Question 1

Pol I synthesizes new DNA with very high fidelity,due to its

Accepted Answer

A) high processivity. 
B) 3'  $\to$ 5'exonuclease activity.  
C) helicase association with the primase. 
D) 5'  $\to$ 3' exonuclease activity. 
E) all of the above. 
A) high processivity. 
B) 3'  $\to$ 5'exonuclease activity.  
C) helicase association with the primase. 
D) 5'  $\to$ 3' exonuclease activity. 
E) all of the above. B

Question 2

The DNA sequence shown below is copied by the Klenow fragment.Which of the following would most likely result?
5' TGCGTGCACTCGA 3'

Accepted Answer

A) identical 
B) 5' TGCGT 3' 
C) 5' TGCAGTGACGCT 3' 
D) cannot predict 
E) none of the above 
A) identical 
B) 5' TGCGT 3' 
C) 5' TGCAGTGACGCT 3' 
D) cannot predict 
E) none of the above C

Question 3

Capping is important because

Accepted Answer

A) it likely protects the telomere ends from becoming shortened. 
B) it likely prevents DNA repair mechanisms from initiating at the telomeres. 
C) it likely results in increased processivity on the eukaryotic chromosome. 
D) all of the above 
E) none of the above 
A) it likely protects the telomere ends from becoming shortened. 
B) it likely prevents DNA repair mechanisms from initiating at the telomeres. 
C) it likely results in increased processivity on the eukaryotic chromosome. 
D) all of the above 
E) none of the above B

Question 4

Which of the following statements about Pol I is FALSE?

Accepted Answer

A) Experiments demonstrate that Pol I exhibits exonuclease activity. 
B) Pol I is not the primary replicase in E.coli. 
C) Mutation analysis demonstrates that Pol I functions in DNA repair. 
D) Mutation analysis demonstrates the Pol I activity is not essential for cell viability. 
E) Experiments have successfully utilized Pol I to radioactively label DNA in lab experiments. 
A) Experiments demonstrate that Pol I exhibits exonuclease activity. 
B) Pol I is not the primary replicase in E.coli. 
C) Mutation analysis demonstrates that Pol I functions in DNA repair. 
D) Mutation analysis demonstrates the Pol I activity is not essential for cell viability. 
E) Experiments have successfully utilized Pol I to radioactively label DNA in lab experiments.

Question 5

DNA ligase can be activated by which of the following?
(I)The coupled hydrolysis of NAD+ to (NMN+)+ AMP.
(II)The coupled hydrolysis of ATP to AMP + PPi.
(III)The coupled hydrolysis of GTP to GMP + PPi.

Accepted Answer

A) I only 
B) II only 
C) III only 
D) I,II 
E) I,III 
A) I only 
B) II only 
C) III only 
D) I,II 
E) I,III

Question 6

Which of the following describes the Holliday junction?

Accepted Answer

A) point where DNA base excision repair initiates 
B) crossover point involving 4-stranded DNA structure in homologous recombination 
C) insertion point of a gene flanked in transposons 
D) point where MutS binds to initiate SOS response 
E) none of the above 
A) point where DNA base excision repair initiates 
B) crossover point involving 4-stranded DNA structure in homologous recombination 
C) insertion point of a gene flanked in transposons 
D) point where MutS binds to initiate SOS response 
E) none of the above

Question 7

Which of the following can be extended by DNA polymerase?

Accepted Answer

A) a single strand of DNA ending in a nucleotide with a free 3' OH 
B) a RNA single strand with a ribonucleotide with a free 3' OH 
C) a single strand DNA end in a deoxyribonucleotide with free 5' P 
D) a RNA single strand 
E) all of the above 
A) a single strand of DNA ending in a nucleotide with a free 3' OH 
B) a RNA single strand with a ribonucleotide with a free 3' OH 
C) a single strand DNA end in a deoxyribonucleotide with free 5' P 
D) a RNA single strand 
E) all of the above

Question 8

Matching
Choose the correct answer from the list.Not all the answers will be used.

-Enzymes that undergo many rounds of polymerization catalysis before dissociating from the substrate are described as highly ______.

Accepted Answer

A)  SSB 
B)  Tus 
C)  primosome 
D)  ARS 
E)  ATS
F) primer
G) transposons
H) nick translation
I) photolyase
J) processive
K) G-loops
L) G-quartets
M) accurate
N) lagging strand synthesis
O) MCM
P) abortive 
A)  SSB 
B)  Tus 
C)  primosome 
D)  ARS 
E)  ATS
F) primer
G) transposons
H) nick translation
I) photolyase
J) processive
K) G-loops
L) G-quartets
M) accurate
N) lagging strand synthesis
O) MCM
P) abortive

Question 9

Which of the following activities does E.coli DNA polymerase III contain?
(I)5'→3' polymerase
(II)5'→3' exonuclease
(III)3'→5' exonuclease

Accepted Answer

A) I only 
B) I,II 
C) II only 
D) I,III 
E) I,II,III 
A) I only 
B) I,II 
C) II only 
D) I,III 
E) I,II,III

Question 10

Use the following diagram to complete the sentences below
 
" ______ is the enzyme which catalyzes phosphodiester bond formation on both strands.Processivity of DNA pol is increased when associated with ____.DNA untwisting is accomplished by ______."

Accepted Answer

A) A,C,B 
B) A,B,C 
C) B,C,A 
D) A,D,B 
E) A,E,B 
A) A,C,B 
B) A,B,C 
C) B,C,A 
D) A,D,B 
E) A,E,B

Question 11

Which of the following enzymes catalyze the creation of AP sites for base excision repair?

Accepted Answer

A) exonuclease 
B) endonuclease 
C) ligase 
D) glycosylase 
E) methylase 
A) exonuclease 
B) endonuclease 
C) ligase 
D) glycosylase 
E) methylase

Question 12

Suppose Meselson & Stahl had observed the following data in their famous experiment involving a switch from medium containing 15N to 14N.What would they have concluded about the nature of DNA replication?

Accepted Answer

A) They still would have concluded that DNA replication is semiconservative. 
B) They would have concluded that DNA replication is conservative. 
C) They would have concluded that DNA replication is dispersive/random. 
D) None of the above is correct. 
E) Cannot be determined with the information given. 
A) They still would have concluded that DNA replication is semiconservative. 
B) They would have concluded that DNA replication is conservative. 
C) They would have concluded that DNA replication is dispersive/random. 
D) None of the above is correct. 
E) Cannot be determined with the information given.

Question 13

Which of the following describes the usefulness of primase?

Accepted Answer

A) It removes RNA bases and replaces them with DNA bases. 
B) It seals nicks. 
C) It adds an RNA starter sequence which can be elongated. 
D) It is only required on the leading strand. 
E) It unwinds the DNA. 
A) It removes RNA bases and replaces them with DNA bases. 
B) It seals nicks. 
C) It adds an RNA starter sequence which can be elongated. 
D) It is only required on the leading strand. 
E) It unwinds the DNA.

Question 14

A prokaryotic replisome typically contains two molecules of DNA pol III,but only one molecule of DNA pol I.Why?

Accepted Answer

A) The DNA pol I works on the leading strand,while DNA pol IIIs work on the Okazaki fragments.since there are several of those,it takes more proteins to keep up. 
B) DNA pol I has a built-in proofreading exonuclease;DNA pol III does not.The second DNA pol III is needed to follow the first to accomplish the necessary proofreading. 
C) The DNA pol IIIs work at one replication fork,while the DNA pol I works at the other.This way they don't meet exactly at the other side of the chromosome. 
D) The DNA pol IIIs do most of the work.DNA pol I only has to work on the telomers. 
E) DNA pol I replaces the RNA primers with DNA,which really only needs to be done repetitively on one strand,while both strands are worked on by the DNA pol IIIs. 
A) The DNA pol I works on the leading strand,while DNA pol IIIs work on the Okazaki fragments.since there are several of those,it takes more proteins to keep up. 
B) DNA pol I has a built-in proofreading exonuclease;DNA pol III does not.The second DNA pol III is needed to follow the first to accomplish the necessary proofreading. 
C) The DNA pol IIIs work at one replication fork,while the DNA pol I works at the other.This way they don't meet exactly at the other side of the chromosome. 
D) The DNA pol IIIs do most of the work.DNA pol I only has to work on the telomers. 
E) DNA pol I replaces the RNA primers with DNA,which really only needs to be done repetitively on one strand,while both strands are worked on by the DNA pol IIIs.

Question 15

Lagging stands are polymerized in the ______ direction,and the DNA fragments are about ______ nucleotides (nt)long in eukaryotic cells.

Accepted Answer

A) 5' to 3',100-200 
B) 5' to 3',1000-2000 
C) 3' to 5',100-400 
D) 3' to 5',1000-50000 
E) none of the above 
A) 5' to 3',100-200 
B) 5' to 3',1000-2000 
C) 3' to 5',100-400 
D) 3' to 5',1000-50000 
E) none of the above

Question 16

Free radical damage to DNA often results in
(I)pyrimidine dimers
(II)point mutations
(III)insertions
(IV)base excision

Accepted Answer

A) I only. 
B) II only. 
C) I,II. 
D) II,III. 
E) I,IV. 
A) I only. 
B) II only. 
C) I,II. 
D) II,III. 
E) I,IV.

Question 17

Matching
Choose the correct answer from the list.Not all the answers will be used.

-The process whereby nucleotides are removed from the 5' end of one DNA segment while nucleotides are added to the 3' end of the immediately preceding DNA segment is called ______.

Accepted Answer

A)  SSB 
B)  Tus 
C)  primosome 
D)  ARS 
E)  ATS
F) primer
G) transposons
H) nick translation
I) photolyase
J) processive
K) G-loops
L) G-quartets
M) accurate
N) lagging strand synthesis
O) MCM
P) abortive 
A)  SSB 
B)  Tus 
C)  primosome 
D)  ARS 
E)  ATS
F) primer
G) transposons
H) nick translation
I) photolyase
J) processive
K) G-loops
L) G-quartets
M) accurate
N) lagging strand synthesis
O) MCM
P) abortive

Question 18

Positive correlations between mutagenesis and carcinogenesis

Accepted Answer

A) are increased with teleomere capping. 
B) are reverted via nick translation. 
C) are examined using the Ames test. 
D) increase with photoreactivation. 
E) None of the above is correct . 
A) are increased with teleomere capping. 
B) are reverted via nick translation. 
C) are examined using the Ames test. 
D) increase with photoreactivation. 
E) None of the above is correct .

Question 19

Which of the following statements about the fidelity of replication is FALSE?

Accepted Answer

A) Cells maintaining an equal concentration of each dNTP helps maintain fidelity. 
B) DNA polymerase catalyzes synthesis in a two-stage reaction,ensuring the proper base is added. 
C) Cells viability is removed when DNA point mutations are incorporated. 
D) Pol I and Pol III are both involved in increasing fidelity. 
E) Specific repair systems repair and maintain DNA. 
A) Cells maintaining an equal concentration of each dNTP helps maintain fidelity. 
B) DNA polymerase catalyzes synthesis in a two-stage reaction,ensuring the proper base is added. 
C) Cells viability is removed when DNA point mutations are incorporated. 
D) Pol I and Pol III are both involved in increasing fidelity. 
E) Specific repair systems repair and maintain DNA.

Question 20

E.coli leading and lagging strand synthesis takes place at the

Accepted Answer

A) the Klenow fragment binding site. 
B) Pol III & Tus interface. 
C) multiprotein replisome. 
D) origin recognition complex. 
E) telomere. 
A) the Klenow fragment binding site. 
B) Pol III & Tus interface. 
C) multiprotein replisome. 
D) origin recognition complex. 
E) telomere.

Exam 25: DNA Replication, repair and Recombination

Pol I synthesizes new DNA with very high fidelity,due to its

The DNA sequence shown below is copied by the Klenow fragment.Which of the following would most likely result? 5' TGCGTGCACTCGA 3'

Capping is important because

Which of the following statements about Pol I is FALSE?

DNA ligase can be activated by which of the following? (I)The coupled hydrolysis of NAD+ to (NMN+)+ AMP. (II)The coupled hydrolysis of ATP to AMP + PPi. (III)The coupled hydrolysis of GTP to GMP + PPi.

Which of the following describes the Holliday junction?

Which of the following can be extended by DNA polymerase?

Matching Choose the correct answer from the list.Not all the answers will be used. -Enzymes that undergo many rounds of polymerization catalysis before dissociating from the substrate are described as highly ______.

Which of the following activities does E.coli DNA polymerase III contain? (I)5'→3' polymerase (II)5'→3' exonuclease (III)3'→5' exonuclease

Use the following diagram to complete the sentences below " ______ is the enzyme which catalyzes phosphodiester bond formation on both strands.Processivity of DNA pol is increased when associated with ____.DNA untwisting is accomplished by ______."

Which of the following enzymes catalyze the creation of AP sites for base excision repair?

Suppose Meselson & Stahl had observed the following data in their famous experiment involving a switch from medium containing 15N to 14N.What would they have concluded about the nature of DNA replication?

Which of the following describes the usefulness of primase?

A prokaryotic replisome typically contains two molecules of DNA pol III,but only one molecule of DNA pol I.Why?

Lagging stands are polymerized in the ______ direction,and the DNA fragments are about ______ nucleotides (nt)long in eukaryotic cells.

Free radical damage to DNA often results in (I)pyrimidine dimers (II)point mutations (III)insertions (IV)base excision

Matching Choose the correct answer from the list.Not all the answers will be used. -The process whereby nucleotides are removed from the 5' end of one DNA segment while nucleotides are added to the 3' end of the immediately preceding DNA segment is called ______.

Positive correlations between mutagenesis and carcinogenesis

Which of the following statements about the fidelity of replication is FALSE?

E.coli leading and lagging strand synthesis takes place at the

Introduction to the Chemistry of Life

Water

Nucleotides, nucleic Acids, and Genetic Information

Amino Acids

Proteins: Primary Structure

Proteins: Three-Dimensional Structure

Protein Function Part I: Myoglobin and Hemoglobin

Carbohydrates

Lipids and Biological Membranes

Membrane Transport

Enzyme Catalysis

Enzyme Kinetics, inhibition and Control

Biochemical Signaling

Introduction to Metabolism

Glucose Catabolism

Glycogen Metabolism and Gluconeogenesis

Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Photosynthesis

Lipid Metabolism

Amino Acid Metabolism

Mammalian Fuel Metabolism: Integration and Regulation

Nucleotide Metabolism

Nucleic Acid Structure

Transcription and Rna Processing

Protein Synthesis

Regulation of Gene Expression

Filters

DNA ligase can be activated by which of the following? (I)The coupled hydrolysis of NAD⁺ to (NMN⁺)+ AMP. (II)The coupled hydrolysis of ATP to AMP + PP_i. (III)The coupled hydrolysis of GTP to GMP + PP_i.

Use the following diagram to complete the sentences below " is the enzyme which catalyzes phosphodiester bond formation on both strands.Processivity of DNA pol is increased when associated with .DNA untwisting is accomplished by ."

Lagging stands are polymerized in the direction,and the DNA fragments are about nucleotides (nt)long in eukaryotic cells.