Question 1

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.F) All of the above
G) B) and C)

Question 2

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.F) A) and D)
G) A) and C)

Question 3

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'F) A) and D)
G) B) and E)

Question 4

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 chromosomeF) A) and D)
G) A) and C)

Question 5

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.F) C) and D)
G) A) and C)

Question 6

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.F) A) and B)
G) D) and E)

Question 7

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.F) B) and C)
G) A) and E)

Question 8

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 maintainedF) B) and D)
G) B) and C)

Question 9

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 ligaseF) All of the above
G) D) and E)

Question 10

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 nucleotidesF) B) and D)
G) A) and E)

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 + AE) B) and C)
F) A) and B)

Question 12

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, nucleasesF) A) and B)
G) B) and D)

Question 13

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.F) None of the above
G) B) and D)

Question 14

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 proteinsF) A) and B)
G) A) and C)

Question 15

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.F) B) and D)
G) A) and B)

Question 16

In a nucleosome, the DNA is wrapped around

Accepted Answer

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

Question 17

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.F) D) and E)
G) B) and D)

Exam 16: The Molecular Basis of Inheritance

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

Correct Answer
verified

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

Correct Answer
verified

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

Correct Answer
verified

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

Correct Answer
verified

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

Correct Answer
verified

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?

Correct Answer
verified

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?

Correct Answer
verified

Correct Answer
verified

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

Correct Answer
verified

In a nucleosome, the DNA is wrapped around

Correct Answer
verified

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

Correct Answer
verified

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

Correct Answer
verified

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

Correct Answer
verified

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?

Correct Answer
verified

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

Correct Answer
verified

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

Correct Answer
verified

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

Correct Answer
verified

Exam 16: The Molecular Basis of Inheritance

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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?

Correct AnswerverifiedShow Answer

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?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

In a nucleosome, the DNA is wrapped around

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Correct Answer
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