Question 1

In E.coli,________ helps regulate the frequency of DNA replication.

Accepted Answer

A) DnaA 
B) DnaB 
C) Tus 
D) RecA 
A) DnaA 
B) DnaB 
C) Tus 
D) RecA A

Question 2

Why is only one copy of DNA made per cell division cycle in eukaryotes despite the presence of multiple origins of replication?

Accepted Answer

A) There is only one origin of replication per chromosome. 
B) The rate of elongation proceeds at a rate that allows only one copy to be made by the time the cell divides. 
C) The activity of an S-phase protein kinase controls the formation of the pre-replication complex. 
D) Primase is activated by phosphorylation only at the onset of S-phase by S-phase protein kinase. 
A) There is only one origin of replication per chromosome. 
B) The rate of elongation proceeds at a rate that allows only one copy to be made by the time the cell divides. 
C) The activity of an S-phase protein kinase controls the formation of the pre-replication complex. 
D) Primase is activated by phosphorylation only at the onset of S-phase by S-phase protein kinase. C

Question 3

Functions of DNA polymerases and accessory proteins in eukaryotic DNA replication include

Accepted Answer

A) PCNA protein,a sliding clamp unit for DNA. 
B) β- DNA polymerase,for repair of damaged DNA. 
C) RPA protein,and equivalent of SSB proteins in bacteria. 
D) RPC protein,used for mitochondrial DNA synthesis. 
E) All of the above. 
A) PCNA protein,a sliding clamp unit for DNA. 
B) β- DNA polymerase,for repair of damaged DNA. 
C) RPA protein,and equivalent of SSB proteins in bacteria. 
D) RPC protein,used for mitochondrial DNA synthesis. 
E) All of the above. E

Question 4

There are more replication forks during replication of eukaryotic DNA than prokaryotic DNA.

Accepted Answer

A) True 
 B)False

Question 5

Which is not a common type of DNA damage (lesion)?

Accepted Answer

A) Pyrimidine dimers. 
B) Cross-linking of DNA strands. 
C) Alkylation of bases. 
D) Deamination of thymines. 
A) Pyrimidine dimers. 
B) Cross-linking of DNA strands. 
C) Alkylation of bases. 
D) Deamination of thymines.

Question 6

Proteins bind to both origin sites and termination sites on DNA during DNA replication.

Accepted Answer

A) True 
 B)False

Question 7

Enzymes that remain bound to their nascent chains through many polymerization steps are said to be ________.

Accepted Answer

A) constitutive 
B) distributive 
C) conjugated 
D) processive 
A) constitutive 
B) distributive 
C) conjugated 
D) processive

Question 8

In a sequencing gel,all fragment in one of the four lanes terminates in the same type of nucleotide base.

Accepted Answer

A) True 
 B)False

Question 9

What is the function of the primosome?

Accepted Answer

A) Removal of RNA from the lagging strand. 
B) Synthesis of short RNA fragments. 
C) Assembly of DNA polymerase III holoenzyme. 
D) Detection of the origin of replication. 
A) Removal of RNA from the lagging strand. 
B) Synthesis of short RNA fragments. 
C) Assembly of DNA polymerase III holoenzyme. 
D) Detection of the origin of replication.

Question 10

DNA polymerase I possesses 5' → 3' exonuclease activity.

Accepted Answer

A) True 
 B)False

Question 11

Prokaryotic DNA replication occurs in two steps.First,ATP provides a phosphate to the growing DNA chain.This is followed by addition of a nucleoside.

Accepted Answer

A) True 
 B)False

Question 12

In the Holliday model describing recombination

Accepted Answer

A) homologous sequences line up. 
B) strands of DNA are nicked. 
C) DNA strands associate with the homologous strand ("strand invasion"). 
D) strands rotate then are cleaved at the crossover point. 
E) All of the above. 
A) homologous sequences line up. 
B) strands of DNA are nicked. 
C) DNA strands associate with the homologous strand ("strand invasion"). 
D) strands rotate then are cleaved at the crossover point. 
E) All of the above.

Question 13

Since the rate of fork movement in eukaryotes is much slower than that of bacteria,chromosomes require more than an hour to replicate.

Accepted Answer

A) True 
 B)False

Question 14

RNA primers are synthesized about once every ________.

Accepted Answer

A) millisecond 
B) second 
C) minute 
D) 40 minutes 
A) millisecond 
B) second 
C) minute 
D) 40 minutes

Question 15

The reaction catalyzed by DNA photolyase is an example of what type of repair?

Accepted Answer

A) Recombination. 
B) Excision. 
C) Mismatch. 
D) Direct. 
A) Recombination. 
B) Excision. 
C) Mismatch. 
D) Direct.

Question 16

Sanger DNA sequencing requires inhibition of DNA polymerization by a specific dideoxynucleoside every time it is copied in the replication process.

Accepted Answer

A) True 
 B)False

Question 17

Although histones and DNA are made in the same parts of the eukaryotic cell,the packaging of them in the nucleosome slows down replication so that it is slower than that of prokaryotes.

Accepted Answer

A) True 
 B)False

Question 18

Eukaryotic cells contain at least five DNA polymerases all of which are responsible for nuclear DNA replication.

Accepted Answer

A) True 
 B)False

Question 19

The beta subunits of E.coli DNA polymerase III are responsible for its ________.

Accepted Answer

A) 5'→ 3' polymerase 
B) sliding clamp 
C) 3' → 5' exonuclease and proof-reading 
D) ribosome assembly 
A) 5'→ 3' polymerase 
B) sliding clamp 
C) 3' → 5' exonuclease and proof-reading 
D) ribosome assembly

Question 20

Deaminated bases must be removed from DNA because

Accepted Answer

A) they distort the molecule. 
B) they form thymine dimers. 
C) they pair incorrectly during replication. 
D) the mRNA formed may be irregular. 
A) they distort the molecule. 
B) they form thymine dimers. 
C) they pair incorrectly during replication. 
D) the mRNA formed may be irregular.

Exam 20: DNA Replication, repair, and Recombination

In E.coli,________ helps regulate the frequency of DNA replication.

Why is only one copy of DNA made per cell division cycle in eukaryotes despite the presence of multiple origins of replication?

Functions of DNA polymerases and accessory proteins in eukaryotic DNA replication include

There are more replication forks during replication of eukaryotic DNA than prokaryotic DNA.

Which is not a common type of DNA damage (lesion)?

Proteins bind to both origin sites and termination sites on DNA during DNA replication.

Enzymes that remain bound to their nascent chains through many polymerization steps are said to be ________.

In a sequencing gel,all fragment in one of the four lanes terminates in the same type of nucleotide base.

What is the function of the primosome?

DNA polymerase I possesses 5' → 3' exonuclease activity.

Prokaryotic DNA replication occurs in two steps.First,ATP provides a phosphate to the growing DNA chain.This is followed by addition of a nucleoside.

In the Holliday model describing recombination

Since the rate of fork movement in eukaryotes is much slower than that of bacteria,chromosomes require more than an hour to replicate.

RNA primers are synthesized about once every ________.

The reaction catalyzed by DNA photolyase is an example of what type of repair?

Sanger DNA sequencing requires inhibition of DNA polymerization by a specific dideoxynucleoside every time it is copied in the replication process.

Although histones and DNA are made in the same parts of the eukaryotic cell,the packaging of them in the nucleosome slows down replication so that it is slower than that of prokaryotes.

Eukaryotic cells contain at least five DNA polymerases all of which are responsible for nuclear DNA replication.

The beta subunits of E.coli DNA polymerase III are responsible for its ________.

Deaminated bases must be removed from DNA because

Introduction to Biochemistry

Water

Amino Acids and the Primary Structures of Proteins

Proteins: Three-Dimensional Structure and Function

Properties of Enzymes

Mechanisms of Enzymes

Coenzymes and Vitamins

Carbohydrates

Lipids and Membranes

Introduction to Metabolism

Glycolysis

Gluconeogenesis, the Pentose Phosphate Pathway, and Glycogen Metabolism

The Citric Acid Cycle

Electron Transport and Atp Synthesis

Photosynthesis

Lipid Metabolism

Amino Acid Metabolism

Nucleotide Metabolism

Nucleic Acids

Transcription and RNA Processing

Protein Synthesis

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