Question 1

Which of the following was a discovery that had to be made before human chromosomes could be correctly counted?

Accepted Answer

A)  how to use a hypotonic solution to swell nuclei 
B)  how to visualize sperm nuclei 
C)  how to visualize chromosomes 
D)  when to see chromosomes separate from one another 
E)  when to see chromosomes in pairs 
A)  how to use a hypotonic solution to swell nuclei 
B)  how to visualize sperm nuclei 
C)  how to visualize chromosomes 
D)  when to see chromosomes separate from one another 
E)  when to see chromosomes in pairs

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 growing 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 growing in culture.

Question 3

The following questions are based on Figure 12.3.
   
Figure 12.3
-At which of the numbered regions would you expect to find cells at metaphase?

Accepted Answer

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

Question 4

Cells from an advanced malignant tumor most often have very abnormal chromosomes, and often an abnormal total number of chromosomes. Why might this occur?

Accepted Answer

A)  Cancer cells are no longer density dependent. 
B)  Cancer cells are no longer anchorage dependent. 
C)  Chromosomally abnormal cells can still go through cell cycle checkpoints. 
D)  Chromosomally abnormal cells still have normal metabolism. 
E)  Transformation introduces new chromosomes into cells. 
A)  Cancer cells are no longer density dependent. 
B)  Cancer cells are no longer anchorage dependent. 
C)  Chromosomally abnormal cells can still go through cell cycle checkpoints. 
D)  Chromosomally abnormal cells still have normal metabolism. 
E)  Transformation introduces new chromosomes into cells.

Question 5

Which of the following is a function of those spindle microtubules that do not attach to kinetochores?

Accepted Answer

A)  maintaining an appropriate spacing among the moving chromosomes 
B)  producing a cleavage furrow when telophase is complete 
C)  providing the ATP needed by the fibers attached to kinetochores 
D)  maintaining the region of overlap of microtubules in the cell's center 
E)  pulling the poles of the spindles closer to one another 
A)  maintaining an appropriate spacing among the moving chromosomes 
B)  producing a cleavage furrow when telophase is complete 
C)  providing the ATP needed by the fibers attached to kinetochores 
D)  maintaining the region of overlap of microtubules in the cell's center 
E)  pulling the poles of the spindles closer to one another

Question 6

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 7

Use the following information to answer the questions below.
Nucleotides can be radiolabeled before they are incorporated into newly forming DNA and can therefore be assayed to track their incorporation. In a set of experiments, a student-faculty research team used labeled T nucleotides and introduced these into the culture of dividing human cells at specific times.
-Which of the following questions might be answered by such a method?

Accepted Answer

A)  How many cells are produced by the culture per hour? 
B)  What is the length of the S phase of the cell cycle? 
C)  When is the S chromosome synthesized? 
D)  How many picograms of DNA are made per cell cycle? 
E)  When do spindle fibers attach to chromosomes? 
A)  How many cells are produced by the culture per hour? 
B)  What is the length of the S phase of the cell cycle? 
C)  When is the S chromosome synthesized? 
D)  How many picograms of DNA are made per cell cycle? 
E)  When do spindle fibers attach to chromosomes?

Question 8

Use the following information to answer the questions below.
A student is looking through his light microscope (~450 X) at a squashed and stained onion root tip. Some, but not all, of the cells have clearly visible chromosome strands.
-When a cell is in anaphase of mitosis, which of the following will he see?

Accepted Answer

A)  a clear area in the center of the cell 
B)  chromosomes clustered at the poles 
C)  individual chromatids separating 
D)  chromosomes clustered tightly at the center 
E)  formation of vesicles at the midline 
A)  a clear area in the center of the cell 
B)  chromosomes clustered at the poles 
C)  individual chromatids separating 
D)  chromosomes clustered tightly at the center 
E)  formation of vesicles at the midline

Question 9

Use the data in Table 12.1 to answer the following questions.
The data were obtained from a study of the length of time spent in each phase of the cell cycle by cells of three eukaryotic organisms designated beta, delta, and gamma.
   
Table 12.1: Minutes Spent in Cell Cycle Phases
-The best conclusion concerning delta is that the cells

Accepted Answer

A)  contain no DNA. 
B)  contain no RNA. 
C)  contain only one chromosome that is very short. 
D)  are actually in the G₀ phase. 
E)  divide in the G₁ phase. 
A)  contain no DNA. 
B)  contain no RNA. 
C)  contain only one chromosome that is very short. 
D)  are actually in the G₀ phase. 
E)  divide in the G₁ phase.

Question 10

In which group of eukaryotic organisms does the nuclear envelope remain intact during mitosis?

Accepted Answer

A)  seedless plants 
B)  dinoflagellates 
C)  diatoms 
D)  dinoflagellates and diatoms only 
E)  seedless plants, dinoflagellates, and diatoms 
A)  seedless plants 
B)  dinoflagellates 
C)  diatoms 
D)  dinoflagellates and diatoms only 
E)  seedless plants, dinoflagellates, and diatoms

Question 11

Use the following information to answer the questions below.
The 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 12

The following questions are based on Figure 12.3.
   
Figure 12.3
-Which number represents the point in the cell cycle during which the chromosomes are replicated?

Accepted Answer

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

Question 13

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 which to attach. 
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 which to attach. 
D)  The chromosomes would segregate but in a disorderly pattern. 
E)  Each resultant daughter cell would also be unable to form a spindle.

Question 14

You have the technology necessary to measure each of the following in a sample of animal cells: chlorophylls, organelle density, picograms of DNA, cell wall components, and enzymatic activity. Which would you expect to increase significantly from M to G₁?

Accepted Answer

A)  organelle density and enzymatic activity 
B)  cell wall components and DNA 
C)  chlorophyll and cell walls 
D)  organelle density and cell walls 
E)  chlorophyll and DNA 
A)  organelle density and enzymatic activity 
B)  cell wall components and DNA 
C)  chlorophyll and cell walls 
D)  organelle density and cell walls 
E)  chlorophyll and DNA

Question 15

The following questions are based on Figure 12.3.
   
Figure 12.3
-MPF reaches its threshold concentration at the end of this stage.

Accepted Answer

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

Question 16

Where do the microtubules of the spindle originate during mitosis in both plant and animal cells?

Accepted Answer

A)  centromere 
B)  centrosome 
C)  centriole 
D)  chromatid 
E)  kinetochore 
A)  centromere 
B)  centrosome 
C)  centriole 
D)  chromatid 
E)  kinetochore

Question 17

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 18

Which of the following is a protein maintained at constant levels throughout the cell cycle that requires cyclin to become catalytically active?

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 19

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

Exam 12: The Cell Cycle

Which of the following was a discovery that had to be made before human chromosomes could be correctly counted?

Which of the following is true concerning cancer cells?

The following questions are based on Figure 12.3. Figure 12.3 -At which of the numbered regions would you expect to find cells at metaphase?

Cells from an advanced malignant tumor most often have very abnormal chromosomes, and often an abnormal total number of chromosomes. Why might this occur?

Which of the following is a function of those spindle microtubules that do not attach to kinetochores?

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

In which group of eukaryotic organisms does the nuclear envelope remain intact during mitosis?

The following questions are based on Figure 12.3. Figure 12.3 -Which number represents the point in the cell cycle during which the chromosomes are replicated?

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?

You have the technology necessary to measure each of the following in a sample of animal cells: chlorophylls, organelle density, picograms of DNA, cell wall components, and enzymatic activity. Which would you expect to increase significantly from M to G₁?

The following questions are based on Figure 12.3. Figure 12.3 -MPF reaches its threshold concentration at the end of this stage.

Where do the microtubules of the spindle originate during mitosis in both plant and animal cells?

Why do chromosomes coil during mitosis?

Which of the following is a protein maintained at constant levels throughout the cell cycle that requires cyclin to become catalytically active?

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

Introduction: Themes in the Study of Life

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

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 Signaling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behavior

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems and Restoration Ecology

Conservation Biology and Global Change

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