Question 1

If cells in the process of dividing are subjected to colchicine, a drug that interferes with the formation of the spindle apparatus, at which stage will mitosis be arrested?

Accepted Answer

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

Question 2

Which of the following is true concerning cancer cells?

Accepted Answer

A) They do not exhibit density-dependent inhibition when growing in culture. 
B) When they stop dividing, they do so at random points in the cell cycle. 
C) They are not subject to cell cycle controls. 
D) When they stop dividing, they do so at random points in the cell cycle, and they are not subject to cell cycle controls. 
E) When they stop dividing, they do so at random points in the cell cycle; they are not subject to cell cycle controls; and they do not exhibit density-dependent inhibition when grown in culture. 
A) They do not exhibit density-dependent inhibition when growing in culture. 
B) When they stop dividing, they do so at random points in the cell cycle. 
C) They are not subject to cell cycle controls. 
D) When they stop dividing, they do so at random points in the cell cycle, and they are not subject to cell cycle controls. 
E) When they stop dividing, they do so at random points in the cell cycle; they are not subject to cell cycle controls; and they do not exhibit density-dependent inhibition when grown in culture.

Question 3

The following information applies to the questions below.
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 demonstrate that these species are not closely related to any of the other protists and may well be a different kingdom. 
C) They rely on totally different proteins for the processes they undergo. 
D) They may be more closely related to plant forms that also have unusual mitosis. 
E) 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 demonstrate that these species are not closely related to any of the other protists and may well be a different kingdom. 
C) They rely on totally different proteins for the processes they undergo. 
D) They may be more closely related to plant forms that also have unusual mitosis. 
E) They show some but not all of the evolutionary steps toward complete mitosis.

Question 4

What causes the decrease in the amount of cyclin at a specific point in the cell cycle?

Accepted Answer

A) an increase in production once the restriction point is passed 
B) the cascade of increased production once its protein is phosphorylated by Cdk 
C) the changing ratio of cytoplasm to genome 
D) its destruction by a process initiated by the activity of its complex with Cdk 
E) the binding of PDGF to receptors on the cell surface 
A) an increase in production once the restriction point is passed 
B) the cascade of increased production once its protein is phosphorylated by Cdk 
C) the changing ratio of cytoplasm to genome 
D) its destruction by a process initiated by the activity of its complex with Cdk 
E) the binding of PDGF to receptors on the cell surface

Question 5

A mutation results in a cell that no longer produces a normal protein kinase for the M phase checkpoint. Which of the following would likely be the immediate result of this mutation?

Accepted Answer

A) The cell would prematurely enter anaphase. 
B) The cell would never leave metaphase. 
C) The cell would never enter metaphase. 
D) The cell would never enter prophase. 
E) The cell would undergo normal mitosis, but fail to enter the next G₁ phase. 
A) The cell would prematurely enter anaphase. 
B) The cell would never leave metaphase. 
C) The cell would never enter metaphase. 
D) The cell would never enter prophase. 
E) The cell would undergo normal mitosis, but fail to enter the next G₁ phase.

Question 6

-If the cell whose nuclear material is shown in the figure above continues toward completion of mitosis, which of the following events would occur next?

Accepted Answer

A) cell membrane synthesis 
B) spindle fibre formation 
C) nuclear envelope breakdown 
D) formation of telophase nuclei 
E) synthesis of chromatids 
A) cell membrane synthesis 
B) spindle fibre formation 
C) nuclear envelope breakdown 
D) formation of telophase nuclei 
E) synthesis of chromatids

Question 7

Why do neurons and some other specialized cells divide infrequently?

Accepted Answer

A) They no longer have active nuclei. 
B) They no longer carry receptors for signal molecules. 
C) They have been shunted into G₀. 
D) They can no longer bind Cdk to cyclin. 
E) They show a drop in MPF concentration. 
A) They no longer have active nuclei. 
B) They no longer carry receptors for signal molecules. 
C) They have been shunted into G₀. 
D) They can no longer bind Cdk to cyclin. 
E) They show a drop in MPF concentration.

Question 8

A plant-derived protein known as colchicine can be used to poison cells by blocking the formation of the spindle. Which of the following would result if colchicine is added to a sample of cells in G₂?

Accepted Answer

A) The cells would immediately die. 
B) The cells would be unable to begin M and stay in G₂. 
C) The chromosomes would coil and shorten but have no spindle to attach to. 
D) The chromosomes would segregate but in a disorderly pattern. 
E) Each resultant daughter cell would also be unable to form a spindle. 
A) The cells would immediately die. 
B) The cells would be unable to begin M and stay in G₂. 
C) The chromosomes would coil and shorten but have no spindle to attach to. 
D) The chromosomes would segregate but in a disorderly pattern. 
E) Each resultant daughter cell would also be unable to form a spindle.

Question 9

Use the following information to answer the questions below.
A research team established similar lymphocyte cultures from a number of human donors, including healthy teenagers of both genders, patients already suffering from long-term bacterial infections, and elderly volunteers. They found that the increase in lymphocyte incorporation after pathogen introduction was slightly lower in some of the female teenagers and significantly lower in each of the elderly persons. They repeated the study with a larger number of samples but got the same results.
-What might be among the research team's conclusions?

Accepted Answer

A) The young women showed these results because they have poorer nutrition. 
B) The elderly persons' samples demonstrated their lowered immune responses. 
C) The young men had higher responses because they are generally healthier. 
D) The patient samples should have had the lowest response but did not, so the experiment is invalid. 
E) The elderly donor samples represent cells no longer capable of any cell division. 
A) The young women showed these results because they have poorer nutrition. 
B) The elderly persons' samples demonstrated their lowered immune responses. 
C) The young men had higher responses because they are generally healthier. 
D) The patient samples should have had the lowest response but did not, so the experiment is invalid. 
E) The elderly donor samples represent cells no longer capable of any cell division.

Question 10

The MPF protein complex turns itself off by

Accepted Answer

A) activating a process that destroys cyclin components. 
B) activating an enzyme that stimulates cyclin. 
C) binding to chromatin. 
D) exiting the cell. 
E) activating the anaphase-promoting complex. 
A) activating a process that destroys cyclin components. 
B) activating an enzyme that stimulates cyclin. 
C) binding to chromatin. 
D) exiting the cell. 
E) activating the anaphase-promoting complex.

Question 11

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

Question 12

Only once all kinetochores are attached to spindle microtubules can ________ proceed.

Accepted Answer

A) metaphase 
B) anaphase 
C) synthesis 
D) MPF 
E) G₀ 
A) metaphase 
B) anaphase 
C) synthesis 
D) MPF 
E) G₀

Question 13

Which of the following best describes how chromosomes move toward the poles of the spindle during mitosis?

Accepted Answer

A) The chromosomes are "reeled in" by the contraction of spindle microtubules. 
B) Motor proteins of the kinetochores move the chromosomes along the spindle microtubules. 
C) Nonkinetochore spindle fibres serve to push chromosomes in the direction of the poles. 
D) The chromosomes are "reeled in" by the contraction of spindle microtubules, and motor proteins of the kinetochores move the chromosomes along the spindle microtubules. 
E) The chromosomes are "reeled in" by the contraction of spindle microtubules, motor proteins of the kinetochores move the chromosomes along the spindle microtubules, and nonkinetochore spindle fibres serve to push chromosomes in the direction of the poles. 
A) The chromosomes are "reeled in" by the contraction of spindle microtubules. 
B) Motor proteins of the kinetochores move the chromosomes along the spindle microtubules. 
C) Nonkinetochore spindle fibres serve to push chromosomes in the direction of the poles. 
D) The chromosomes are "reeled in" by the contraction of spindle microtubules, and motor proteins of the kinetochores move the chromosomes along the spindle microtubules. 
E) The chromosomes are "reeled in" by the contraction of spindle microtubules, motor proteins of the kinetochores move the chromosomes along the spindle microtubules, and nonkinetochore spindle fibres serve to push chromosomes in the direction of the poles.

Question 14

The following information applies to the questions below.
Several organisms, primarily protists, have what are called intermediate mitotic organization.
-These protists are intermediate in what sense?

Accepted Answer

A) They reproduce by binary fission in their early stages of development and by mitosis when they are mature. 
B) They never coil up their chromosomes when they are dividing. 
C) They use mitotic division but only have circular chromosomes. 
D) They maintain a nuclear envelope during division. 
E) None of them form spindles. 
A) They reproduce by binary fission in their early stages of development and by mitosis when they are mature. 
B) They never coil up their chromosomes when they are dividing. 
C) They use mitotic division but only have circular chromosomes. 
D) They maintain a nuclear envelope during division. 
E) None of them form spindles.

Question 15

Suppose a biologist can separate one of a dozen pieces of chromatin from a eukaryotic (animal)nucleus. It might consist of which of the following?

Accepted Answer

A) one-twelfth of the genes of the organism 
B) two chromosomes, each with six chromatids 
C) a single circular piece of DNA 
D) two long strands of DNA plus proteins 
E) two chromatids attached together at a centromere 
A) one-twelfth of the genes of the organism 
B) two chromosomes, each with six chromatids 
C) a single circular piece of DNA 
D) two long strands of DNA plus proteins 
E) two chromatids attached together at a centromere

Question 16

You observe cells under the microscope and notice that, as they undergo mitosis, the nucleus remains intact. You conclude that these cells are

Accepted Answer

A) animal cells. 
B) plant cells. 
C) bacteria. 
D) diatoms. 
E) tumour cells. 
A) animal cells. 
B) plant cells. 
C) bacteria. 
D) diatoms. 
E) tumour cells.

Question 17

Which of the following most accurately describes a cyclin?

Accepted Answer

A) It is present in similar concentrations throughout the cell cycle. 
B) It is activated to phosphorylate by complexing with a Cdk. 
C) It decreases in concentration when MPF activity increases. 
D) It activates a Cdk molecule when it is in sufficient concentration. 
E) It activates a Cdk when its concentration is decreased. 
A) It is present in similar concentrations throughout the cell cycle. 
B) It is activated to phosphorylate by complexing with a Cdk. 
C) It decreases in concentration when MPF activity increases. 
D) It activates a Cdk molecule when it is in sufficient concentration. 
E) It activates a Cdk when its concentration is decreased.

Question 18

Use the following information to answer the questions below.
The lettered circle in the figure below shows a diploid nucleus with four chromosomes. There are two pairs of homologous chromosomes, one long and the other short. One haploid set is symbolized as black and the other haploid set is grey. The chromosomes in the unlettered circle have not yet replicated. Choose the correct chromosomal conditions for the following stages.
  
-What is the correct chromosomal condition for one daughter nucleus at telophase of mitosis?

Accepted Answer

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

Question 19

For a newly evolving protist, what would be the advantage of using eukaryote-like cell division rather than prokaryotic binary fission?

Accepted Answer

A) Binary fission would not allow for the formation of new organisms. 
B) Cell division would allow for the orderly and efficient segregation of multiple linear chromosomes. 
C) Cell division would be faster than binary fission. 
D) Cell division allows for lower rates of error per chromosome replication. 
E) Binary fission would not allow the organism to have complex cells. 
A) Binary fission would not allow for the formation of new organisms. 
B) Cell division would allow for the orderly and efficient segregation of multiple linear chromosomes. 
C) Cell division would be faster than binary fission. 
D) Cell division allows for lower rates of error per chromosome replication. 
E) Binary fission would not allow the organism to have complex cells.

Question 20

The following questions are based on the following figure.
  
-G₁ is represented by which numbered part(s)of the cycle?

Accepted Answer

A) I or V 
B) II or IV 
C) III only 
D) IV only 
E) V only 
A) I or V 
B) II or IV 
C) III only 
D) IV only 
E) V only

Exam 12: The Cell Cycle

If cells in the process of dividing are subjected to colchicine, a drug that interferes with the formation of the spindle apparatus, at which stage will mitosis be arrested?

Which of the following is true concerning cancer cells?

The following information applies to the questions below. 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 causes the decrease in the amount of cyclin at a specific point in the cell cycle?

A mutation results in a cell that no longer produces a normal protein kinase for the M phase checkpoint. Which of the following would likely be the immediate result of this mutation?

-If the cell whose nuclear material is shown in the figure above continues toward completion of mitosis, which of the following events would occur next?

Why do neurons and some other specialized cells divide infrequently?

A plant-derived protein known as colchicine can be used to poison cells by blocking the formation of the spindle. Which of the following would result if colchicine is added to a sample of cells in G₂?

The MPF protein complex turns itself off by

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

Only once all kinetochores are attached to spindle microtubules can ________ proceed.

Which of the following best describes how chromosomes move toward the poles of the spindle during mitosis?

The following information applies to the questions below. Several organisms, primarily protists, have what are called intermediate mitotic organization. -These protists are intermediate in what sense?

Suppose a biologist can separate one of a dozen pieces of chromatin from a eukaryotic (animal)nucleus. It might consist of which of the following?

You observe cells under the microscope and notice that, as they undergo mitosis, the nucleus remains intact. You conclude that these cells are

Which of the following most accurately describes a cyclin?

For a newly evolving protist, what would be the advantage of using eukaryote-like cell division rather than prokaryotic binary fission?

The following questions are based on the following figure. -G₁ is represented by which numbered part(s)of the cycle?

Introduction: Evolution and Themes of Biology

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

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

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 Signalling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behaviour

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems and Restoration Ecology

Conservation Biology and Global Change

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