Question 1

What is the advantage of transcription-coupled repair?

Accepted Answer

A) It allows the cell to do two things at once. 
B) It ensures that the genes of least importance to the cell receive the highest priority on the repair list. 
C) It ensures that the genes of greatest importance to the cell receive the highest priority on the repair list. 
D) It is repairs noncoding sequences preferentially. 
E) It is the most accurate method of repair. 
A) It allows the cell to do two things at once. 
B) It ensures that the genes of least importance to the cell receive the highest priority on the repair list. 
C) It ensures that the genes of greatest importance to the cell receive the highest priority on the repair list. 
D) It is repairs noncoding sequences preferentially. 
E) It is the most accurate method of repair.

Question 2

Where is DNA gyrase normally positioned as it changes positively supercoiled DNA into negatively supercoiled DNA in the replicating circular,bacterial chromosome?

Accepted Answer

A) It is permanently located at the origin. 
B) It travels along the DNA behind the replication fork. 
C) It travels along the DNA ahead of the replication fork. 
D) It travels along the DNA at the replication fork as part of the replisome. 
E) It is permanently located at the termination site of replication. 
A) It is permanently located at the origin. 
B) It travels along the DNA behind the replication fork. 
C) It travels along the DNA ahead of the replication fork. 
D) It travels along the DNA at the replication fork as part of the replisome. 
E) It is permanently located at the termination site of replication.

Question 3

Which DNA polymerase in bacteria is mostly involved in DNA repair to correct damaged DNA sections and removes RNA primers at the 5' ends of Okazaki fragments,replacing them with DNA?

Accepted Answer

A) DNA polymerase I 
B) DNA polymerase II 
C) DNA polymerase III 
D) DNA polymerase IV 
E) both DNA polymerase I and DNA polymerase III 
A) DNA polymerase I 
B) DNA polymerase II 
C) DNA polymerase III 
D) DNA polymerase IV 
E) both DNA polymerase I and DNA polymerase III

Question 4

The PCNA sliding clamp used in eukaryotic replication was first discovered as an antigen that reacted with the autoantibodies of patients suffering from what disease?

Accepted Answer

A) lupus erythematosus 
B) diabetes 
C) rheumatoid arthritis 
D) myasthenia gravis 
E) multiple sclerosis 
A) lupus erythematosus 
B) diabetes 
C) rheumatoid arthritis 
D) myasthenia gravis 
E) multiple sclerosis

Question 5

Which of the following may be a further advantage of using RNA primers during initiation of a strand in replication?

Accepted Answer

A) Using primers may decrease mistakes;such errors as mismatched bases are more likely during initiation than elongation,and the use of a short,removable RNA segment avoids inclusion of mismatched bases. 
B) Using primers is faster. 
C) The RNA of the primers is more stable. 
D) The RNA of the primers is more likely to lead to changes in base sequence,which enhances the rate of mutation and thus evolution. 
E) The RNA of the primers allows more efficient packing of the chromosomes after its removal. 
A) Using primers may decrease mistakes;such errors as mismatched bases are more likely during initiation than elongation,and the use of a short,removable RNA segment avoids inclusion of mismatched bases. 
B) Using primers is faster. 
C) The RNA of the primers is more stable. 
D) The RNA of the primers is more likely to lead to changes in base sequence,which enhances the rate of mutation and thus evolution. 
E) The RNA of the primers allows more efficient packing of the chromosomes after its removal.

Question 6

Who was the first to suggest semiconservative replication?

Accepted Answer

A) Meselson and Stahl 
B) Hershey and Chase 
C) Watson and Crick 
D) Avery,McCarty and MacLeod 
E) Darwin and Wallace 
A) Meselson and Stahl 
B) Hershey and Chase 
C) Watson and Crick 
D) Avery,McCarty and MacLeod 
E) Darwin and Wallace

Question 7

How can the replication of both DNA strands by two tethered polymerases be accomplished when the template strands run in opposite directions?

Accepted Answer

A) One of the enzymes polymerizes DNA in the 3'->5' direction. 
B) The DNA of the lagging strand loops back on itself so it has same orientation as the leading strand template. 
C) The DNA of the leading strand loops back on itself so it has same orientation as the lagging strand template. 
D) The lagging strand is broken and then rejoined regularly to allow simultaneous synthesis. 
E) It just is. 
A) One of the enzymes polymerizes DNA in the 3'->5' direction. 
B) The DNA of the lagging strand loops back on itself so it has same orientation as the leading strand template. 
C) The DNA of the leading strand loops back on itself so it has same orientation as the lagging strand template. 
D) The lagging strand is broken and then rejoined regularly to allow simultaneous synthesis. 
E) It just is.

Question 8

What happens once damage caused by lesions in the genome,like a thymidine dimer,is bypassed during replication and replication must continue?

Accepted Answer

A) The bypass DNA polymerase $\eta$ continues replication. 
B) The replicative DNA polymerase $\eta$continues replication. 
C) The bypass DNA polymerase $\eta$continues replication. 
D) The normal replicative DNA polymerase continues replication. 
E) The bypass DNA polymerase $\eta$ continues replication.. 
A) The bypass DNA polymerase $\eta$ continues replication. 
B) The replicative DNA polymerase $\eta$continues replication. 
C) The bypass DNA polymerase $\eta$continues replication. 
D) The normal replicative DNA polymerase continues replication. 
E) The bypass DNA polymerase $\eta$ continues replication..

Question 9

A double-stranded breakage repair pathway that requires the presence of a second chromosome carrying the same sequence of genes as the damaged chromosome is called _________.

Accepted Answer

A) nonhomologous end joining repair 
B) homologous recombination 
C) NHEJ 
D) DNA methylation repair 
E) nonhomologous recombination 
A) nonhomologous end joining repair 
B) homologous recombination 
C) NHEJ 
D) DNA methylation repair 
E) nonhomologous recombination

Question 10

The stepwise assembly of nucleosomes and their orderly spacing along the DNA is facilitated by what?

Accepted Answer

A) a network of accessory proteins 
B) a number of histone chaperones that are able to accept newly synthesized histones and transfer them to daughter strands 
C) a number of histone chaperones that are able to accept parental histones and transfer them to daughter strands 
D) CAF-1,which is able to accept either parental histones or newly synthesized histones and transfer them to daughter strands 
E) All of these are correct. 
A) a network of accessory proteins 
B) a number of histone chaperones that are able to accept newly synthesized histones and transfer them to daughter strands 
C) a number of histone chaperones that are able to accept parental histones and transfer them to daughter strands 
D) CAF-1,which is able to accept either parental histones or newly synthesized histones and transfer them to daughter strands 
E) All of these are correct.

Question 11

In early experiments with DNA polymerase I,what evidence convinced investigators that the original unlabeled DNA in the reaction mixture served as the template for the newly made DNA?

Accepted Answer

A) The new DNA had the same base composition as the original unlabeled DNA. 
B) The new DNA had a variable base composition. 
C) The new DNA had a triple helix. 
D) The new DNA and the old DNA were made of the same elements. 
E) The new DNA was equally stable. 
A) The new DNA had the same base composition as the original unlabeled DNA. 
B) The new DNA had a variable base composition. 
C) The new DNA had a triple helix. 
D) The new DNA and the old DNA were made of the same elements. 
E) The new DNA was equally stable.

Question 12

What is responsible for filling the gap left by the nucleases that digest the primer and the short DNA segment added to it by polymerase ?

Accepted Answer

A) DNA polymerase $\beta$ 
B) DNA polymerase $\delta$ 
C) DNA polymerase $\varepsilon$ 
D) both DNA polymerase $\beta$ and DNA polymerase $\delta$ 
E) RNase H1 
A) DNA polymerase $\beta$ 
B) DNA polymerase $\delta$ 
C) DNA polymerase $\varepsilon$ 
D) both DNA polymerase $\beta$ and DNA polymerase $\delta$ 
E) RNase H1

Question 13

Which eukaryotic DNA polymerase functions in DNA repair,but does not appear to be involved in nuclear DNA replication?

Accepted Answer

A) polymerase$\gamma$ 
B) polymerase  $\delta$ 
C) polymerase $\varepsilon$ 
D) polymerase $\beta$ 
E) polymerase $\alpha$ 
A) polymerase$\gamma$ 
B) polymerase  $\delta$ 
C) polymerase $\varepsilon$ 
D) polymerase $\beta$ 
E) polymerase $\alpha$

Question 14

In mammalian cells,a complex of proteins binds to the broken ends of the DNA duplex and catalyzes a series of reactions that rejoin the broken strands.This is an example of what kind of repair?

Accepted Answer

A) nucleotide excision repair 
B) base excision repair 
C) mismatch repair 
D) double-strand breakage repair 
E) nonhomologous end joining 
A) nucleotide excision repair 
B) base excision repair 
C) mismatch repair 
D) double-strand breakage repair 
E) nonhomologous end joining

Question 15

Cultured mammalian cells grown in thymidine for many generations were allowed to undergo replication in the presence of bromodeoxyuridine (BrdU),which replaces thymidine in DNA.After one round of replication,what does the DNA look like?

Accepted Answer

A) All chromatids have one strand that contains BrdU and one strand that contains thymidine. 
B) All chromatids have two strands that contain BrdU. 
C) Half of the chromatids have two strands that contain BrdU and half of the chromatids have 2 strands lacking BrdU. 
D) Both of the strands of each chromatid contain mixtures of BrdU and thymidine. 
E) All chromatids lack BrdU. 
A) All chromatids have one strand that contains BrdU and one strand that contains thymidine. 
B) All chromatids have two strands that contain BrdU. 
C) Half of the chromatids have two strands that contain BrdU and half of the chromatids have 2 strands lacking BrdU. 
D) Both of the strands of each chromatid contain mixtures of BrdU and thymidine. 
E) All chromatids lack BrdU.

Question 16

Cultured mammalian cells grown in thymidine for many generations were allowed to undergo replication in the presence of bromodeoxyuridine (BrdU),which replaces thymidine in DNA.After one round of replication,what would the DNA look like if replication were dispersive?

Accepted Answer

A) All chromatids have one strand that contains BrdU and one strand that does not. 
B) All chromatids have two strands that contain BrdU. 
C) Half of the chromatids have two strands that contain BrdU and half of the chromatids have 2 strands lacking BrdU. 
D) Both strands of each chromatid contain mixtures of BrdU and thymidine. 
E) All chromatids lack BrdU. 
A) All chromatids have one strand that contains BrdU and one strand that does not. 
B) All chromatids have two strands that contain BrdU. 
C) Half of the chromatids have two strands that contain BrdU and half of the chromatids have 2 strands lacking BrdU. 
D) Both strands of each chromatid contain mixtures of BrdU and thymidine. 
E) All chromatids lack BrdU.

Question 17

Which DNA repair mechanism recognizes a distortion in double helix geometry caused by DNA polymerase's insertion of an incorrect nucleotide during replication,one that escaped the enzyme's proofreading exonuclease?

Accepted Answer

A) nucleotide excision repair 
B) base excision repair 
C) mismatch repair 
D) double-strand breakage repair 
E) transcription-coupled pathway 
A) nucleotide excision repair 
B) base excision repair 
C) mismatch repair 
D) double-strand breakage repair 
E) transcription-coupled pathway

Question 18

The replication fork generates _______ supercoils in the _______ portion of the DNA molecule.

Accepted Answer

A) negative,replicated 
B) positive,replicated 
C) neutral,unreplicated 
D) positive,unreplicated 
E) negative,unreplicated 
A) negative,replicated 
B) positive,replicated 
C) neutral,unreplicated 
D) positive,unreplicated 
E) negative,unreplicated

Question 19

If cells are given a very short exposure to radioactive DNA nucleotide precursors followed by unlabeled DNA precursors for an hour or so before fixation,where is most of the radiolabel located?

Accepted Answer

A) in the cytoplasm 
B) associated with the nuclear matrix 
C) in the mitochondria 
D) in the DNA loops surrounding the nuclear matrix 
E) in the mesosome 
A) in the cytoplasm 
B) associated with the nuclear matrix 
C) in the mitochondria 
D) in the DNA loops surrounding the nuclear matrix 
E) in the mesosome

Question 20

What is responsible for removing the RNA primer and short DNA segment added by eukaryotic DNA polymerase $\alpha$?

Accepted Answer

A) FEN-1 
B) DNA polymerase  $\delta$ 
C) DNase H 
D) both FEN-1 and DNase H 
E) DNA ligase 
A) FEN-1 
B) DNA polymerase  $\delta$ 
C) DNase H 
D) both FEN-1 and DNase H 
E) DNA ligase

What is the advantage of transcription-coupled repair?

Where is DNA gyrase normally positioned as it changes positively supercoiled DNA into negatively supercoiled DNA in the replicating circular,bacterial chromosome?

Which DNA polymerase in bacteria is mostly involved in DNA repair to correct damaged DNA sections and removes RNA primers at the 5' ends of Okazaki fragments,replacing them with DNA?

The PCNA sliding clamp used in eukaryotic replication was first discovered as an antigen that reacted with the autoantibodies of patients suffering from what disease?

Which of the following may be a further advantage of using RNA primers during initiation of a strand in replication?

Who was the first to suggest semiconservative replication?

How can the replication of both DNA strands by two tethered polymerases be accomplished when the template strands run in opposite directions?

What happens once damage caused by lesions in the genome,like a thymidine dimer,is bypassed during replication and replication must continue?

A double-stranded breakage repair pathway that requires the presence of a second chromosome carrying the same sequence of genes as the damaged chromosome is called _________.

The stepwise assembly of nucleosomes and their orderly spacing along the DNA is facilitated by what?

In early experiments with DNA polymerase I,what evidence convinced investigators that the original unlabeled DNA in the reaction mixture served as the template for the newly made DNA?

What is responsible for filling the gap left by the nucleases that digest the primer and the short DNA segment added to it by polymerase ?

Which eukaryotic DNA polymerase functions in DNA repair,but does not appear to be involved in nuclear DNA replication?

In mammalian cells,a complex of proteins binds to the broken ends of the DNA duplex and catalyzes a series of reactions that rejoin the broken strands.This is an example of what kind of repair?

Cultured mammalian cells grown in thymidine for many generations were allowed to undergo replication in the presence of bromodeoxyuridine (BrdU),which replaces thymidine in DNA.After one round of replication,what does the DNA look like?

Cultured mammalian cells grown in thymidine for many generations were allowed to undergo replication in the presence of bromodeoxyuridine (BrdU),which replaces thymidine in DNA.After one round of replication,what would the DNA look like if replication were dispersive?

Which DNA repair mechanism recognizes a distortion in double helix geometry caused by DNA polymerase's insertion of an incorrect nucleotide during replication,one that escaped the enzyme's proofreading exonuclease?

The replication fork generates _ supercoils in the _ portion of the DNA molecule.

If cells are given a very short exposure to radioactive DNA nucleotide precursors followed by unlabeled DNA precursors for an hour or so before fixation,where is most of the radiolabel located?

What is responsible for removing the RNA primer and short DNA segment added by eukaryotic DNA polymerase $\alpha$ ?

Introduction to the Study of Cell and Molecular Biology

The Chemical Basis of Life

Bioenergetics, Enzymes, and Metabolism

The Structure and Function of the Plasma Membrane

Aerobic Respiration and the Mitochondrion

Photosynthesis and the Chloroplast

Interactions Between Cells and Their Environment

Cytoplasmic Membrane Systems: Structure, Function, and Membrane Trafficking

The Cytoskeleton and Cell Motility

The Nature of the Gene and the Genome

Gene Expression: From Transcription to Translation

Control of Gene Expression

Cellular Reproduction

Cell Signaling and Signal Transduction: Communication Between Cells

Cancer

The Immune Response

Techniques in Cell and Molecular Biology

Filters

Exam 13: Dna Replication and Repair

What is the advantage of transcription-coupled repair?

Where is DNA gyrase normally positioned as it changes positively supercoiled DNA into negatively supercoiled DNA in the replicating circular,bacterial chromosome?

Which DNA polymerase in bacteria is mostly involved in DNA repair to correct damaged DNA sections and removes RNA primers at the 5' ends of Okazaki fragments,replacing them with DNA?

The PCNA sliding clamp used in eukaryotic replication was first discovered as an antigen that reacted with the autoantibodies of patients suffering from what disease?

Which of the following may be a further advantage of using RNA primers during initiation of a strand in replication?

Who was the first to suggest semiconservative replication?

How can the replication of both DNA strands by two tethered polymerases be accomplished when the template strands run in opposite directions?

What happens once damage caused by lesions in the genome,like a thymidine dimer,is bypassed during replication and replication must continue?

A double-stranded breakage repair pathway that requires the presence of a second chromosome carrying the same sequence of genes as the damaged chromosome is called _________.

The stepwise assembly of nucleosomes and their orderly spacing along the DNA is facilitated by what?

In early experiments with DNA polymerase I,what evidence convinced investigators that the original unlabeled DNA in the reaction mixture served as the template for the newly made DNA?

What is responsible for filling the gap left by the nucleases that digest the primer and the short DNA segment added to it by polymerase ?

Which eukaryotic DNA polymerase functions in DNA repair,but does not appear to be involved in nuclear DNA replication?

In mammalian cells,a complex of proteins binds to the broken ends of the DNA duplex and catalyzes a series of reactions that rejoin the broken strands.This is an example of what kind of repair?

Cultured mammalian cells grown in thymidine for many generations were allowed to undergo replication in the presence of bromodeoxyuridine (BrdU),which replaces thymidine in DNA.After one round of replication,what does the DNA look like?

Cultured mammalian cells grown in thymidine for many generations were allowed to undergo replication in the presence of bromodeoxyuridine (BrdU),which replaces thymidine in DNA.After one round of replication,what would the DNA look like if replication were dispersive?

Which DNA repair mechanism recognizes a distortion in double helix geometry caused by DNA polymerase's insertion of an incorrect nucleotide during replication,one that escaped the enzyme's proofreading exonuclease?

The replication fork generates _______ supercoils in the _______ portion of the DNA molecule.

If cells are given a very short exposure to radioactive DNA nucleotide precursors followed by unlabeled DNA precursors for an hour or so before fixation,where is most of the radiolabel located?

What is responsible for removing the RNA primer and short DNA segment added by eukaryotic DNA polymerase α\alphaα ?

Introduction to the Study of Cell and Molecular Biology

The Chemical Basis of Life

Bioenergetics, Enzymes, and Metabolism

The Structure and Function of the Plasma Membrane

Aerobic Respiration and the Mitochondrion

Photosynthesis and the Chloroplast

Interactions Between Cells and Their Environment

Cytoplasmic Membrane Systems: Structure, Function, and Membrane Trafficking

The Cytoskeleton and Cell Motility

The Nature of the Gene and the Genome

Gene Expression: From Transcription to Translation

Control of Gene Expression

Cellular Reproduction

Cell Signaling and Signal Transduction: Communication Between Cells

Cancer

The Immune Response

Techniques in Cell and Molecular Biology

Filters

The replication fork generates _ supercoils in the _ portion of the DNA molecule.

What is responsible for removing the RNA primer and short DNA segment added by eukaryotic DNA polymerase $\alpha$ ?