Question 1

Which of the following can be determined directly from X-ray diffraction photographs of crystallized DNA?

Accepted Answer

A)  the diameter of the helix 
B)  the rate of replication 
C)  the sequence of nucleotides 
D)  the bond angles of the subunits 
E)  the frequency of A vs. T nucleotides 
A)  the diameter of the helix 
B)  the rate of replication 
C)  the sequence of nucleotides 
D)  the bond angles of the subunits 
E)  the frequency of A vs. T nucleotides

Question 2

Polytene chromosomes of Drosophila salivary glands each consist of multiple identical DNA strands that are aligned in parallel arrays. How could these arise?

Accepted Answer

A)  replication followed by mitosis 
B)  replication without separation 
C)  meiosis followed by mitosis 
D)  fertilization by multiple sperm 
E)  special association with histone proteins 
A)  replication followed by mitosis 
B)  replication without separation 
C)  meiosis followed by mitosis 
D)  fertilization by multiple sperm 
E)  special association with histone proteins

Question 3

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

Accepted Answer

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

Question 4

Suppose you are provided with an actively dividing culture of E. coli bacteria to which radioactive thymine has been added. What would happen if a cell replicates once in the presence of this radioactive base?

Accepted Answer

A)  One of the daughter cells, but not the other, would have radioactive DNA. 
B)  Neither of the two daughter cells would be radioactive. 
C)  All four bases of the DNA would be radioactive. 
D)  Radioactive thymine would pair with nonradioactive guanine. 
E)  DNA in both daughter cells would be radioactive. 
A)  One of the daughter cells, but not the other, would have radioactive DNA. 
B)  Neither of the two daughter cells would be radioactive. 
C)  All four bases of the DNA would be radioactive. 
D)  Radioactive thymine would pair with nonradioactive guanine. 
E)  DNA in both daughter cells would be radioactive.

Question 5

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 6

In his work with pneumonia-causing bacteria and mice, Griffith found that

Accepted Answer

A)  the protein coat from pathogenic cells was able to transform nonpathogenic cells. 
B)  heat-killed pathogenic cells caused pneumonia. 
C)  some substance from pathogenic cells was transferred to nonpathogenic cells, making them pathogenic. 
D)  the polysaccharide coat of bacteria caused pneumonia. 
E)  bacteriophages injected DNA into bacteria. 
A)  the protein coat from pathogenic cells was able to transform nonpathogenic cells. 
B)  heat-killed pathogenic cells caused pneumonia. 
C)  some substance from pathogenic cells was transferred to nonpathogenic cells, making them pathogenic. 
D)  the polysaccharide coat of bacteria caused pneumonia. 
E)  bacteriophages injected DNA into bacteria.

Question 7

What is meant by the description "antiparallel" regarding the strands that make up DNA?

Accepted Answer

A)  The twisting nature of DNA creates nonparallel strands. 
B)  The 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand. 
C)  Base pairings create unequal spacing between the two DNA strands. 
D)  One strand is positively charged and the other is negatively charged. 
E)  One strand contains only purines and the other contains only pyrimidines. 
A)  The twisting nature of DNA creates nonparallel strands. 
B)  The 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand. 
C)  Base pairings create unequal spacing between the two DNA strands. 
D)  One strand is positively charged and the other is negatively charged. 
E)  One strand contains only purines and the other contains only pyrimidines.

Question 8

To repair a thymine dimer by nucleotide excision repair, in which order do the necessary enzymes act?

Accepted Answer

A)  exonuclease, DNA polymerase III, RNA primase 
B)  helicase, DNA polymerase I, DNA ligase 
C)  DNA ligase, nuclease, helicase 
D)  DNA polymerase I, DNA polymerase III, DNA ligase 
E)  endonuclease, DNA polymerase I, DNA ligase 
A)  exonuclease, DNA polymerase III, RNA primase 
B)  helicase, DNA polymerase I, DNA ligase 
C)  DNA ligase, nuclease, helicase 
D)  DNA polymerase I, DNA polymerase III, DNA ligase 
E)  endonuclease, DNA polymerase I, DNA ligase

Question 9

What is the role of DNA ligase in the elongation of the lagging strand during DNA replication?

Accepted Answer

A)  It synthesizes RNA nucleotides to make a primer. 
B)  It catalyzes the lengthening of telomeres. 
C)  It joins Okazaki fragments together. 
D)  It unwinds the parental double helix. 
E)  It stabilizes the unwound parental DNA. 
A)  It synthesizes RNA nucleotides to make a primer. 
B)  It catalyzes the lengthening of telomeres. 
C)  It joins Okazaki fragments together. 
D)  It unwinds the parental double helix. 
E)  It stabilizes the unwound parental DNA.

Question 10

You briefly expose bacteria undergoing DNA replication to radioactively labeled nucleotides. When you centrifuge the DNA isolated from the bacteria, the DNA separates into two classes. One class of labeled DNA includes very large molecules (thousands or even millions of nucleotides long), and the other includes short stretches of DNA (several hundred to a few thousand nucleotides in length). These two classes of DNA probably represent

Accepted Answer

A)  leading strands and Okazaki fragments. 
B)  lagging strands and Okazaki fragments. 
C)  Okazaki fragments and RNA primers. 
D)  leading strands and RNA primers. 
E)  RNA primers and mitochondrial DNA. 
A)  leading strands and Okazaki fragments. 
B)  lagging strands and Okazaki fragments. 
C)  Okazaki fragments and RNA primers. 
D)  leading strands and RNA primers. 
E)  RNA primers and mitochondrial DNA.

Question 11

In an analysis of the nucleotide composition of DNA, which of the following will be found?

Accepted Answer

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

Question 12

At a specific area of a chromosome, the sequence of nucleotides below is present where the chain opens to form a replication fork:
3' C C T A G G C T G C A A T C C 5'
An RNA primer is formed starting at the underlined T (T)of the template. Which of the following represents the primer sequence?

Accepted Answer

A)  5' G C C T A G G 3' 
B)  3' G C C T A G G 5' 
C)  5' A C G T T A G G 3' 
D)  5' A C G U U A G G 3' 
E)  5' G C C U A G G 3' 
A)  5' G C C T A G G 3' 
B)  3' G C C T A G G 5' 
C)  5' A C G T T A G G 3' 
D)  5' A C G U U A G G 3' 
E)  5' G C C U A G G 3'

Question 13

Individuals with the disorder xeroderma pigmentosum are hypersensitive to sunlight. This occurs because their cells are impaired in what way?

Accepted Answer

A)  They cannot replicate DNA. 
B)  They cannot undergo mitosis. 
C)  They cannot exchange DNA with other cells. 
D)  They cannot repair thymine dimers. 
E)  They do not recombine homologous chromosomes during meiosis. 
A)  They cannot replicate DNA. 
B)  They cannot undergo mitosis. 
C)  They cannot exchange DNA with other cells. 
D)  They cannot repair thymine dimers. 
E)  They do not recombine homologous chromosomes during meiosis.

Question 14

In a nucleosome, the DNA is wrapped around

Accepted Answer

A)  polymerase molecules. 
B)  ribosomes. 
C)  histones. 
D)  a thymine dimer. 
E)  satellite DNA. 
A)  polymerase molecules. 
B)  ribosomes. 
C)  histones. 
D)  a thymine dimer. 
E)  satellite DNA.

Question 15

Cytosine makes up 42% of the nucleotides in a sample of DNA from an organism. Approximately what percentage of the nucleotides in this sample will be thymine?

Accepted Answer

A)  8% 
B)  16% 
C)  31% 
D)  42% 
E)  It cannot be determined from the information provided. 
A)  8% 
B)  16% 
C)  31% 
D)  42% 
E)  It cannot be determined from the information provided.

Question 16

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

Question 17

Eukaryotic telomeres replicate differently than the rest of the chromosome. This is a consequence of which of the following?

Accepted Answer

A)  the evolution of telomerase enzyme 
B)  DNA polymerase that cannot replicate the leading strand template to its 5' end 
C)  gaps left at the 5' end of the lagging strand 
D)  gaps left at the 3' end of the lagging strand because of the need for a primer 
E)  the "no ends" of a circular chromosome 
A)  the evolution of telomerase enzyme 
B)  DNA polymerase that cannot replicate the leading strand template to its 5' end 
C)  gaps left at the 5' end of the lagging strand 
D)  gaps left at the 3' end of the lagging strand because of the need for a primer 
E)  the "no ends" of a circular chromosome

Exam 16: The Molecular Basis of Inheritance

Which of the following can be determined directly from X-ray diffraction photographs of crystallized DNA?

Polytene chromosomes of Drosophila salivary glands each consist of multiple identical DNA strands that are aligned in parallel arrays. How could these arise?

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

Suppose you are provided with an actively dividing culture of E. coli bacteria to which radioactive thymine has been added. What would happen if a cell replicates once in the presence of this radioactive base?

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

In his work with pneumonia-causing bacteria and mice, Griffith found that

What is meant by the description "antiparallel" regarding the strands that make up DNA?

To repair a thymine dimer by nucleotide excision repair, in which order do the necessary enzymes act?

What is the role of DNA ligase in the elongation of the lagging strand during DNA replication?

In an analysis of the nucleotide composition of DNA, which of the following will be found?

At a specific area of a chromosome, the sequence of nucleotides below is present where the chain opens to form a replication fork: 3' C C T A G G C T G C A A T C C 5' An RNA primer is formed starting at the underlined T (T)of the template. Which of the following represents the primer sequence?

Individuals with the disorder xeroderma pigmentosum are hypersensitive to sunlight. This occurs because their cells are impaired in what way?

In a nucleosome, the DNA is wrapped around

Cytosine makes up 42% of the nucleotides in a sample of DNA from an organism. Approximately what percentage of the nucleotides in this sample will be thymine?

The DNA of telomeres has been found to be highly conserved throughout the evolution of eukaryotes. What does this most probably reflect?

Eukaryotic telomeres replicate differently than the rest of the chromosome. This is a consequence of which of the following?

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

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal 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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