Question 1

Why do neurons and some other specialised 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 2

Scientists isolate cells in various phases of the cell cycle. They isolate a group of cells that have 1½ times more DNA than G1 phase cells. What is the most likely part of the cell cycle from which these cells were isolated?

Accepted Answer

A)  between the G1 and S phases in the cell cycle 
B)  in the G2 phase of the cell cycle 
C)  in the M phase of the cell cycle 
D)  in the S phase of the cell cycle 
A)  between the G1 and S phases in the cell cycle 
B)  in the G2 phase of the cell cycle 
C)  in the M phase of the cell cycle 
D)  in the S phase of the cell cycle

Question 3

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 4

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 5

The decline of MPF activity at the end of mitosis is due to

Accepted Answer

A)  the destruction of the protein kinase Cdk. 
B)  decreased synthesis of Cdk. 
C)  the degradation of cyclin. 
D)  the accumulation of cyclin. 
A)  the destruction of the protein kinase Cdk. 
B)  decreased synthesis of Cdk. 
C)  the degradation of cyclin. 
D)  the accumulation of cyclin.

Question 6

In a diploid cell with 5 chromosome pairs (2n = 10), how many centromeres will be found in a nucleus at G2 of the cell division cycle?

Accepted Answer

A)  5 
B)  10 
C)  20 
D)  40 
A)  5 
B)  10 
C)  20 
D)  40

Question 7

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 8

The beginning of anaphase is indicated by which of the following processes?

Accepted Answer

A)  Loss of kinetochores from the chromatids. 
B)  Attachment of sister chromatids to each other by cohesin. 
C)  Enzymatic cleavage of cohesin. 
D)  Disappearance of the nuclear membrane. 
A)  Loss of kinetochores from the chromatids. 
B)  Attachment of sister chromatids to each other by cohesin. 
C)  Enzymatic cleavage of cohesin. 
D)  Disappearance of the nuclear membrane.

Question 9

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 10

Several organisms, primarily protists, have what are called intermediate mitotic organisation. 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 11

For a chemotherapeutic drug to be useful for treating cancer cells, which of the following characteristics is most desirable?

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 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 rapidly dividing cells.

Question 12

Which of the following events occurs during interphase of the cell cycle?

Accepted Answer

A)  condensation of the chromosomes 
B)  separation of the spindle poles 
C)  spindle formation 
D)  replication of the DNA 
A)  condensation of the chromosomes 
B)  separation of the spindle poles 
C)  spindle formation 
D)  replication of the DNA

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

Motor proteins require which of the following structures or molecules to function in the movement of chromosomes toward the poles of the mitotic spindle?

Accepted Answer

A)  intact centromeres 
B)  a microtubule-organising centre 
C)  ATP as an energy source 
D)  intact cohesin 
A)  intact centromeres 
B)  a microtubule-organising centre 
C)  ATP as an energy source 
D)  intact cohesin

Question 15

If there are 40 centromeres in a cell at anaphase of mitosis, how many chromosomes will be found in each daughter cell following cytokinesis?

Accepted Answer

A)  10 
B)  20 
C)  40 
D)  80 
A)  10 
B)  20 
C)  40 
D)  80

Question 16

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 17

Which of the following does not occur during mitosis?

Accepted Answer

A)  condensation of the chromosomes 
B)  replication of the DNA 
C)  separation of sister chromatids 
D)  spindle formation 
A)  condensation of the chromosomes 
B)  replication of the DNA 
C)  separation of sister chromatids 
D)  spindle formation

Question 18

What is the name of the microtubule-organising centre 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 19

Movement of the chromosomes during anaphase would be most affected by a drug that prevents which of the following events in mitosis and cell division?

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 20

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

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

Exam 12: The Cell Cycle

Why do neurons and some other specialised cells divide infrequently?

Scientists isolate cells in various phases of the cell cycle. They isolate a group of cells that have 1½ times more DNA than G1 phase cells. What is the most likely part of the cell cycle from which these cells were isolated?

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

In the figure, MPF reaches its highest concentration during this stage.

The decline of MPF activity at the end of mitosis is due to

In a diploid cell with 5 chromosome pairs (2n = 10), how many centromeres will be found in a nucleus at G2 of the cell division 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

The beginning of anaphase is indicated by which of the following processes?

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?

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

For a chemotherapeutic drug to be useful for treating cancer cells, which of the following characteristics is most desirable?

Which of the following events occurs during interphase of the cell cycle?

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

Motor proteins require which of the following structures or molecules to function in the movement of chromosomes toward the poles of the mitotic spindle?

If there are 40 centromeres in a cell at anaphase of mitosis, how many chromosomes will be found in each daughter cell following cytokinesis?

A cleavage furrow is ________.

Which of the following does not occur during mitosis?

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

Movement of the chromosomes during anaphase would be most affected by a drug that prevents which of the following events in mitosis and cell division?

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

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 Colonised Land

Plant Diversity Ii: the Evolution of Seed Plants

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An Overview of Animal Diversity

An Introduction to Invertebrates

The Origin and Evolution of Vertebrates

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Basic Principles of Animal Form and Function

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