Question 1

Which of the following best describes the double-helix of DNA?

Accepted Answer

A)  It has directionality 
B)  The strands are arranged in an anti-parallel arrangement 
C)  The strands are complementary 
D)  All of the answers are correct 
A)  It has directionality 
B)  The strands are arranged in an anti-parallel arrangement 
C)  The strands are complementary 
D)  All of the answers are correct D

Question 2

What is the name for the mechanism of DNA replication in which one parental strand and one daughter strand are combined following replication?

Accepted Answer

A)  Dispersive 
B)  Semiconservative 
C)  Conservative 
D)  All of the answers are correct 
A)  Dispersive 
B)  Semiconservative 
C)  Conservative 
D)  All of the answers are correct B

Question 3

You have isolated what appears to be alien DNA. While studying its replication, you performed the exact experiment Meselson and Stahl did. After three generations, the DNA is subjected to a CsCl gradient and only one band appears. What type of replication does this DNA undergo?

Accepted Answer

A)  Semiconservative 
B)  Conservative 
C)  Dispersive 
A)  Semiconservative 
B)  Conservative 
C)  Dispersive C

Question 4

What types of mutants were essential to the discovery of new replication enzymes?

Accepted Answer

A)  Gain-of-function mutations 
B)  Lethal mutations 
C)  Temperature-sensitive mutations 
D)  None of the answers are correct 
A)  Gain-of-function mutations 
B)  Lethal mutations 
C)  Temperature-sensitive mutations 
D)  None of the answers are correct

Question 5

The ability of the DNA polymerase to remove mismatched bases is called exonuclease cleavage (proofreading).

Accepted Answer

A) True 
 B)False

Question 6

DNA helicase enzymes move in what direction along the DNA during DNA replication?

Accepted Answer

A)  5' to 3' 
B)  3' to 5' 
C)  They remain stationary 
A)  5' to 3' 
B)  3' to 5' 
C)  They remain stationary

Question 7

Manufactures a 10-12 base segment of RNA.

Accepted Answer

A)  DNA ligase 
B)  Primase 
C)  Topoisomerase 
D)  DNA polymerase I 
E)  DNA polymerase III 
A)  DNA ligase 
B)  Primase 
C)  Topoisomerase 
D)  DNA polymerase I 
E)  DNA polymerase III

Question 8

Which of the following stops the replication of DNA in prokaryotes?

Accepted Answer

A)  Tus proteins 
B)  DNA ligase 
C)  Okazaki fragments 
D)  The end of the chromosome 
A)  Tus proteins 
B)  DNA ligase 
C)  Okazaki fragments 
D)  The end of the chromosome

Question 9

After the action of the helicase, single-stranded binding proteins keep the parental DNA strands from reforming a double-helix.

Accepted Answer

A) True 
 B)False

Question 10

You are performing a biochemical purification of enzymes involved in DNA replication. You have purified the replisome. You wish to purify the primosome. You perform further separation techniques on your purified replisome. How will you test to determine that you have purified the primosome?

Accepted Answer

A)  You should confirm that your sample has helicase and primase activity, but not the ability to synthesize DNA. 
B)  You should confirm that your sample has the ability to synthesize DNA and has primase activity, but no helicase activity. 
C)  You should confirm that your sample has helicase and primase activity. This is the only test that is needed. 
D)  You should confirm that your sample has primase activity and can synthesize DNA. This is the only test that is needed. 
A)  You should confirm that your sample has helicase and primase activity, but not the ability to synthesize DNA. 
B)  You should confirm that your sample has the ability to synthesize DNA and has primase activity, but no helicase activity. 
C)  You should confirm that your sample has helicase and primase activity. This is the only test that is needed. 
D)  You should confirm that your sample has primase activity and can synthesize DNA. This is the only test that is needed.

Question 11

Responsible for the majority of DNA replication.

Accepted Answer

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

Question 12

Catenanes can only form in cells with circular chromosomes, such as bacteria.

Accepted Answer

A) True 
 B)False

Question 13

The Meselson-Stahl experiments supported the model of dispersive DNA replication.

Accepted Answer

A) True 
 B)False

Question 14

How many DNA polymerases are found in prokaryotes?

Accepted Answer

A)  5 
B)  7 
C)  9 
D)  12 
A)  5 
B)  7 
C)  9 
D)  12

Question 15

The proofreading of newly synthesized DNA by DNA Pol III occurs in the ________.

Accepted Answer

A)  5' to 3' direction 
B)  3' to 5' direction 
C)  Both directions 
A)  5' to 3' direction 
B)  3' to 5' direction 
C)  Both directions

Question 16

The problem in synthesizing the 3' end of chromosomes is solved by the use of the telomerase enzyme.

Accepted Answer

A) True 
 B)False

Question 17

You are in the lab trying to synthesize DNA in vitro. You are upset because the lab seems to be out of dNTPs (deoxynucleoside triphosphates) but you find a tube of dNMPs (deoxynucleoside monophosphates) in the freezer. You add this to your replication reaction instead of dNTPs. Will your reaction work? Why or why not?

Accepted Answer

A)  No, cleavage of dNTP drives the formation of the covalent bond between the nucleoside monophosphate and the growing DNA strand. 
B)  Yes, only the nucleoside monophosphate ultimately is incorporated into the growing DNA strand. 
C)  No, all three phosphates on the nucleoside triphosphate are incorporated into the growing DNA strand. 
D)  Yes, the formation of the covalent bond between the nucleoside monophosphate and the growing DNA strand is energetically favorable. 
A)  No, cleavage of dNTP drives the formation of the covalent bond between the nucleoside monophosphate and the growing DNA strand. 
B)  Yes, only the nucleoside monophosphate ultimately is incorporated into the growing DNA strand. 
C)  No, all three phosphates on the nucleoside triphosphate are incorporated into the growing DNA strand. 
D)  Yes, the formation of the covalent bond between the nucleoside monophosphate and the growing DNA strand is energetically favorable.

Question 18

Which of the following best describes the mechanism of DNA replication in which both parental strands remain together following replication?

Accepted Answer

A)  Dispersive 
B)  Semiconservative 
C)  Conservative 
D)  All of the answers are correct 
A)  Dispersive 
B)  Semiconservative 
C)  Conservative 
D)  All of the answers are correct

Question 19

DNA polymerase is a primer-dependent enzyme that functions only in the 5'-3' direction. These are the two most fundamental concepts to understanding this enzyme. Based on this, which of the following enzyme pairs are analogous in prokaryotes and eukaryotes?

Accepted Answer

A)  DNA pol I : DNA pol α 
B)  DNA pol II : DNA pol β 
C)  DNA pol III : DNA pol δ 
D)  All of the answers are correct 
A)  DNA pol I : DNA pol α 
B)  DNA pol II : DNA pol β 
C)  DNA pol III : DNA pol δ 
D)  All of the answers are correct

Question 20

A primosome consists of a polymerase and a single-stranded binding protein.

Accepted Answer

A) True 
 B)False

Exam 11: Dna Replication

Which of the following best describes the double-helix of DNA?

What is the name for the mechanism of DNA replication in which one parental strand and one daughter strand are combined following replication?

You have isolated what appears to be alien DNA. While studying its replication, you performed the exact experiment Meselson and Stahl did. After three generations, the DNA is subjected to a CsCl gradient and only one band appears. What type of replication does this DNA undergo?

What types of mutants were essential to the discovery of new replication enzymes?

The ability of the DNA polymerase to remove mismatched bases is called exonuclease cleavage (proofreading).

DNA helicase enzymes move in what direction along the DNA during DNA replication?

Manufactures a 10-12 base segment of RNA.

Which of the following stops the replication of DNA in prokaryotes?

After the action of the helicase, single-stranded binding proteins keep the parental DNA strands from reforming a double-helix.

You are performing a biochemical purification of enzymes involved in DNA replication. You have purified the replisome. You wish to purify the primosome. You perform further separation techniques on your purified replisome. How will you test to determine that you have purified the primosome?

Responsible for the majority of DNA replication.

Catenanes can only form in cells with circular chromosomes, such as bacteria.

The Meselson-Stahl experiments supported the model of dispersive DNA replication.

How many DNA polymerases are found in prokaryotes?

The proofreading of newly synthesized DNA by DNA Pol III occurs in the ________.

The problem in synthesizing the 3' end of chromosomes is solved by the use of the telomerase enzyme.

Which of the following best describes the mechanism of DNA replication in which both parental strands remain together following replication?

DNA polymerase is a primer-dependent enzyme that functions only in the 5'-3' direction. These are the two most fundamental concepts to understanding this enzyme. Based on this, which of the following enzyme pairs are analogous in prokaryotes and eukaryotes?

A primosome consists of a polymerase and a single-stranded binding protein.

Overview of Genetics

Mendelian Inheritance

Chromosome Transmission During Cell Division and Sexual Reproduction

Extensions of Mendelian Inheritance

Non-Mendelian Inheritance

Genetic Linkage and Mapping in Eukaryotes

Genetic Transfer and Mapping in Bacteria

Variation in Chromosome Structure and Number

Molecular Structure of Dna and Rna

Chromosome Organization and Molecular Structure

Gene Transcription and Rna Modification

Translation of Mrna

Gene Regulation in Bacteria

Gene Regulation in Eukaryotes I: Transcriptional and Translation Regulation

Gene Regulation in Eukaryotes Ii: Epigenetics

Non-Coding Rnas

Genetics of Viruses

Gene Mutation and Dna Repair

Recombination, Immunogenetics, and Transposition

Molecular Technologies

Biotechnology

Genomics I: Analysis of Dna

Genomics Ii: Functional Genomics, Proteomics, and Bioinformatics

Medical Genetics and Cancer

Developmental Genetics

Population Genetics

Complex and Quantitative Traits

Evolutionary Genetics

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