Question 1

The enzymatic activity of a telomerase is best described as a

Accepted Answer

A)  polymerase. 
B)  reverse transcriptase. 
C)  exonuclease. 
D)  ligase. 
E)  topoisomerase. 
A)  polymerase. 
B)  reverse transcriptase. 
C)  exonuclease. 
D)  ligase. 
E)  topoisomerase. B

Question 2

DNA primase is an enzyme that catalyzes the reaction necessary to synthesize a molecule of DNA.

Accepted Answer

A) True 
 B)False  False

Question 3

What are the key replication enzymes at the replisome, and how is DNA replication on both leading and lagging strands made efficient through the conformation of the DNA at the replisome?

Accepted Answer

The key replication enzymes at the replisome are helicase, primase, and DNA polymerase III. To make replication more efficient, the lagging-strand DNA is folded so that its DNA polymerase III is complexed with the DNA polymerase III on the leading strand (forming the DNA Pol III holoenzyme). The folding of the lagging-strand template also makes production of sequential Okazaki fragments more efficient by bringing the 3' end of each completed Okazaki fragments near the site where the next Okazaki fragment will start.

Question 4

Which enzyme activity is associated with DNA polymerase I?

Accepted Answer

A)  5' to 3' polymerase 
B)  3' to 5' exonuclease 
C)  5' to 3' exonuclease 
D)  Both A and B 
E)  All of the above 
A)  5' to 3' polymerase 
B)  3' to 5' exonuclease 
C)  5' to 3' exonuclease 
D)  Both A and B 
E)  All of the above

Question 5

In both prokaryotes and eukaryotes, DNA replication is

Accepted Answer

A)  bidirectional and semiconservative. 
B)  bidirectional and dispersive. 
C)  unidirectional and dispersive. 
D)  dispersive and semiconservative. 
E)  unidirectional and semiconservative. 
A)  bidirectional and semiconservative. 
B)  bidirectional and dispersive. 
C)  unidirectional and dispersive. 
D)  dispersive and semiconservative. 
E)  unidirectional and semiconservative.

Question 6

Only the leading strand of a DNA molecule serves as a template during replication.

Accepted Answer

A) True 
 B)False

Question 7

Topoisomerase and SSB proteins are important components of the replication process in prokaryotes, but they are not found in eukaryotes.

Accepted Answer

A) True 
 B)False

Question 8

In eukaryotes, DNA replication begins at a single origin of replication on each chromosome.

Accepted Answer

A) True 
 B)False

Question 9

Where does the initiator protein bind DNA at the start of replication?

Accepted Answer

A)  At a replication fork 
B)  At an origin of replication 
C)  At a promoter region 
D)  At a start codon 
E)  At any AT-rich region 
A)  At a replication fork 
B)  At an origin of replication 
C)  At a promoter region 
D)  At a start codon 
E)  At any AT-rich region

Question 10

After removal of the RNA primers and replacement with DNA nucleotides, the single-stranded nick adjacent to Okazaki fragments is filled in through a reaction that involves which enzyme?

Accepted Answer

A)  DNA ligase 
B)  SSB protein 
C)  DNA primase 
D)  RNA polymerase 
E)  DNA helicase 
A)  DNA ligase 
B)  SSB protein 
C)  DNA primase 
D)  RNA polymerase 
E)  DNA helicase

Question 11

In eukaryotic cells, RNA and proteins are actively synthesized during the S phase of the cell cycle.

Accepted Answer

A) True 
 B)False

Question 12

When the RNA primers are removed from the 5' ends of eukaryotic chromosomes after replication, DNA polymerase is unable to fill in the gaps. What prevents the chromosomes from getting shorter and shorter with each round of replication?

Accepted Answer

The enzyme telomerase maintains chromoso

Question 13

Which of the following are necessary for DNA replication in vitro?

Accepted Answer

A)  DNA can't replicate in vitro 
B)  Okazaki fragments, helicase, DNA polymerase 
C)  RNA, helicase, DNA polymerase 
D)  Template DNA, DNA polymerase, four dNTPs, magnesium ions 
E)  Template DNA, four dNTPs, and magnesium ions 
A)  DNA can't replicate in vitro 
B)  Okazaki fragments, helicase, DNA polymerase 
C)  RNA, helicase, DNA polymerase 
D)  Template DNA, DNA polymerase, four dNTPs, magnesium ions 
E)  Template DNA, four dNTPs, and magnesium ions

Question 14

Which enzyme elongates the new DNA strand starting at an RNA primer?

Accepted Answer

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

Question 15

At the growing end of a DNA chain, DNA polymerase catalyzes the formation of a disulfide bond between the 3'-OH group of the deoxyribose on the last nucleotide and the 5'-phosphate of the dNTP precursor.

Accepted Answer

A) True 
 B)False

Question 16

Which kind of enzyme prevents DNA from tangling up by introducing negative supercoils as the replication fork migrates during replication?

Accepted Answer

A)  Helicase 
B)  DNA polymerase I 
C)  Topoisomerase 
D)  DNA polymerase III 
E)  Ligase 
A)  Helicase 
B)  DNA polymerase I 
C)  Topoisomerase 
D)  DNA polymerase III 
E)  Ligase

Question 17

The two most basic steps of DNA replication are

Accepted Answer

A)  the new strand is denatured and a template is synthesized. 
B)  helicase unwinds template and DNA polymerase binds. 
C)  primase causes primer to bind template and ligase copies the template. 
D)  the template is denatured and a new strand is synthesized. 
E)  leading strand is copied first and lagging strand second. 
A)  the new strand is denatured and a template is synthesized. 
B)  helicase unwinds template and DNA polymerase binds. 
C)  primase causes primer to bind template and ligase copies the template. 
D)  the template is denatured and a new strand is synthesized. 
E)  leading strand is copied first and lagging strand second.

Question 18

What is a method by which you could visualize semiconservative DNA replication in eukaryotes?

Accepted Answer

You could use chromosomal staining in ce

Question 19

As helicase unwinds the DNA molecule, what keeps the strands apart?

Accepted Answer

A)  Replication fork 
B)  Okazaki fragments 
C)  DNA polymerase 
D)  Reverse transcriptase 
E)  Single-strand binding proteins 
A)  Replication fork 
B)  Okazaki fragments 
C)  DNA polymerase 
D)  Reverse transcriptase 
E)  Single-strand binding proteins

Question 20

The diploid set of chromosomes in Drosophila embryos replicates six times faster than the single E. coli chromosome, even though there is about 100 times more DNA in Drosophila than in E. coli and the rate of movement of the replication fork in Drosophila is much slower. How is this so?

Accepted Answer

Eukaryotic chromosomes duplicate rapidly

Exam 10: Non-Mendelian Inheritance

The enzymatic activity of a telomerase is best described as a

DNA primase is an enzyme that catalyzes the reaction necessary to synthesize a molecule of DNA.

What are the key replication enzymes at the replisome, and how is DNA replication on both leading and lagging strands made efficient through the conformation of the DNA at the replisome?

Which enzyme activity is associated with DNA polymerase I?

In both prokaryotes and eukaryotes, DNA replication is

Only the leading strand of a DNA molecule serves as a template during replication.

Topoisomerase and SSB proteins are important components of the replication process in prokaryotes, but they are not found in eukaryotes.

In eukaryotes, DNA replication begins at a single origin of replication on each chromosome.

Where does the initiator protein bind DNA at the start of replication?

After removal of the RNA primers and replacement with DNA nucleotides, the single-stranded nick adjacent to Okazaki fragments is filled in through a reaction that involves which enzyme?

In eukaryotic cells, RNA and proteins are actively synthesized during the S phase of the cell cycle.

When the RNA primers are removed from the 5' ends of eukaryotic chromosomes after replication, DNA polymerase is unable to fill in the gaps. What prevents the chromosomes from getting shorter and shorter with each round of replication?

Which of the following are necessary for DNA replication in vitro?

Which enzyme elongates the new DNA strand starting at an RNA primer?

At the growing end of a DNA chain, DNA polymerase catalyzes the formation of a disulfide bond between the 3'-OH group of the deoxyribose on the last nucleotide and the 5'-phosphate of the dNTP precursor.

Which kind of enzyme prevents DNA from tangling up by introducing negative supercoils as the replication fork migrates during replication?

The two most basic steps of DNA replication are

What is a method by which you could visualize semiconservative DNA replication in eukaryotes?

As helicase unwinds the DNA molecule, what keeps the strands apart?

The diploid set of chromosomes in Drosophila embryos replicates six times faster than the single E. coli chromosome, even though there is about 100 times more DNA in Drosophila than in E. coli and the rate of movement of the replication fork in Drosophila is much slower. How is this so?

Genetics of Bacteria and Bacteriophages

Variations in Chromosome Structure and Number

Advanced Gene Mapping in Eukaryotes

Gene Mapping in Eukaryotes

Quantitative Genetics

Extensions of Mendelian Genetic Principles

Chromosomal Basis of Inheritance

Molecular Evolution

Population Genetics

Genetics of Cancer

Genetic Analysis of Development

Regulation of Gene Expression in Eukaryotes

Mendelian Genetics

Regulation of Gene Expression in Bacteria and Bacteriophages

Genomics

Applications of Recombinant DNA Technology

Recombinant DNA Technology

DNA Mutation, DNA Repair, and Transposable Elements

Gene Expression: Translation

Gene Expression: Transcription

Gene Control of Proteins

DNA Replication

DNA: The Genetic Material

Genetics: an Introduction

Filters