
B)  They rely on totally different proteins for the processes they undergo. 
C)  They may be more closely related to plant forms that also have unusual mitosis. 
D)  They show some but not all of the evolutionary steps toward complete mitosis.

Question 13

What is the name of the microtubule-organizing center found in animal cells as an identifiable structure present during all phases of the cell cycle?

Accepted Answer

A)  centriole 
B)  centrosome 
C)  centromere 
D)  kinetochore 
A)  centriole 
B)  centrosome 
C)  centromere 
D)  kinetochore

Question 14

One difference between cancer cells and normal cells is that cancer cells

Accepted Answer

A)  are unable to synthesize DNA. 
B)  are arrested at the S phase of the cell cycle. 
C)  continue to divide even when they are tightly packed together. 
D)  cannot function properly because they are affected by density-dependent inhibition. 
A)  are unable to synthesize DNA. 
B)  are arrested at the S phase of the cell cycle. 
C)  continue to divide even when they are tightly packed together. 
D)  cannot function properly because they are affected by density-dependent inhibition.

Question 15

At what stage of the cell cycle is the cyclin component of MPF destroyed?

Accepted Answer

A)  in late G₁ 
B)  at mid-S phase 
C)  in early G₂ 
D)  in late M 
A)  in late G₁ 
B)  at mid-S phase 
C)  in early G₂ 
D)  in late M

Question 16

Use the figure to answer the question below.
The unlettered circle at the top of the figure shows a diploid nucleus with four chromosomes that have not yet replicated. There are two pairs of homologous chromosomes, one long and the other short. One haploid set is black, and the other is gray. The circles labeled A to E show various combinations of these chromosomes.
 
What is the correct chromosomal condition for one daughter nucleus at telophase of mitosis?

Accepted Answer

A)  B 
B)  C 
C)  D 
D)  E 
A)  B 
B)  C 
C)  D 
D)  E

Question 17

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

Question 18

Eukaryotic chromosomes are composed of which of the following macromolecules?

Accepted Answer

A)  DNA and RNA 
B)  DNA only 
C)  DNA and proteins 
D)  DNA and phospholipids 
A)  DNA and RNA 
B)  DNA only 
C)  DNA and proteins 
D)  DNA and phospholipids

Question 19

Which of the following molecules is released by platelets in the vicinity of an injury?

Accepted Answer

A)  PDGF 
B)  MPF 
C)  cyclin 
D)  Cdk 
A)  PDGF 
B)  MPF 
C)  cyclin 
D)  Cdk

Question 20

What two components constitute an active MPF?

Accepted Answer

A)  a growth factor and mitotic factor 
B)  ATP synthetase and a protease 
C)  cyclin and tubulin 
D)  cyclin and a cyclin-dependent kinase 
A)  a growth factor and mitotic factor 
B)  ATP synthetase and a protease 
C)  cyclin and tubulin 
D)  cyclin and a cyclin-dependent kinase

Exam 12: The Cell Cycle

Through a microscope, you can see a cell plate beginning to develop across the middle of a cell and nuclei forming on either side of the cell plate. This cell is most likely

Which of the following molecules is a protein maintained at steady levels throughout the cell cycle that requires cyclin to become catalytically active?

A cleavage furrow is ________.

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. How many picograms of DNA would be found in a nucleus at prophase of mitosis?

Why do neurons and some other specialized cells divide infrequently?

Use the figure to answer the question below. In the figure, which number represents DNA synthesis?

Use the figure to answer the question below. In the figure, MPF reaches its highest concentration during this stage.

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

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

Several organisms, primarily protists, have what are called intermediate mitotic organization. What is the most probable hypothesis about these intermediate forms of cell division?

What is the name of the microtubule-organizing center found in animal cells as an identifiable structure present during all phases of the cell cycle?

One difference between cancer cells and normal cells is that cancer cells

At what stage of the cell cycle is the cyclin component of MPF destroyed?

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

Eukaryotic chromosomes are composed of which of the following macromolecules?

Which of the following molecules is released by platelets in the vicinity of an injury?

What two components constitute an active MPF?

Evolution, the Themes of Biology, and Scientific Inquiry

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

Gene Expression: From Gene to Protein

Regulation of Gene Expression

Viruses

DNA Tools and 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

Vascular 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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