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

Which of the following statements best describes cells in culture that do not exhibit either density-dependent inhibition or anchorage dependence?

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 3

The drug cytochalasin B blocks the polymerization of actin microfilaments. Which of the following events of the cell cycle in animal cells would be most directly 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 4

Which of the following statements best describes density-dependent inhibition?

Accepted Answer

A)  As cells become more numerous, they begin to squeeze against each other, restricting their size. 
B)  As cells become more numerous, the cell surface proteins of one cell contact the adjoining cells, and they signal each other to 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, the level of waste products increases, which slows metabolism and inhibits growth. 
A)  As cells become more numerous, they begin to squeeze against each other, restricting their size. 
B)  As cells become more numerous, the cell surface proteins of one cell contact the adjoining cells, and they signal each other to 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, the level of waste products increases, which slows metabolism and inhibits growth.

Question 5

Exposure of zebrafish nuclei to cytosol isolated from eggs at metaphase of mitosis resulted in phosphorylation of NEP55 and L68 proteins by cyclin-dependent kinase 2. NEP55 is a protein of the inner nuclear membrane, and L68 is a protein of the nuclear lamina. What is the most likely role of phosphorylation of these proteins in the process of mitosis?

Accepted Answer

A)  They enable the attachment of spindle microtubules to kinetochores. 
B)  They are involved in chromosome condensation. 
C)  They are involved in the disassembly of the nuclear envelope. 
D)  They are involved in migration of centrosomes to opposite sides of the nucleus. 
A)  They enable the attachment of spindle microtubules to kinetochores. 
B)  They are involved in chromosome condensation. 
C)  They are involved in the disassembly of the nuclear envelope. 
D)  They are involved in migration of centrosomes to opposite sides of the nucleus.

Question 6

Which of the following events would be most likely to produce cells with several nuclei?

Accepted Answer

A)  repeated cytokinesis without mitosis 
B)  repeated mitosis with simultaneous cytokinesis 
C)  repeated mitosis without cytokinesis 
D)  multiple S phases without mitosis 
A)  repeated cytokinesis without mitosis 
B)  repeated mitosis with simultaneous cytokinesis 
C)  repeated mitosis without cytokinesis 
D)  multiple S phases without mitosis

Question 7

After DNA replication, each duplicated chromosome consists of two of which of the following structures?

Accepted Answer

A)  daughter chromosomes 
B)  daughter nucleosomes 
C)  sister chromatids 
D)  sister chromatins 
A)  daughter chromosomes 
B)  daughter nucleosomes 
C)  sister chromatids 
D)  sister chromatins

Question 8

If all chromosomes are not attached to the mitotic spindle at the M phase checkpoint, the cells would most likely be arrested at which of the following points in the cell division cycle or mitosis?

Accepted Answer

A)  telophase 
B)  prophase 
C)  G2 
D)  metaphase 
A)  telophase 
B)  prophase 
C)  G2 
D)  metaphase

Question 9

Which of the following properties is associated with a cyclin-dependent kinase (Cdk)?

Accepted Answer

A)  A Cdk is inactive, or "turned off," in the presence of a cyclin. 
B)  The number of Cdk molecules increases during the S and G2 phases and decrease during M. 
C)  A Cdk is an enzyme that catalyzes the attachment of kinetochores to microtubules. 
D)  A Cdk is an enzyme that attaches phosphate groups to other proteins. 
A)  A Cdk is inactive, or "turned off," in the presence of a cyclin. 
B)  The number of Cdk molecules increases during the S and G2 phases and decrease during M. 
C)  A Cdk is an enzyme that catalyzes the attachment of kinetochores to microtubules. 
D)  A Cdk is an enzyme that attaches phosphate groups to other proteins.

Question 10

Amount of DNA per nucleus over the cell division cycle.
Which numbered regions of the accompanying figure represent the DNA content associated with cells at metaphase?

Accepted Answer

A)  II and IV 
B)  II only 
C)  III only 
D)  IV only 
A)  II and IV 
B)  II only 
C)  III only 
D)  IV only

Question 11

Progression beyond the G2 checkpoint into mitosis is triggered by which of the following molecules?

Accepted Answer

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

Question 12

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 13

Which of the following characteristics would be most important for a chemotherapeutic drug designed to treat cancer cells?

Accepted Answer

A)  It is safe enough to prevent all apoptosis. 
B)  It does not interfere with metabolically active cells. 
C)  It specifically inhibits cells entering G0. 
D)  It specifically inhibits the cell division cycle in rapidly dividing cells. 
A)  It is safe enough to prevent all apoptosis. 
B)  It does not interfere with metabolically active cells. 
C)  It specifically inhibits cells entering G0. 
D)  It specifically inhibits the cell division cycle in rapidly dividing cells.

Question 14

Which of the following pairs of molecules make up 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

Question 15

Movement of the chromosomes during anaphase would be most directly affected by a drug that prevents which of the following events?

Accepted Answer

A)  nuclear envelope breakdown 
B)  elongation of microtubules 
C)  shortening of microtubules 
D)  formation of a cleavage furrow 
A)  nuclear envelope breakdown 
B)  elongation of microtubules 
C)  shortening of microtubules 
D)  formation of a cleavage furrow

Question 16

Which of the following structures or molecules is required in order for motor proteins to facilitate movement of chromosomes toward the poles in mitosis?

Accepted Answer

A)  intact centromeres 
B)  actin microfilaments 
C)  ATP as an energy source 
D)  intact cohesin 
A)  intact centromeres 
B)  actin microfilaments 
C)  ATP as an energy source 
D)  intact cohesin

Question 17

In a diploid cell with four chromosome pairs (2n = 8), how many centromeres will be found in a nucleus at G2 of the cell division cycle?

Accepted Answer

A)  4 
B)  8 
C)  16 
D)  32 
A)  4 
B)  8 
C)  16 
D)  32

Question 18

One type of eukaryotic cell (line 1) spends 24 minutes in S phase and another type of cell (line 2) spends 48 minutes in S phase. Which of the following statements is the best explanation for the difference in time spent in S phase by cell lines 1 and 2?   Amount of DNA per nucleus over the cell division cycle.

Accepted Answer

A)  Line 2 contains more DNA than line 1. 
B)  Lines 1 and 2 contain the same amount of DNA. 
C)  Line 1 cells reproduce by binary fission and line 2 cells reproduce by mitosis and cytokinesis. 
D)  Line 2 has plant cells and line 1 has animal cells. 
A)  Line 2 contains more DNA than line 1. 
B)  Lines 1 and 2 contain the same amount of DNA. 
C)  Line 1 cells reproduce by binary fission and line 2 cells reproduce by mitosis and cytokinesis. 
D)  Line 2 has plant cells and line 1 has animal cells.

Question 19

FtsZ is a bacterial protein that forms a contractile ring involved in binary fission. Its function is analogous to which of the following structures in eukaryotic cells?

Accepted Answer

A)  the cleavage furrow of eukaryotic animal cells 
B)  the cell plate of eukaryotic plant cells 
C)  the mitotic spindle of eukaryotic cells 
D)  the microtubule-organizing center of eukaryotic cells 
A)  the cleavage furrow of eukaryotic animal cells 
B)  the cell plate of eukaryotic plant cells 
C)  the mitotic spindle of eukaryotic cells 
D)  the microtubule-organizing center of eukaryotic cells

Question 20

Amount of DNA per nucleus over the cell division cycle.
G1 is represented by which numbered part(s) of the cell division cycle in the accompanying figure?

Accepted Answer

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

Exam 12: Mitosis

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

Which of the following statements best describes cells in culture that do not exhibit either density-dependent inhibition or anchorage dependence?

The drug cytochalasin B blocks the polymerization of actin microfilaments. Which of the following events of the cell cycle in animal cells would be most directly disrupted by cytochalasin B?

Which of the following statements best describes density-dependent inhibition?

Which of the following events would be most likely to produce cells with several nuclei?

After DNA replication, each duplicated chromosome consists of two of which of the following structures?

If all chromosomes are not attached to the mitotic spindle at the M phase checkpoint, the cells would most likely be arrested at which of the following points in the cell division cycle or mitosis?

Which of the following properties is associated with a cyclin-dependent kinase (Cdk)?

Amount of DNA per nucleus over the cell division cycle. Which numbered regions of the accompanying figure represent the DNA content associated with cells at metaphase?

Progression beyond the G2 checkpoint into mitosis is triggered by which of the following molecules?

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?

Which of the following characteristics would be most important for a chemotherapeutic drug designed to treat cancer cells?

Which of the following pairs of molecules make up an active MPF?

Movement of the chromosomes during anaphase would be most directly affected by a drug that prevents which of the following events?

Which of the following structures or molecules is required in order for motor proteins to facilitate movement of chromosomes toward the poles in mitosis?

In a diploid cell with four chromosome pairs (2n = 8), how many centromeres will be found in a nucleus at G2 of the cell division cycle?

FtsZ is a bacterial protein that forms a contractile ring involved in binary fission. Its function is analogous to which of the following structures in eukaryotic cells?

Amount of DNA per nucleus over the cell division cycle. G1 is represented by which numbered part(s) of the cell division cycle in the accompanying figure?

Biology and Its Themes

Atoms and Molecules

The Chemistry of Water

Carbon: the Basis of Molecular Diversity

Biological Macromolecules and Lipids

Energy and Life

Cell Structure and Function

Cell Membranes

Cellular Signaling

Cell Respiration

Photosynthetic Processes

Sexual Life Cycles and Meiosis

Mendelian Genetics

Linkage and Chromosomes

Nucleic Acids and Inheritance

Expression of Genes

Control of Gene Expression

Dna Technology

The Evolution of Genomes

How Evolution Works

Phylogenetic Reconstruction

Microevolution

Species and Speciation

Macroevolution

Introduction to Viruses

Prokaryotes

The Origin and Evolution of Eukaryotes

Nonvascular and Seedless Vascular Plants

Seed Plants

Introduction to Fungi

An Introduction to Animal Diversity

Invertebrates

Vertebrates

Plant Structure and Growth

Transport in Vascular Plants

Plant Nutrition

Reproduction of Flowering Plants

Plant Signals and Behavior

The Animal Body

Chemical Signals in Animals

Animal Digestive Systems

Animal Transport Systems

Animal Excretory Systems

Animal Reproductive Systems

Development in Animals

Animal Defenses Against Infection

Electrical Signals in Animals

Neural Regulation in Animals

Sensation and Movement in Animals

An Overview of Ecology

Behavioral Ecology

Populations and Life History Traits

Biodiversity and Communities

Energy Flow and Chemical Cycling in Ecosystems

Conservation and Global Ecology

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