Question 1

Which type of replication results in 2 duplexes made of one parental strand and one newly synthesized strand?

Accepted Answer

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

Question 2

Replication moves outward from the origin in ________ direction(s)and is said to be ________.

Accepted Answer

A) both,unidirectional 
B) both,bidirectional 
C) one,bidirectional 
D) unique,unidirectional 
E) one,unidirectional

Question 3

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

Question 4

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) ARSs 
E) both autonomous replicating sequences and ARSs

Question 5

What technique was used in the discovery of the existence in eukaryotic cells of replicons,a discovery in which single DNA molecules were shown to be replicated simultaneously at several sites along their length?

Accepted Answer

A) scanning electron microscopy 
B) confocal laser scanning microscopy 
C) autoradiography 
D) polyacrylamide gel electrophoresis 
E) isoelectric focusing

Question 6

In bacteria,a _______ is formed when a ________ associates transiently with a _______.

Accepted Answer

A) primosome,helicase,DNA polymerase 
B) primosome,helicase,primase 
C) ribosome,helicase,primase 
D) helicosome,primosome,DNA polymerase 
E) primosome,helicase,DNA ligase

Question 7

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.

Question 8

Why is a single-stranded,circular DNA an ineffective template for DNA polymerase?

Accepted Answer

A) It has a 3'-hydroxyl group,but lacks a template. 
B) It lacks a 3'-hydroxyl group,but has a template. 
C) It lacks a 3'-hydroxyl group and a template. 
D) It has a 3'-hydroxyl group and has a template. 
E) It lacks a 5'-hydroxyl group and has a template.

Question 9

What is the most common mechanism for repairing damage to DNA?

Accepted Answer

A) direct repair of the damage 
B) selective excision of the damaged section and use of the complementary strand to replace the excised portion 
C) simple removal of damaged portion without replacement 
D) simplistic repair of the damage 
E) altruistic repair of the damage

Question 10

What discovery suggested the presence of other DNA polymerases in bacteria besides the Kornberg DNA polymerase enzyme?

Accepted Answer

A) Kornberg DNA polymerase mutants died. 
B) Kornberg DNA polymerase mutants grew much more slowly. 
C) Mutants with <1% of the normal Kornberg DNA polymerase enzyme activity multiplied at a normal rate. 
D) Mutants with <1% of the normal Kornberg DNA polymerase enzyme activity multiplied at a low rate. 
E) Kornberg DNA polymerase mutants reproduced much faster than normal bacteria.

Question 11

The DNA polymerase can incorporate the wrong nucleotide occasionally.What is the probability that the wrong nucleotide is incorporated into the growing polynucleotide chain during replication?

Accepted Answer

A) fewer than 1 in 1 billion nucleotides 
B) about 1 in 1000 nucleotides 
C) fewer than 1 in about 4 million nucleotides 
D) about 1 in 100,000 to 1,000,000 nucleotides 
E) about 1 in 10,000 nucleotides

Question 12

The DNA polymerases in a relatively large family of polymerases in which each member is specialized for incorporating nucleotides opposite particular types of DNA lesions in the template strand engage in a type of DNA synthesis called __________.They have an unusually spacious active site that ____________.

Accepted Answer

A) translesion synthesis,unwinds DNA double helices 
B) translesion synthesis; is able to physically accommodate altered nucleotides that would not fit in the active site of a replicative polymerase 
C) transdimensional synthesis; incorporates the nucleotide that would have paired with the undamaged version of the template base 
D) transdimensional synthesis; unwinds DNA synthesis 
E) transliteral synthesis; is able to physically accommodate altered nucleotides that would not fit in the active site of a replicative polymerase

Question 13

The enzyme that joins the small fragments of the lagging strand together into a continuous strand is called _______.

Accepted Answer

A) DNA gyrase 
B) DNA ligase 
C) DNA polymerase 
D) primase 
E) deoxyribonuclease

Question 14

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.

Question 15

Who was the first to purify an enzyme from bacterial extracts that could incorporate DNA precursors into a polymer?

Accepted Answer

A) Arthur Kornberg 
B) James Watson 
C) Francis Crick 
D) Jacques Monod 
E) Joel B.Piperberg (I wish!)

Question 16

Bacteria are grown in a medium containing 15NH4Cl for a number of generations so that all of the DNA is made of fully "heavy" DNA.The bacteria are moved to a new medium and grown in 15NH4Cl so that all new DNA will be light.After one generation time,what does the DNA look like?

Accepted Answer

A) All of the DNA is made of 2 "light" strands. 
B) All of the DNA is made of 2 "heavy" strands. 
C) All of the DNA is made of 1 "heavy" strand and 1 "light" strand. 
D) Each strand is made of a mixture of "heavy" and "light" DNA,with each strand being between 75% and 100% "light". 
E) Half of the DNA is made of 2 "light" strands and half of the DNA is made of 2 "heavy" strands.

Question 17

After exonucleases have excised the damaged portion of DNA,how can DNA polymerase fill in the gap? Is there a primer?

Accepted Answer

The answer of After exonucleases have excised the damaged portion...

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 $\alpha$

Question 19

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 $\delta$ continues replication. 
D) The normal replicative DNA polymerase continues replication. 
E) The bypass DNA polymerase $\varepsilon$ continues replication.

Question 20

Why is an intact,linear double helix an ineffective template for DNA polymerase?

Accepted Answer

A) It has a 3'-hydroxyl group,but lacks a template. 
B) It lacks a 3'-hydroxyl group,but has a template. 
C) It lacks a 3'-hydroxyl group and a template. 
D) It has a 3'-hydroxyl group and has a template. 
E) It lacks a 5'-hydroxyl group and has a template.

Exam 13: Dna Replication and Repair

Which type of replication results in 2 duplexes made of one parental strand and one newly synthesized strand?

Replication moves outward from the origin in direction(s) and is said to be .

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

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 __________.

What technique was used in the discovery of the existence in eukaryotic cells of replicons,a discovery in which single DNA molecules were shown to be replicated simultaneously at several sites along their length?

In bacteria,a _ is formed when a associates transiently with a _.

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

Why is a single-stranded,circular DNA an ineffective template for DNA polymerase?

What is the most common mechanism for repairing damage to DNA?

What discovery suggested the presence of other DNA polymerases in bacteria besides the Kornberg DNA polymerase enzyme?

The DNA polymerase can incorporate the wrong nucleotide occasionally.What is the probability that the wrong nucleotide is incorporated into the growing polynucleotide chain during replication?

The DNA polymerases in a relatively large family of polymerases in which each member is specialized for incorporating nucleotides opposite particular types of DNA lesions in the template strand engage in a type of DNA synthesis called .They have an unusually spacious active site that __.

The enzyme that joins the small fragments of the lagging strand together into a continuous strand is called _______.

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?

Who was the first to purify an enzyme from bacterial extracts that could incorporate DNA precursors into a polymer?

Bacteria are grown in a medium containing ¹⁵NH₄Cl for a number of generations so that all of the DNA is made of fully "heavy" DNA.The bacteria are moved to a new medium and grown in ¹⁵NH₄Cl so that all new DNA will be light.After one generation time,what does the DNA look like?

After exonucleases have excised the damaged portion of DNA,how can DNA polymerase fill in the gap? Is there a primer?

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

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

Why is an intact,linear double helix an ineffective template for DNA polymerase?

Exam 13: Dna Replication and Repair

Which type of replication results in 2 duplexes made of one parental strand and one newly synthesized strand?

Replication moves outward from the origin in ________ direction(s) and is said to be ________.

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

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 __________.

What technique was used in the discovery of the existence in eukaryotic cells of replicons,a discovery in which single DNA molecules were shown to be replicated simultaneously at several sites along their length?

In bacteria,a _______ is formed when a ________ associates transiently with a _______.

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

Why is a single-stranded,circular DNA an ineffective template for DNA polymerase?

What is the most common mechanism for repairing damage to DNA?

What discovery suggested the presence of other DNA polymerases in bacteria besides the Kornberg DNA polymerase enzyme?

The DNA polymerase can incorporate the wrong nucleotide occasionally.What is the probability that the wrong nucleotide is incorporated into the growing polynucleotide chain during replication?

The enzyme that joins the small fragments of the lagging strand together into a continuous strand is called _______.

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?

Who was the first to purify an enzyme from bacterial extracts that could incorporate DNA precursors into a polymer?

Bacteria are grown in a medium containing 15NH4Cl for a number of generations so that all of the DNA is made of fully "heavy" DNA.The bacteria are moved to a new medium and grown in 15NH4Cl so that all new DNA will be light.After one generation time,what does the DNA look like?

After exonucleases have excised the damaged portion of DNA,how can DNA polymerase fill in the gap? Is there a primer?

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

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

Why is an intact,linear double helix an ineffective template for DNA polymerase?

Replication moves outward from the origin in direction(s) and is said to be .

In bacteria,a _ is formed when a associates transiently with a _.

Bacteria are grown in a medium containing ¹⁵NH₄Cl for a number of generations so that all of the DNA is made of fully "heavy" DNA.The bacteria are moved to a new medium and grown in ¹⁵NH₄Cl so that all new DNA will be light.After one generation time,what does the DNA look like?