Question 1

Which eukaryotic DNA polymerase is thought to be the primary DNA-synthesizing enzyme during replication of the lagging strand?

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 2

Why did Kornberg initially think that the exonuclease activity he found in his DNA polymerase preparations was a contaminating enzyme?

Accepted Answer

A) The action of exonucleases is a lot like endonuclease. 
B) The action of exonucleases is so dramatically opposed to the activity of DNA polymerases,the synthesis of DNA. 
C) The action of exonucleases is exactly like the action of DNA polymerase. 
D) Purification was so difficult. 
E) Enzymes can often run the reverse reactions. 
A) The action of exonucleases is a lot like endonuclease. 
B) The action of exonucleases is so dramatically opposed to the activity of DNA polymerases,the synthesis of DNA. 
C) The action of exonucleases is exactly like the action of DNA polymerase. 
D) Purification was so difficult. 
E) Enzymes can often run the reverse reactions.

Question 3

As replication proceeds,the lagging strand template of the DNA is looped back on itself so that it has the same orientation as the leading strand template;the looping DNA repeatedly grows and shortens during lagging strand replication.This model is often referred to as the _________.

Accepted Answer

A) telescope model 
B) extension model 
C) trombone model 
D) French horn model 
E) piccolo model 
A) telescope model 
B) extension model 
C) trombone model 
D) French horn model 
E) piccolo model

Question 4

Why did natural selection favor the use of thymine as a base in DNA instead of uracil even though uracil was presumably present in RNA,when it served as the genetic material during the early evolution of life?

Accepted Answer

A) Thymine was more stable. 
B) Thymine paired better with adenine than did uracil. 
C) Retention of uracil as a DNA base would make it hard to tell whether a uracil was supposed to be at a particular site or whether it resulted from damage to cytosine. 
D) Thymine is resistant to all chemical treatments. 
E) Retention of uracil as a DNA base would make it hard to tell whether a uracil was supposed to be at a particular site or whether it resulted from damage to guanine. 
A) Thymine was more stable. 
B) Thymine paired better with adenine than did uracil. 
C) Retention of uracil as a DNA base would make it hard to tell whether a uracil was supposed to be at a particular site or whether it resulted from damage to cytosine. 
D) Thymine is resistant to all chemical treatments. 
E) Retention of uracil as a DNA base would make it hard to tell whether a uracil was supposed to be at a particular site or whether it resulted from damage to guanine.

Question 5

At what stage of the cell cycle do the key protein kinases,like cyclin-dependent kinase become activated?

Accepted Answer

A) right after mitosis 
B) right before mitosis 
C) just before the start of S phase 
D) in the middle of the G2 phase 
E) in the G0 phase 
A) right after mitosis 
B) right before mitosis 
C) just before the start of S phase 
D) in the middle of the G2 phase 
E) in the G0 phase

Question 6

What binds to the ORC to assemble the prereplication complex (pre-RC)that is competent to initiate replication?

Accepted Answer

A) the ORC factors 
B) licensing factors 
C) competence factors 
D) initiation factors 
E) enlisting factors 
A) the ORC factors 
B) licensing factors 
C) competence factors 
D) initiation factors 
E) enlisting factors

Question 7

What evidence suggests that the assembly of DNA into nucleosomes is a very rapid event?

Accepted Answer

A) Radiolabel is incorporated in a very short time. 
B) Nucleosomes have a very unusual shape. 
C) Electron micrographs of replicating DNA show nucleosomes forming on both daughter duplexes very near the replication fork. 
D) Electron micrographs of replicating DNA show nucleosomes forming on both daughter duplexes at a large distance from the replication fork. 
E) Nucleosomes are twice as big near the replication fork. 
A) Radiolabel is incorporated in a very short time. 
B) Nucleosomes have a very unusual shape. 
C) Electron micrographs of replicating DNA show nucleosomes forming on both daughter duplexes very near the replication fork. 
D) Electron micrographs of replicating DNA show nucleosomes forming on both daughter duplexes at a large distance from the replication fork. 
E) Nucleosomes are twice as big near the replication fork.

Question 8

In replicating bacterial chromosomes,where does replication terminate?

Accepted Answer

A) at the origin 
B) across the circular chromosome from the origin 
C) at random locations around the circle 
D) one quarter of the way around the DNA circle from the origin 
E) near Arnold 
A) at the origin 
B) across the circular chromosome from the origin 
C) at random locations around the circle 
D) one quarter of the way around the DNA circle from the origin 
E) near Arnold

Question 9

What is the function of the 5'->3' exonuclease activity of DNA polymerase I?

Accepted Answer

A) It removes mismatched nucleotides that have been incorporated by mistake. 
B) It replaces mismatched nucleotides with the correctly matched nucleotides. 
C) It removes the DNA primer laid down by the primase at the 5' end of the Okazaki fragment. 
D) It removes the RNA primer laid down by the primase at the 5' end of the Okazaki fragment. 
E) It nicks DNA to create a primer in the middle of a DNA chain. 
A) It removes mismatched nucleotides that have been incorporated by mistake. 
B) It replaces mismatched nucleotides with the correctly matched nucleotides. 
C) It removes the DNA primer laid down by the primase at the 5' end of the Okazaki fragment. 
D) It removes the RNA primer laid down by the primase at the 5' end of the Okazaki fragment. 
E) It nicks DNA to create a primer in the middle of a DNA chain.

Question 10

Why does it appear that each origin can only be activated once per cell cycle?

Accepted Answer

A) Mcm proteins are displaced from the DNA after replication and cannot reassociate with a replication origin that has already fired. 
B) The ORC is denatured after replication and cannot return to the DNA. 
C) The DNA becomes naked until the next round of cell division. 
D) Mcm proteins reassociate with DNA immediately and prevent further replication from that DNA. 
E) Mcm proteins bind to other proteins in the cytoplasm;together they actively inhibit further replication. 
A) Mcm proteins are displaced from the DNA after replication and cannot reassociate with a replication origin that has already fired. 
B) The ORC is denatured after replication and cannot return to the DNA. 
C) The DNA becomes naked until the next round of cell division. 
D) Mcm proteins reassociate with DNA immediately and prevent further replication from that DNA. 
E) Mcm proteins bind to other proteins in the cytoplasm;together they actively inhibit further replication.

Question 11

What happens to DNA (circular DNA or linear DNA that is not free to rotate)when it becomes overwound?

Accepted Answer

A) It becomes negatively supercoiled. 
B) It breaks into a number of fragments. 
C) It becomes positively supercoiled. 
D) It stretches. 
E) Its mass decreases. 
A) It becomes negatively supercoiled. 
B) It breaks into a number of fragments. 
C) It becomes positively supercoiled. 
D) It stretches. 
E) Its mass decreases.

Question 12

In the transcription-coupled repair pathway,how is the presence of a lesion thought to be detected?

Accepted Answer

A) There are special enzymes that scan the DNA for such lesions. 
B) The lesion may be signaled by a stalled RNA polymerase. 
C) The lesion may be signaled by a stalled DNA polymerase. 
D) The lesion may be signaled by a stalled peptidyl transferase. 
E) The lesion may be detected single-stranded binding proteins. 
A) There are special enzymes that scan the DNA for such lesions. 
B) The lesion may be signaled by a stalled RNA polymerase. 
C) The lesion may be signaled by a stalled DNA polymerase. 
D) The lesion may be signaled by a stalled peptidyl transferase. 
E) The lesion may be detected single-stranded binding proteins.

Question 13

What type of replication results in the integrity of both parental strands being disrupted? The new duplex strands are made of both old and new DNA.Neither the parental strands nor the parental duplex is preserved.

Accepted Answer

A) semiconservative replication 
B) conservative replication 
C) dispersive replication 
D) incisive replication 
E) reservative replication 
A) semiconservative replication 
B) conservative replication 
C) dispersive replication 
D) incisive replication 
E) reservative replication

Question 14

What enzyme cleaves the DNA backbone to remove the beheaded deoxyribose phosphate during base excision repair?

Accepted Answer

A) an AP endonuclease 
B) phosphodiesterase activity of polymerase  
C) 5'->3' exonuclease 
D) 3'->5' exonuclease 
E) DNA glycosylase 
A) an AP endonuclease 
B) phosphodiesterase activity of polymerase  
C) 5'->3' exonuclease 
D) 3'->5' exonuclease 
E) DNA glycosylase

Question 15

The RNA primers that initiate replication are subsequently _____ and the resulting gap in the strand is _______ DNA and then sealed by _______.

Accepted Answer

A) filled in,removed by,DNA ligase 
B) removed,filled in with,DNA ligase 
C) removed,filled in with,RNA ligase 
D) chemically altered to DNA,excised,DNA ligase 
E) chemically altered to DNA,filled in with,DNA ligase 
A) filled in,removed by,DNA ligase 
B) removed,filled in with,DNA ligase 
C) removed,filled in with,RNA ligase 
D) chemically altered to DNA,excised,DNA ligase 
E) chemically altered to DNA,filled in with,DNA ligase

Question 16

The collection of proteins in eukaryotes that forms the replicative complex is known as the __________.

Accepted Answer

A) replicand 
B) replicon 
C) replisome 
D) replimere 
E) polymerizer 
A) replicand 
B) replicon 
C) replisome 
D) replimere 
E) polymerizer

Question 17

Which eukaryotic DNA polymerase replicates mitochondrial DNA and 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 18

Which eukaryotic DNA polymerase appears to be the primary DNA-synthesizing enzyme during replication of the lagging strand?

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 19

DNA sequences comprising the yeast origin of replication can be removed from yeast cells and inserted into bacterial DNA molecules.Because these sequences promote replication of the DNA in which they are contained,they are referred to as __________.

Accepted Answer

A) polygamous replicating sequences 
B) autonomous replicating sequences 
C) analogous replicating sequences 
D) both autonomous replicating sequences and ARSs 
E) ARSs 
A) polygamous replicating sequences 
B) autonomous replicating sequences 
C) analogous replicating sequences 
D) both autonomous replicating sequences and ARSs 
E) ARSs

Question 20

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 two rounds of replication,what would the DNA look like if replication were conservative?

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) 75% of the chromatids have two strands that contain BrdU and 25% of the chromatids have 1 strand lacking BrdU and 1 strand containing 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) 75% of the chromatids have two strands that contain BrdU and 25% of the chromatids have 1 strand lacking BrdU and 1 strand containing BrdU.

Which eukaryotic DNA polymerase is thought to be the primary DNA-synthesizing enzyme during replication of the lagging strand?

Why did Kornberg initially think that the exonuclease activity he found in his DNA polymerase preparations was a contaminating enzyme?

As replication proceeds,the lagging strand template of the DNA is looped back on itself so that it has the same orientation as the leading strand template;the looping DNA repeatedly grows and shortens during lagging strand replication.This model is often referred to as the _________.

Why did natural selection favor the use of thymine as a base in DNA instead of uracil even though uracil was presumably present in RNA,when it served as the genetic material during the early evolution of life?

At what stage of the cell cycle do the key protein kinases,like cyclin-dependent kinase become activated?

What binds to the ORC to assemble the prereplication complex (pre-RC)that is competent to initiate replication?

What evidence suggests that the assembly of DNA into nucleosomes is a very rapid event?

In replicating bacterial chromosomes,where does replication terminate?

What is the function of the 5'->3' exonuclease activity of DNA polymerase I?

Why does it appear that each origin can only be activated once per cell cycle?

What happens to DNA (circular DNA or linear DNA that is not free to rotate)when it becomes overwound?

In the transcription-coupled repair pathway,how is the presence of a lesion thought to be detected?

What type of replication results in the integrity of both parental strands being disrupted? The new duplex strands are made of both old and new DNA.Neither the parental strands nor the parental duplex is preserved.

What enzyme cleaves the DNA backbone to remove the beheaded deoxyribose phosphate during base excision repair?

The RNA primers that initiate replication are subsequently _ and the resulting gap in the strand is _ DNA and then sealed by _____.

The collection of proteins in eukaryotes that forms the replicative complex is known as the __________.

Which eukaryotic DNA polymerase replicates mitochondrial DNA and does not appear to be involved in nuclear DNA replication?

Which eukaryotic DNA polymerase appears to be the primary DNA-synthesizing enzyme during replication of the lagging strand?

DNA sequences comprising the yeast origin of replication can be removed from yeast cells and inserted into bacterial DNA molecules.Because these sequences promote replication of the DNA in which they are contained,they are referred to as __________.

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 two rounds of replication,what would the DNA look like if replication were conservative?

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

Which eukaryotic DNA polymerase is thought to be the primary DNA-synthesizing enzyme during replication of the lagging strand?

Why did Kornberg initially think that the exonuclease activity he found in his DNA polymerase preparations was a contaminating enzyme?

As replication proceeds,the lagging strand template of the DNA is looped back on itself so that it has the same orientation as the leading strand template;the looping DNA repeatedly grows and shortens during lagging strand replication.This model is often referred to as the _________.

Why did natural selection favor the use of thymine as a base in DNA instead of uracil even though uracil was presumably present in RNA,when it served as the genetic material during the early evolution of life?

At what stage of the cell cycle do the key protein kinases,like cyclin-dependent kinase become activated?

What binds to the ORC to assemble the prereplication complex (pre-RC)that is competent to initiate replication?

What evidence suggests that the assembly of DNA into nucleosomes is a very rapid event?

In replicating bacterial chromosomes,where does replication terminate?

What is the function of the 5'->3' exonuclease activity of DNA polymerase I?

Why does it appear that each origin can only be activated once per cell cycle?

What happens to DNA (circular DNA or linear DNA that is not free to rotate)when it becomes overwound?

In the transcription-coupled repair pathway,how is the presence of a lesion thought to be detected?

What type of replication results in the integrity of both parental strands being disrupted? The new duplex strands are made of both old and new DNA.Neither the parental strands nor the parental duplex is preserved.

What enzyme cleaves the DNA backbone to remove the beheaded deoxyribose phosphate during base excision repair?

The RNA primers that initiate replication are subsequently _____ and the resulting gap in the strand is _______ DNA and then sealed by _______.

The collection of proteins in eukaryotes that forms the replicative complex is known as the __________.

Which eukaryotic DNA polymerase replicates mitochondrial DNA and does not appear to be involved in nuclear DNA replication?

Which eukaryotic DNA polymerase appears to be the primary DNA-synthesizing enzyme during replication of the lagging strand?

DNA sequences comprising the yeast origin of replication can be removed from yeast cells and inserted into bacterial DNA molecules.Because these sequences promote replication of the DNA in which they are contained,they are referred to as __________.

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 two rounds of replication,what would the DNA look like if replication were conservative?

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 RNA primers that initiate replication are subsequently _ and the resulting gap in the strand is _ DNA and then sealed by _____.