Question 1

In the cells of some organisms, mitosis occurs without cytokinesis. This will result in

Accepted Answer

A)  cells with more than one nucleus. 
B)  cells that are unusually small. 
C)  cells lacking nuclei. 
D)  cell cycles lacking an S phase. 
A)  cells with more than one nucleus. 
B)  cells that are unusually small. 
C)  cells lacking nuclei. 
D)  cell cycles lacking an S phase.

Question 2

Use the figure to answer the question below.
 
In the figure, G₁ is represented by which numbered part(s) of the cycle?

Accepted Answer

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

Question 3

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 4

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 5

How is plant cell cytokinesis different from animal cell cytokinesis?

Accepted Answer

A)  The contractile filaments found in plant cells are structures composed of carbohydrates; the cleavage furrow in animal cells is composed of contractile proteins. 
B)  Plant cells deposit vesicles containing cell wall building blocks on the metaphase plate; animal cells form a cleavage furrow. 
C)  The structural proteins of plant cells separate the two cells; in animal cells, a cell membrane separates the two daughter cells. 
D)  Plant cells divide after metaphase but before anaphase; animal cells divide after anaphase. 
A)  The contractile filaments found in plant cells are structures composed of carbohydrates; the cleavage furrow in animal cells is composed of contractile proteins. 
B)  Plant cells deposit vesicles containing cell wall building blocks on the metaphase plate; animal cells form a cleavage furrow. 
C)  The structural proteins of plant cells separate the two cells; in animal cells, a cell membrane separates the two daughter cells. 
D)  Plant cells divide after metaphase but before anaphase; animal cells divide after anaphase.

Question 6

In the cells of many eukaryotic species, the nuclear envelope has to disappear to permit which of the following events in the cell cycle?

Accepted Answer

A)  DNA synthesis 
B)  attachment of microtubules to kinetochores 
C)  separation of the centrosomes 
D)  condensation of the chromosomes 
A)  DNA synthesis 
B)  attachment of microtubules to kinetochores 
C)  separation of the centrosomes 
D)  condensation of the chromosomes

Question 7

Certain unicellular eukaryotes, including diatoms and some yeasts, have mechanisms of nuclear division that may resemble intermediate steps in the evolution of mitosis. Which of the following is a characteristic feature of nuclear division in these organisms?

Accepted Answer

A)  They reproduce by binary fission in their early stages of development and by mitosis when they are mature. 
B)  They have circular chromosomes that are segregated by a mitotic spindle. 
C)  Chromosomes are segregated by a mitotic spindle, but the nuclear envelope remains intact during division. 
D)  Chromosomes are segregated by attachment to the plasma membrane. 
A)  They reproduce by binary fission in their early stages of development and by mitosis when they are mature. 
B)  They have circular chromosomes that are segregated by a mitotic spindle. 
C)  Chromosomes are segregated by a mitotic spindle, but the nuclear envelope remains intact during division. 
D)  Chromosomes are segregated by attachment to the plasma membrane.

Question 8

During which phase of mitosis do the chromatids become chromosomes?

Accepted Answer

A)  telophase 
B)  anaphase 
C)  prophase 
D)  metaphase 
A)  telophase 
B)  anaphase 
C)  prophase 
D)  metaphase

Question 9

Besides the ability of some cancer cells to over proliferate, which of the following situations might logically result in a tumor?

Accepted Answer

A)  changes in the order of cell cycle stages 
B)  lack of appropriate cell death 
C)  inability to form spindles 
D)  failure of cells to enter S phase 
A)  changes in the order of cell cycle stages 
B)  lack of appropriate cell death 
C)  inability to form spindles 
D)  failure of cells to enter S phase

Question 10

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 at prometaphase of mitosis?

Accepted Answer

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

Question 11

In what way do kinetochore microtubules facilitate the process of splitting the centromeres?

Accepted Answer

A)  They use motor proteins to hydrolyze the centromere at specific arginine residues. 
B)  They create tension by pulling toward opposite poles. 
C)  They slide past each other like actin microfilaments. 
D)  They phosphorylate the centromere, thereby changing its conformation. 
A)  They use motor proteins to hydrolyze the centromere at specific arginine residues. 
B)  They create tension by pulling toward opposite poles. 
C)  They slide past each other like actin microfilaments. 
D)  They phosphorylate the centromere, thereby changing its conformation.

Question 12

Cells from advanced malignant tumors often have very abnormal chromosomes and an abnormal number of chromosomes. What might explain the association between malignant tumors and chromosomal abnormalities?

Accepted Answer

A)  Cancer cells are no longer density-dependent. 
B)  Cancer cells are no longer anchorage-dependent. 
C)  Cell cycle checkpoints are not in place to stop cells with chromosome abnormalities. 
D)  Transformation introduces new chromosomes into cells. 
A)  Cancer cells are no longer density-dependent. 
B)  Cancer cells are no longer anchorage-dependent. 
C)  Cell cycle checkpoints are not in place to stop cells with chromosome abnormalities. 
D)  Transformation introduces new chromosomes into cells.

Question 13

Which of the following molecules triggers the cell's passage past the G₂ checkpoint into mitosis?

Accepted Answer

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

Question 14

Use the data in the accompanying table to answer the question.
Minutes Spent in Cell Cycle Phases
 
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 G₀ phase. 
D)  Delta cells divide in the G₁ phase. 
A)  Delta cells contain no DNA. 
B)  Delta cells contain no RNA. 
C)  Delta cells are in the G₀ phase. 
D)  Delta cells divide in the G₁ phase.

Question 15

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 16

Use the data in the accompanying table to answer the question.
Minutes Spent in Cell Cycle Phases
 
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.
Which of the statements is the best explanation for the difference between time spent in S phase by beta and gamma?

Accepted Answer

A)  Gamma contains more DNA than beta. 
B)  Beta and gamma contain the same amount of DNA. 
C)  Beta cells reproduce by binary fission and gamma cells reproduce by mitosis and cytokinesis. 
D)  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 by binary fission and gamma cells reproduce by mitosis and cytokinesis. 
D)  Beta is a plant cell and gamma is an animal cell.

Question 17

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 18

Early observations of a cultured cell line indicated that the cells did not exhibit either density-dependent inhibition or anchorage dependence. What do these observations suggest about this cell line?

Accepted Answer

A)  The cells are unable to form spindle microtubules. 
B)  The cells follow an altered series of cell cycle phases. 
C)  The cells show characteristics of tumors. 
D)  The cells have nonfunctional MPF. 
A)  The cells are unable to form spindle microtubules. 
B)  The cells follow an altered series of cell cycle phases. 
C)  The cells show characteristics of tumors. 
D)  The cells have nonfunctional MPF.

Question 19

Certain cell types normally have several nuclei per cell. How could such multinucleated cells be explained?

Accepted Answer

A)  The cell underwent repeated cytokinesis but no mitosis. 
B)  The cell underwent repeated mitosis with simultaneous cytokinesis. 
C)  The cell underwent repeated mitosis, but cytokinesis did not occur. 
D)  The cell had multiple S phases before it entered mitosis. 
A)  The cell underwent repeated cytokinesis but no mitosis. 
B)  The cell underwent repeated mitosis with simultaneous cytokinesis. 
C)  The cell underwent repeated mitosis, but cytokinesis did not occur. 
D)  The cell had multiple S phases before it entered mitosis.

Question 20

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)  an animal cell in anaphase of mitosis 
C)  a plant cell in the process of cytokinesis 
D)  a plant cell in metaphase of mitosis 
A)  an animal cell in the process of cytokinesis 
B)  an animal cell in anaphase of mitosis 
C)  a plant cell in the process of cytokinesis 
D)  a plant cell in metaphase of mitosis

Exam 12: The Cell Cycle

In the cells of some organisms, mitosis occurs without cytokinesis. This will result in

Use the figure to answer the question below. In the figure, G₁ is represented by which numbered part(s) of the cycle?

Why do neurons and some other specialized cells divide infrequently?

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

How is plant cell cytokinesis different from animal cell cytokinesis?

In the cells of many eukaryotic species, the nuclear envelope has to disappear to permit which of the following events in the cell cycle?

Certain unicellular eukaryotes, including diatoms and some yeasts, have mechanisms of nuclear division that may resemble intermediate steps in the evolution of mitosis. Which of the following is a characteristic feature of nuclear division in these organisms?

During which phase of mitosis do the chromatids become chromosomes?

Besides the ability of some cancer cells to over proliferate, which of the following situations might logically result in a tumor?

In what way do kinetochore microtubules facilitate the process of splitting the centromeres?

Cells from advanced malignant tumors often have very abnormal chromosomes and an abnormal number of chromosomes. What might explain the association between malignant tumors and chromosomal abnormalities?

Which of the following molecules triggers the cell's passage past the G₂ checkpoint into mitosis?

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?

Eukaryotic chromosomes are composed of which of the following macromolecules?

Early observations of a cultured cell line indicated that the cells did not exhibit either density-dependent inhibition or anchorage dependence. What do these observations suggest about this cell line?

Certain cell types normally have several nuclei per cell. How could such multinucleated cells be explained?

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 ________.

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

Filters