Question 1

Which of the following statements is True of chromatin?

Accepted Answer

A) Heterochromatin is composed of DNA, whereas euchromatin is made of DNA and RNA. 
B) Both heterochromatin and euchromatin are found in the cytoplasm. 
C) Heterochromatin is highly condensed, whereas euchromatin is less compact. 
D) Euchromatin is not transcribed, whereas heterochromatin is transcribed. 
E) Only euchromatin is visible under the light microscope. 
A) Heterochromatin is composed of DNA, whereas euchromatin is made of DNA and RNA. 
B) Both heterochromatin and euchromatin are found in the cytoplasm. 
C) Heterochromatin is highly condensed, whereas euchromatin is less compact. 
D) Euchromatin is not transcribed, whereas heterochromatin is transcribed. 
E) Only euchromatin is visible under the light microscope.

Question 2

What does transformation involve in bacteria?

Accepted Answer

A) the creation of a strand of DNA from an RNA molecule 
B) the creation of a strand of RNA from a DNA molecule 
C) the infection of cells by a phage DNA molecule 
D) the type of semiconservative replication shown by DNA 
E) assimilation of external DNA into a cell 
A) the creation of a strand of DNA from an RNA molecule 
B) the creation of a strand of RNA from a DNA molecule 
C) the infection of cells by a phage DNA molecule 
D) the type of semiconservative replication shown by DNA 
E) assimilation of external DNA into a cell

Question 3

Which of the following removes the RNA nucleotides from the primer and adds equivalent DNA nucleotides to the 3' end of Okazaki fragments?

Accepted Answer

A) helicase 
B) DNA polymerase III 
C) ligase 
D) DNA polymerase I 
E) primase 
A) helicase 
B) DNA polymerase III 
C) ligase 
D) DNA polymerase I 
E) primase

Question 4

Which of the following best describes the addition of nucleotides to a growing DNA chain?

Accepted Answer

A) A nucleoside triphosphate is added to the 5' end of the DNA, releasing a molecule of pyrophosphate. 
B) A nucleoside triphosphate is added to the 3' end of the DNA, releasing a molecule of pyrophosphate. 
C) A nucleoside diphosphate is added to the 5' end of the DNA, releasing a molecule of phosphate. 
D) A nucleoside diphosphate is added to the 3' end of the DNA, releasing a molecule of phosphate. 
E) A nucleoside monophosphate is added to the 5' end of the DNA. 
A) A nucleoside triphosphate is added to the 5' end of the DNA, releasing a molecule of pyrophosphate. 
B) A nucleoside triphosphate is added to the 3' end of the DNA, releasing a molecule of pyrophosphate. 
C) A nucleoside diphosphate is added to the 5' end of the DNA, releasing a molecule of phosphate. 
D) A nucleoside diphosphate is added to the 3' end of the DNA, releasing a molecule of phosphate. 
E) A nucleoside monophosphate is added to the 5' end of the DNA.

Question 5

The leading and the lagging strands differ in that

Accepted Answer

A) the leading strand is synthesized in the same direction as the movement of the replication fork, and the lagging strand is synthesized in the opposite direction. 
B) the leading strand is synthesized by adding nucleotides to the 3' end of the growing strand, and the lagging strand is synthesized by adding nucleotides to the 5' end. 
C) the lagging strand is synthesized continuously, whereas the leading strand is synthesized in short fragments that are ultimately stitched together. 
D) the leading strand is synthesized at twice the rate of the lagging strand. 
A) the leading strand is synthesized in the same direction as the movement of the replication fork, and the lagging strand is synthesized in the opposite direction. 
B) the leading strand is synthesized by adding nucleotides to the 3' end of the growing strand, and the lagging strand is synthesized by adding nucleotides to the 5' end. 
C) the lagging strand is synthesized continuously, whereas the leading strand is synthesized in short fragments that are ultimately stitched together. 
D) the leading strand is synthesized at twice the rate of the lagging strand.

Question 6

In analyzing the number of different bases in a DNA sample, which result would be consistent with the base-pairing rules?

Accepted Answer

A) A = G 
B) A + G = C + T 
C) A + T = G + T 
D) A = C 
E) G = T 
A) A = G 
B) A + G = C + T 
C) A + T = G + T 
D) A = C 
E) G = T

Question 7

Which of the following separates the DNA strands during replication?

Accepted Answer

A) helicase 
B) DNA polymerase III 
C) ligase 
D) DNA polymerase I 
E) primase 
A) helicase 
B) DNA polymerase III 
C) ligase 
D) DNA polymerase I 
E) primase

Question 8

What kind of chemical bond is found between paired bases of the DNA double helix?

Accepted Answer

A) hydrogen 
B) ionic 
C) covalent 
D) sulfhydryl 
E) phosphate 
A) hydrogen 
B) ionic 
C) covalent 
D) sulfhydryl 
E) phosphate

Question 9

In a linear eukaryotic chromatin sample, which of the following strands is looped into domains by scaffolding?

Accepted Answer

A) DNA without attached histones 
B) DNA with H1 only 
C) the 10 nm chromatin fiber 
D) the 30 nm chromatin fiber 
E) the metaphase chromosome 
A) DNA without attached histones 
B) DNA with H1 only 
C) the 10 nm chromatin fiber 
D) the 30 nm chromatin fiber 
E) the metaphase chromosome

Question 10

Studies of nucleosomes have shown that histones (except H1)exist in each nucleosome as two kinds of tetramers: one of 2 H2A molecules and 2 H2B molecules, and the other as 2 H3 and 2 H4 molecules. Which of the following is supported by this data?

Accepted Answer

A) DNA can wind itself around either of the two kinds of tetramers. 
B) The two types of tetramers associate to form an octamer. 
C) DNA has to associate with individual histones before they form tetramers. 
D) Only H2A can form associations with DNA molecules. 
E) The structure of H3 and H4 molecules is not basic like that of the other histones. 
A) DNA can wind itself around either of the two kinds of tetramers. 
B) The two types of tetramers associate to form an octamer. 
C) DNA has to associate with individual histones before they form tetramers. 
D) Only H2A can form associations with DNA molecules. 
E) The structure of H3 and H4 molecules is not basic like that of the other histones.

Question 11

E) coli cells grown on ¹⁵N medium are transferred to ¹⁴N medium and allowed to grow for two more generations (two rounds of DNA replication). DNA extracted from these cells is centrifuged. What density distribution of DNA would you expect in this experiment?

Accepted Answer

A) one high-density and one low-density band 
B) one intermediate-density band 
C) one high-density and one intermediate-density band 
D) one low-density and one intermediate-density band 
E) one low-density band 
A) one high-density and one low-density band 
B) one intermediate-density band 
C) one high-density and one intermediate-density band 
D) one low-density and one intermediate-density band 
E) one low-density band

Question 12

A new DNA strand elongates only in the 5' to 3' direction because

Accepted Answer

A) DNA polymerase begins adding nucleotides at the 5' end of the template. 
B) Okazaki fragments prevent elongation in the 3' to 5' direction. 
C) the polarity of the DNA molecule prevents addition of nucleotides at the 3' end. 
D) replication must progress toward the replication fork. 
E) DNA polymerase can only add nucleotides to the free 3' end. 
A) DNA polymerase begins adding nucleotides at the 5' end of the template. 
B) Okazaki fragments prevent elongation in the 3' to 5' direction. 
C) the polarity of the DNA molecule prevents addition of nucleotides at the 3' end. 
D) replication must progress toward the replication fork. 
E) DNA polymerase can only add nucleotides to the free 3' end.

Question 13

Replication in prokaryotes differs from replication in eukaryotes for which of these reasons?

Accepted Answer

A) The prokaryotic chromosome has histones, whereas eukaryotic chromosomes do not. 
B) Prokaryotic chromosomes have a single origin of replication, whereas eukaryotic chromosomes have many. 
C) The rate of elongation during DNA replication is slower in prokaryotes than in eukaryotes. 
D) Prokaryotes produce Okazaki fragments during DNA replication, but eukaryotes do not. 
E) Prokaryotes have telomeres, and eukaryotes do not. 
A) The prokaryotic chromosome has histones, whereas eukaryotic chromosomes do not. 
B) Prokaryotic chromosomes have a single origin of replication, whereas eukaryotic chromosomes have many. 
C) The rate of elongation during DNA replication is slower in prokaryotes than in eukaryotes. 
D) Prokaryotes produce Okazaki fragments during DNA replication, but eukaryotes do not. 
E) Prokaryotes have telomeres, and eukaryotes do not.

Question 14

Which of the following help to hold the DNA strands apart while they are being replicated?

Accepted Answer

A) primase 
B) ligase 
C) DNA polymerase 
D) single-strand binding proteins 
E) exonuclease 
A) primase 
B) ligase 
C) DNA polymerase 
D) single-strand binding proteins 
E) exonuclease

Question 15

The following scientists made significant contributions to our understanding of the structure and function of DNA. Place the scientists' names in the correct chronological order, starting with the first scientist(s)to make a contribution. I. Avery, McCarty, and MacLeod
II. Griffith
III. Hershey and Chase
IV. Meselson and Stahl
V. Watson and Crick

Accepted Answer

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

Question 16

What is the function of DNA polymerase III?

Accepted Answer

A) to unwind the DNA helix during replication 
B) to seal together the broken ends of DNA strands 
C) to add nucleotides to the end of a growing DNA strand 
D) to degrade damaged DNA molecules 
E) to rejoin the two DNA strands (one new and one old)after replication 
A) to unwind the DNA helix during replication 
B) to seal together the broken ends of DNA strands 
C) to add nucleotides to the end of a growing DNA strand 
D) to degrade damaged DNA molecules 
E) to rejoin the two DNA strands (one new and one old)after replication

Question 17

Use Figure 16.1 to answer the following questions.
   
Figure 16.1
-The enzyme telomerase solves the problem of replication at the ends of linear chromosomes by which method?

Accepted Answer

A) adding a single 5' cap structure that resists degradation by nucleases 
B) causing specific double strand DNA breaks that result in blunt ends on both strands 
C) causing linear ends of the newly replicated DNA to circularize 
D) adding numerous short DNA sequences such as TTAGGG, which form a hairpin turn 
E) adding numerous GC pairs which resist hydrolysis and maintain chromosome integrity 
A) adding a single 5' cap structure that resists degradation by nucleases 
B) causing specific double strand DNA breaks that result in blunt ends on both strands 
C) causing linear ends of the newly replicated DNA to circularize 
D) adding numerous short DNA sequences such as TTAGGG, which form a hairpin turn 
E) adding numerous GC pairs which resist hydrolysis and maintain chromosome integrity

Question 18

Which of the following sets of materials are required by both eukaryotes and prokaryotes for replication?

Accepted Answer

A) double-stranded DNA, 4 kinds of dNTPs, primers, origins 
B) topoisomerases, telomerase, polymerases 
C) G-C rich regions, polymerases, chromosome nicks 
D) nucleosome loosening, 4 dNTPs, 4 rNTPs 
E) ligase, primers, nucleases 
A) double-stranded DNA, 4 kinds of dNTPs, primers, origins 
B) topoisomerases, telomerase, polymerases 
C) G-C rich regions, polymerases, chromosome nicks 
D) nucleosome loosening, 4 dNTPs, 4 rNTPs 
E) ligase, primers, nucleases

Question 19

Use Figure 16.1 to answer the following questions.
   
Figure 16.1
-Which enzyme catalyzes the elongation of a DNA strand in the 5' → 3' direction?

Accepted Answer

A) primase 
B) DNA ligase 
C) DNA polymerase III 
D) topoisomerase 
E) helicase 
A) primase 
B) DNA ligase 
C) DNA polymerase III 
D) topoisomerase 
E) helicase

Question 20

Use Figure 16.1 to answer the following questions.
   
Figure 16.1
-The DNA of telomeres has been found to be highly conserved throughout the evolution of eukaryotes. What does this most probably reflect?

Accepted Answer

A) the inactivity of this DNA 
B) the low frequency of mutations occurring in this DNA 
C) that new evolution of telomeres continues 
D) that mutations in telomeres are relatively advantageous 
E) that the critical function of telomeres must be maintained 
A) the inactivity of this DNA 
B) the low frequency of mutations occurring in this DNA 
C) that new evolution of telomeres continues 
D) that mutations in telomeres are relatively advantageous 
E) that the critical function of telomeres must be maintained

Exam 16: The Molecular Basis of Inheritance

Which of the following statements is True of chromatin?

What does transformation involve in bacteria?

Which of the following removes the RNA nucleotides from the primer and adds equivalent DNA nucleotides to the 3' end of Okazaki fragments?

Which of the following best describes the addition of nucleotides to a growing DNA chain?

The leading and the lagging strands differ in that

In analyzing the number of different bases in a DNA sample, which result would be consistent with the base-pairing rules?

Which of the following separates the DNA strands during replication?

What kind of chemical bond is found between paired bases of the DNA double helix?

In a linear eukaryotic chromatin sample, which of the following strands is looped into domains by scaffolding?

Studies of nucleosomes have shown that histones (except H1)exist in each nucleosome as two kinds of tetramers: one of 2 H2A molecules and 2 H2B molecules, and the other as 2 H3 and 2 H4 molecules. Which of the following is supported by this data?

E) coli cells grown on ¹⁵N medium are transferred to ¹⁴N medium and allowed to grow for two more generations (two rounds of DNA replication). DNA extracted from these cells is centrifuged. What density distribution of DNA would you expect in this experiment?

A new DNA strand elongates only in the 5' to 3' direction because

Replication in prokaryotes differs from replication in eukaryotes for which of these reasons?

Which of the following help to hold the DNA strands apart while they are being replicated?

What is the function of DNA polymerase III?

Use Figure 16.1 to answer the following questions. Figure 16.1 -The enzyme telomerase solves the problem of replication at the ends of linear chromosomes by which method?

Which of the following sets of materials are required by both eukaryotes and prokaryotes for replication?

Use Figure 16.1 to answer the following questions. Figure 16.1 -Which enzyme catalyzes the elongation of a DNA strand in the 5' → 3' direction?

Use Figure 16.1 to answer the following questions. Figure 16.1 -The DNA of telomeres has been found to be highly conserved throughout the evolution of eukaryotes. What does this most probably reflect?

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

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal 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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