Question 1

Which of the following statements is FALSE with respect to both bacterial binary fission and eukaryotic mitotic cell division?

Accepted Answer

A)  The nuclear envelope must disintegrate before the spindle apparatus can move the chromosomes. 
B)  DNA must be replicated prior to division. 
C)  Daughter cells must contain the same hereditary material as one another and the parent cell. 
D)  Cytoplasmic materials must be distributed to each of the daughter cells. 
A)  The nuclear envelope must disintegrate before the spindle apparatus can move the chromosomes. 
B)  DNA must be replicated prior to division. 
C)  Daughter cells must contain the same hereditary material as one another and the parent cell. 
D)  Cytoplasmic materials must be distributed to each of the daughter cells. A

Question 2

The M- phase checkpoint is designed to make sure all chromosomes are attached to the mitotic spindle. If this fails to happen, in which stage of mitosis would the cells be most likely to arrest?

Accepted Answer

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

Question 3

A cyclin

Accepted Answer

A)  activates a Cdk molecule when its concentration is decreased. 
B)  is present in similar concentrations throughout the cell cycle. 
C)  activates a Cdk molecule when it is in sufficient concentration. 
D)  decreases in concentration when M phase-promoting factor MPF) activity increases. 
E)  is activated by binding to microtubules. 
A)  activates a Cdk molecule when its concentration is decreased. 
B)  is present in similar concentrations throughout the cell cycle. 
C)  activates a Cdk molecule when it is in sufficient concentration. 
D)  decreases in concentration when M phase-promoting factor MPF) activity increases. 
E)  is activated by binding to microtubules. C

Question 4

The first gap in the cell cycle G1) corresponds to

Accepted Answer

A)  the beginning of mitosis. 
B)  the phase in which DNA is being replicated. 
C)  normal growth and functioning. 
D)  the phase between DNA replication and the M phase. 
A)  the beginning of mitosis. 
B)  the phase in which DNA is being replicated. 
C)  normal growth and functioning. 
D)  the phase between DNA replication and the M phase.

Question 5

In a culture of cells, it is observed that the cell cycle has arrested stopped) during the G1 phase. The reason for this could be that

Accepted Answer

A)  not all components needed for DNA replication are present. 
B)  not all components needed for mitosis are present. 
C)  not all chromosomes have been replicated. 
D)  not all chromosomes are attached to mitotic spindles. 
A)  not all components needed for DNA replication are present. 
B)  not all components needed for mitosis are present. 
C)  not all chromosomes have been replicated. 
D)  not all chromosomes are attached to mitotic spindles.

Question 6

Metaphase occurs prior to the splitting of centromeres. It is characterized by

Accepted Answer

A)  aligning of chromosomes on the equator. 
B)  disassembly of the nuclear envelope. 
C)  duplication of centrioles. 
D)  cytokinesis. 
A)  aligning of chromosomes on the equator. 
B)  disassembly of the nuclear envelope. 
C)  duplication of centrioles. 
D)  cytokinesis.

Question 7

Cancer- causing mutated tumour suppressor genes result from which of the following?

Accepted Answer

A)  mutations in genes encoding proteins that normally inhibit progression through the cell cycle 
B)  mutations that cause overexpression of genes encoding proteins that normally stimulate progression through the cell cycle 
C)  cell- contact inhibition 
D)  programmed cell death 
A)  mutations in genes encoding proteins that normally inhibit progression through the cell cycle 
B)  mutations that cause overexpression of genes encoding proteins that normally stimulate progression through the cell cycle 
C)  cell- contact inhibition 
D)  programmed cell death

Question 8

Once researchers understood that chromosomes are moved by the spindle microtubules, the next question they wanted to answer is how the microtubules function to bring about this process. They used fluorescent labels to make the chromosomes and the microtubular structures fluoresce. When anaphase began centromeres split), they photobleached a section of microtubules. As chromosomes moved toward the poles of the daughter cells, the photobleached sections of the microtubules remained stationary. This result suggests that

Accepted Answer

A)  the microtubules elongate and shorten at the centrosome end. 
B)  the microtubules elongate and shorten at their kinetochore end. 
C)  the microtubules are of constant length; centrosomes move farther apart to separate chromosomes. 
D)  the microtubules overlap and slide with respect to each other, effectively shortening the microtubules without depolymerizing the actual fiber. 
A)  the microtubules elongate and shorten at the centrosome end. 
B)  the microtubules elongate and shorten at their kinetochore end. 
C)  the microtubules are of constant length; centrosomes move farther apart to separate chromosomes. 
D)  the microtubules overlap and slide with respect to each other, effectively shortening the microtubules without depolymerizing the actual fiber.

Question 9

How is plant cell cytokinesis different from animal cell cytokinesis?

Accepted Answer

A)  Plant cells deposit vesicles containing cell- wall building blocks on the metaphase plate; animal cells form a cleavage furrow. 
B)  The cleavage furrow in animal cells is composed of protein contractile filaments; the contractile filaments found in plant cells are structures composed of carbohydrates. 
C)  Animal cells have centrosomes that are involved in this process, but plant cells have microtubular organizing centers that are not detectable during most of the cell cycle. 
D)  The structural carbohydrates of the plant cells separate the two cells, whereas in animal cells, a cell membrane separates the two daughter cells. 
A)  Plant cells deposit vesicles containing cell- wall building blocks on the metaphase plate; animal cells form a cleavage furrow. 
B)  The cleavage furrow in animal cells is composed of protein contractile filaments; the contractile filaments found in plant cells are structures composed of carbohydrates. 
C)  Animal cells have centrosomes that are involved in this process, but plant cells have microtubular organizing centers that are not detectable during most of the cell cycle. 
D)  The structural carbohydrates of the plant cells separate the two cells, whereas in animal cells, a cell membrane separates the two daughter cells.

Question 10

How might spindle microtubules assist in the process of splitting centromeres?

Accepted Answer

A)  coding for enzymes involved in the process 
B)  creating tension by pulling toward opposite poles 
C)  the use of motor proteins to split the centromere at specific arginine residues 
D)  phosphorylating the centromere, which changes its conformation 
A)  coding for enzymes involved in the process 
B)  creating tension by pulling toward opposite poles 
C)  the use of motor proteins to split the centromere at specific arginine residues 
D)  phosphorylating the centromere, which changes its conformation

Question 11

Some cells have several nuclei per cell. How might such multinucleated cells arise?

Accepted Answer

A)  repeated mitosis with concomitant cytokinesis 
B)  multiple S phases before the entry of a cell into mitosis 
C)  repeated mitosis without cytokinesis 
D)  repeated cytokinesis with no mitosis 
A)  repeated mitosis with concomitant cytokinesis 
B)  multiple S phases before the entry of a cell into mitosis 
C)  repeated mitosis without cytokinesis 
D)  repeated cytokinesis with no mitosis

Question 12

Which of the following is NOT involved in the regulation of the eukaryotic cell cycle?

Accepted Answer

A)  ribosomes 
B)  cyclins 
C)  hormones 
D)  cyclin- dependent kinases CDKs) 
E)  p53 
A)  ribosomes 
B)  cyclins 
C)  hormones 
D)  cyclin- dependent kinases CDKs) 
E)  p53

Question 13

The mitotic spindle is a microtubular structure that is involved in

Accepted Answer

A)  separation of sister chromatids. 
B)  disassembly of the nucleolus. 
C)  triggering the compaction and condensation of chromosomes. 
D)  splitting of the cell cytokinesis) following mitosis. 
A)  separation of sister chromatids. 
B)  disassembly of the nucleolus. 
C)  triggering the compaction and condensation of chromosomes. 
D)  splitting of the cell cytokinesis) following mitosis.

Question 14

Which of the following is not an effect of mitosis- promoting factor MPF) involved in moving a cell into M phase?

Accepted Answer

A)  phosphorylation of lamins, initiating breakdown of the nuclear membrane 
B)  phosphorylation of an enzyme that breaks down the cyclin molecule 
C)  phosphorylation of microtubule associated proteins, triggering the formation of the mitotic spindle 
D)  degradation of cyclin- dependent kinase 
A)  phosphorylation of lamins, initiating breakdown of the nuclear membrane 
B)  phosphorylation of an enzyme that breaks down the cyclin molecule 
C)  phosphorylation of microtubule associated proteins, triggering the formation of the mitotic spindle 
D)  degradation of cyclin- dependent kinase

Question 15

Scientists isolate cells in various phases of the cell cycle. They find a group of cells that have 1½ times more DNA than G1 phase cells. The cells of this group are in

Accepted Answer

A)  the process of cytokinesis. 
B)  S phase. 
C)  M phase. 
D)  the G2 phase of the cell cycle. 
A)  the process of cytokinesis. 
B)  S phase. 
C)  M phase. 
D)  the G2 phase of the cell cycle.

Question 16

For cells to divide more rapidly, increased production would likely be required of each of the following proteins EXCEPT

Accepted Answer

A)  activated MPF. 
B)  p53. 
C)  cyclins. 
D)  PDGF. 
A)  activated MPF. 
B)  p53. 
C)  cyclins. 
D)  PDGF.

Question 17

Exposure of zebrafish nuclei to meiotic cytosol 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 assist in the movement of the centrosomes to opposite sides of the nucleus. 
B)  They enable the attachment of the spindle microtubules to kinetochore regions of the centromere. 
C)  They are involved in the disassembly and dispersal of the nucleolus. 
D)  They are involved in the disassembly of the nuclear envelope. 
A)  They assist in the movement of the centrosomes to opposite sides of the nucleus. 
B)  They enable the attachment of the spindle microtubules to kinetochore regions of the centromere. 
C)  They are involved in the disassembly and dispersal of the nucleolus. 
D)  They are involved in the disassembly of the nuclear envelope.

Question 18

Myosin is a motor protein involved in animal cell cytokinesis. It binds to ATP or ADP, causing the myosin to move with respect to actin. What is the effect of the interaction between myosin and actin?

Accepted Answer

A)  Excess cytoplasm is removed. 
B)  Vesicles containing plasma membrane constituents are transported to the metaphase plate, where cytokinesis takes place. 
C)  The cleavage furrow deepens. 
D)  It triggers the reformation of the daughter nuclei. 
A)  Excess cytoplasm is removed. 
B)  Vesicles containing plasma membrane constituents are transported to the metaphase plate, where cytokinesis takes place. 
C)  The cleavage furrow deepens. 
D)  It triggers the reformation of the daughter nuclei.

Question 19

Once a cell completes mitosis, molecular division triggers must be turned off. What happens to MPF during mitosis?

Accepted Answer

A)  Cyclin is degraded; the concentration of cyclin- dependent kinase remains unchanged, but without cyclin, MPF is not formed. 
B)  The cyclin- dependent kinases take on a function unrelated to mitosis. 
C)  It is completely degraded. 
D)  Cyclin- dependent kinase is degraded; cyclin concentration remains constant, but without cyclin- dependent kinase, MPF is not formed. 
A)  Cyclin is degraded; the concentration of cyclin- dependent kinase remains unchanged, but without cyclin, MPF is not formed. 
B)  The cyclin- dependent kinases take on a function unrelated to mitosis. 
C)  It is completely degraded. 
D)  Cyclin- dependent kinase is degraded; cyclin concentration remains constant, but without cyclin- dependent kinase, MPF is not formed.

Question 20

Mitosis is the process of chromosome separation. Cytoplasm is divided between the two daughter cells in a process known as

Accepted Answer

A)  karyokinesis. 
B)  G1 phase. 
C)  S phase. 
D)  cytokinesis. 
A)  karyokinesis. 
B)  G1 phase. 
C)  S phase. 
D)  cytokinesis.

Exam 12: The Cell Cycle

Which of the following statements is FALSE with respect to both bacterial binary fission and eukaryotic mitotic cell division?

The M- phase checkpoint is designed to make sure all chromosomes are attached to the mitotic spindle. If this fails to happen, in which stage of mitosis would the cells be most likely to arrest?

A cyclin

The first gap in the cell cycle G1) corresponds to

In a culture of cells, it is observed that the cell cycle has arrested stopped) during the G1 phase. The reason for this could be that

Metaphase occurs prior to the splitting of centromeres. It is characterized by

Cancer- causing mutated tumour suppressor genes result from which of the following?

How is plant cell cytokinesis different from animal cell cytokinesis?

How might spindle microtubules assist in the process of splitting centromeres?

Some cells have several nuclei per cell. How might such multinucleated cells arise?

Which of the following is NOT involved in the regulation of the eukaryotic cell cycle?

The mitotic spindle is a microtubular structure that is involved in

Which of the following is not an effect of mitosis- promoting factor MPF) involved in moving a cell into M phase?

Scientists isolate cells in various phases of the cell cycle. They find a group of cells that have 1½ times more DNA than G1 phase cells. The cells of this group are in

For cells to divide more rapidly, increased production would likely be required of each of the following proteins EXCEPT

Myosin is a motor protein involved in animal cell cytokinesis. It binds to ATP or ADP, causing the myosin to move with respect to actin. What is the effect of the interaction between myosin and actin?

Once a cell completes mitosis, molecular division triggers must be turned off. What happens to MPF during mitosis?

Mitosis is the process of chromosome separation. Cytoplasm is divided between the two daughter cells in a process known as

Biology and the Tree of Life

Water and Carbon: the Chemical Basis of Life

Protein Structure and Function

Nucleic Acids and the Rna World

An Introduction to Carbohydrates

Lipids, Membranes, and the First Cells

Inside the Cell

Energy and Enzymes

Cellular Respiration and Fermentation

Photosynthesis

Cellcell Interactions

Meiosis

Mendel and the Gene

Dna and the Gene: Synthesis and Repair

How Genes Work

Transcription, Rna Processing, and Translation

Control of Gene Expression in Bacteria

Control of Gene Expression in Eukaryotes

The Molecular Revolution: Biotechnology and Beyond

Gene Structure and Development

Evolution by Natural Selection

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Speciation

Phylogenies and the History of Life

Bacteria and Archaea

Protists

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An Introduction to Animals

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Water and Sugar Transport in Plants

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Water and Electrolyte Balance in Animals

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Chemical Signals in Animals

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The Immune System in Animals

An Introduction to Ecology

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The first gap in the cell cycle G₁) corresponds to

Scientists isolate cells in various phases of the cell cycle. They find a group of cells that have 1½ times more DNA than G₁phase cells. The cells of this group are in