Question 1

A particular cell has half as much DNA as some other cells in a mitotically active tissue. The cell in question is most likely in

Accepted Answer

A) G₁ 
B) G₂. 
C) prophase. 
D) metaphase. 
E) anaphase. 
A) G₁ 
B) G₂. 
C) prophase. 
D) metaphase. 
E) anaphase.

Question 2

Cells that are in a nondividing state are in which phase?

Accepted Answer

A) G₀ 
B) G₂ 
C) G₁ 
D) S 
E) M 
A) G₀ 
B) G₂ 
C) G₁ 
D) S 
E) M

Question 3

The formation of a cell plate is beginning across the middle of a cell and nuclei are re-forming at opposite ends of the cell. What kind of cell is this?

Accepted Answer

A) an animal cell in metaphase 
B) an animal cell in telophase 
C) an animal cell undergoing cytokinesis 
D) a plant cell in metaphase 
E) a plant cell undergoing cytokinesis 
A) an animal cell in metaphase 
B) an animal cell in telophase 
C) an animal cell undergoing cytokinesis 
D) a plant cell in metaphase 
E) a plant cell undergoing cytokinesis

Question 4

Density-dependent inhibition is explained by which of the following?

Accepted Answer

A) As cells become more numerous, they begin to squeeze against each other, restricting their size and ability to produce control factors. 
B) As cells become more numerous, the cell surface proteins of one cell contact the adjoining cells and they 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, more and more of them enter the S phase of the cell cycle. 
E) As cells become more numerous, the level of waste products increases, eventually slowing down metabolism. 
A) As cells become more numerous, they begin to squeeze against each other, restricting their size and ability to produce control factors. 
B) As cells become more numerous, the cell surface proteins of one cell contact the adjoining cells and they 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, more and more of them enter the S phase of the cell cycle. 
E) As cells become more numerous, the level of waste products increases, eventually slowing down metabolism.

Question 5

The following questions are based on Figure 12.3.
  
-In the figure above, mitosis is represented by which number?

Accepted Answer

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

Question 6

During which phases of mitosis are chromosomes composed of two chromatids?

Accepted Answer

A) from interphase through anaphase 
B) from G₁ of interphase through metaphase 
C) from metaphase through telophase 
D) from anaphase through telophase 
E) from G₂ of interphase through metaphase 
A) from interphase through anaphase 
B) from G₁ of interphase through metaphase 
C) from metaphase through telophase 
D) from anaphase through telophase 
E) from G₂ of interphase through metaphase

Question 7

Use the following information to answer the questions below.
The lettered circle in Figure 12.1 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 gray. The chromosomes in the unlettered circle have not yet replicated. Choose the correct chromosomal conditions for the following stages.

-A cell containing 92 chromatids at metaphase of mitosis would, at its completion, produce two nuclei each containing how many chromosomes?

Accepted Answer

A) 12 
B) 16 
C) 23 
D) 46 
E) 92 
A) 12 
B) 16 
C) 23 
D) 46 
E) 92

Question 8

Measurements of the amount of DNA per nucleus were taken on a large number of cells from a growing fungus. The measured DNA levels ranged from 3 to 6 picograms per nucleus. In which stage of the cell cycle was the nucleus with 6 picograms of DNA?

Accepted Answer

A) G₀ 
B) G₁ 
C) S 
D) G₂ 
E) M 
A) G₀ 
B) G₁ 
C) S 
D) G₂ 
E) M

Question 9

Which of the following describe(s)cyclin-dependent kinase (Cdk)?

Accepted Answer

A) Cdk is inactive, or "turned off," in the presence of cyclin. 
B) Cdk is present throughout the cell cycle. 
C) Cdk is an enzyme that attaches phosphate groups to other proteins. 
D) Both A and B are True. 
E) Both B and C are True. 
A) Cdk is inactive, or "turned off," in the presence of cyclin. 
B) Cdk is present throughout the cell cycle. 
C) Cdk is an enzyme that attaches phosphate groups to other proteins. 
D) Both A and B are True. 
E) Both B and C are True.

Question 10

Use the following information to answer the questions below.
The lettered circle in Figure 12.1 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 gray. The chromosomes in the unlettered circle have not yet replicated. Choose the correct chromosomal conditions for the following stages.

-If cells in the process of dividing are subjected to colchicine, a drug that interferes with the functioning 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 11

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) Non-kinetochore spindle fibers serve to push chromosomes in the direction of the poles. 
D) both A and B 
E) A, B, and C 
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) Non-kinetochore spindle fibers serve to push chromosomes in the direction of the poles. 
D) both A and B 
E) A, B, and C

Question 12

Figure 12.2  
-If there are 20 chromatids in a cell at metaphase, how many chromosomes are there in each daughter cell following cytokinesis?

Accepted Answer

A) 10 
B) 20 
C) 30 
D) 40 
E) 80 
A) 10 
B) 20 
C) 30 
D) 40 
E) 80

Question 13

Starting with a fertilized egg (zygote), a series of five cell divisions would produce an early embryo with how many cells?

Accepted Answer

A) 4 
B) 8 
C) 16 
D) 32 
E) 64 
A) 4 
B) 8 
C) 16 
D) 32 
E) 64

Question 14

A particular cyclin called cyclin E forms a complex with a cyclin-dependent kinase called Cdk 2. This complex is important for the progression of the cell from G₁ into the S phase of the cell cycle. Which of the following statements is correct?

Accepted Answer

A) The amount of cyclin E is greatest during the S phase. 
B) The amount of Cdk 2 is greater during G₁ compared to the S phase. 
C) The amount of cyclin E is highest during G₁. 
D) The amount of Cdk 2 is greatest during G₁. 
E) The activity of the cyclin E/Cdk 2 complex is highest during G₂. 
A) The amount of cyclin E is greatest during the S phase. 
B) The amount of Cdk 2 is greater during G₁ compared to the S phase. 
C) The amount of cyclin E is highest during G₁. 
D) The amount of Cdk 2 is greatest during G₁. 
E) The activity of the cyclin E/Cdk 2 complex is highest during G₂.

Question 15

Imagine looking through a microscope at a squashed onion root tip. The chromosomes of many of the cells are plainly visible. In some cells, replicated chromosomes are aligned along the center (equator)of the cell. These particular cells are in which stage of mitosis?

Accepted Answer

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

Question 16

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

Accepted Answer

A) PDGF 
B) MPF 
C) protein kinase 
D) cyclin 
E) Cdk 
A) PDGF 
B) MPF 
C) protein kinase 
D) cyclin 
E) Cdk

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

Question 18

The research team used the setup to study the incorporation of labeled nucleotides into a culture of lymphocytes and found that the lymphocytes incorporated the labeled nucleotide at a significantly higher level after a pathogen was introduced into the culture. They concluded that

Accepted Answer

A) the presence of the pathogen made the experiment too contaminated to trust the results. 
B) their tissue culture methods needed to be relearned. 
C) infection causes lymphocytes to divide more rapidly. 
D) infection causes cell cultures in general to reproduce more rapidly. 
E) infection causes lymphocyte cultures to skip some parts of the cell cycle. 
A) the presence of the pathogen made the experiment too contaminated to trust the results. 
B) their tissue culture methods needed to be relearned. 
C) infection causes lymphocytes to divide more rapidly. 
D) infection causes cell cultures in general to reproduce more rapidly. 
E) infection causes lymphocyte cultures to skip some parts of the cell cycle.

Question 19

Why do chromosomes coil during mitosis?

Accepted Answer

A) to increase their potential energy 
B) to allow the chromosomes to move without becoming entangled and breaking 
C) to allow the chromosomes to fit within the nuclear envelope 
D) to allow the sister chromatids to remain attached 
E) to provide for the structure of the centromere 
A) to increase their potential energy 
B) to allow the chromosomes to move without becoming entangled and breaking 
C) to allow the chromosomes to fit within the nuclear envelope 
D) to allow the sister chromatids to remain attached 
E) to provide for the structure of the centromere

Question 20

Which of the following is a protein synthesized at specific times during the cell cycle that associates with a kinase to form a catalytically active complex?

Accepted Answer

A) PDGF 
B) MPF 
C) protein kinase 
D) cyclin 
E) Cdk 
A) PDGF 
B) MPF 
C) protein kinase 
D) cyclin 
E) Cdk

Exam 12: The Cell Cycle

A particular cell has half as much DNA as some other cells in a mitotically active tissue. The cell in question is most likely in

Cells that are in a nondividing state are in which phase?

The formation of a cell plate is beginning across the middle of a cell and nuclei are re-forming at opposite ends of the cell. What kind of cell is this?

Density-dependent inhibition is explained by which of the following?

The following questions are based on Figure 12.3. -In the figure above, mitosis is represented by which number?

During which phases of mitosis are chromosomes composed of two chromatids?

Measurements of the amount of DNA per nucleus were taken on a large number of cells from a growing fungus. The measured DNA levels ranged from 3 to 6 picograms per nucleus. In which stage of the cell cycle was the nucleus with 6 picograms of DNA?

Which of the following describe(s)cyclin-dependent kinase (Cdk)?

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

Figure 12.2 -If there are 20 chromatids in a cell at metaphase, how many chromosomes are there in each daughter cell following cytokinesis?

Starting with a fertilized egg (zygote), a series of five cell divisions would produce an early embryo with how many cells?

A particular cyclin called cyclin E forms a complex with a cyclin-dependent kinase called Cdk 2. This complex is important for the progression of the cell from G₁ into the S phase of the cell cycle. Which of the following statements is correct?

Imagine looking through a microscope at a squashed onion root tip. The chromosomes of many of the cells are plainly visible. In some cells, replicated chromosomes are aligned along the center (equator)of the cell. These particular cells are in which stage of mitosis?

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

Which of the following does not occur during mitosis?

The research team used the setup to study the incorporation of labeled nucleotides into a culture of lymphocytes and found that the lymphocytes incorporated the labeled nucleotide at a significantly higher level after a pathogen was introduced into the culture. They concluded that

Why do chromosomes coil during mitosis?

Which of the following is a protein synthesized at specific times during the cell cycle that associates with a kinase to form a catalytically active complex?

Introduction: Themes in the Study of Life

The Chemical Context of Life

Water and the Fitness of the Environment

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: Harvesting Chemical Energy

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

Control of Gene Expression

Viruses

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 Introduction to Animal Diversity

Invertebrates

Vertebrates

Plant Structure, Growth, and Development

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

Conservation Biology and Restoration Ecology

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