Question 1

A cross is made between yeast cells with different alleles for a set of linked genes: pr+q × p+rq+.The resulting tetrads show a 3:1 ratio for r+ to r instead of the expected 2:2 ratio.Can you explain how this could have occurred?

Accepted Answer

Gene conversion by a mismatch repair mec...

Question 2

In E.coli,replication begins at which chromosome site?

Accepted Answer

A)  The replication fork
B)  ter
C)  oriC
D)  TBP
E)  All of theseF) A) and D)
G) C) and D)

Question 3

As helicase unwinds the DNA molecule,what keeps the strands apart?

Accepted Answer

A)  DNA polymerase
B)  Reverse transcriptase
C)  Replication fork
D)  Single-strand binding proteins
E)  Okazaki fragmentsF) All of the above
G) A) and D)

Question 4

How many replication forks are produced when DNA denatures at an origin?

Accepted Answer

A)  0
B)  1
C)  2
D)  3
E)  The number variesF) C) and D)
G) B) and E)

Question 5

Only the leading strand of a DNA molecule serves as a template during replication.

Accepted Answer

A) True 
 B)False

Question 6

What are some key differences in replication between E.coli DNA and λ phage DNA?

Accepted Answer

Both start replication as a circular mol...

Question 7

How will DNA replication be affected if DNA polymerase I has a mutation that inactivates 5'-to-3' exonuclease activity?

Accepted Answer

The 5'-to-3' exonuclease activity of DNA...

Question 8

During replication,the direction of synthesis of new DNA from the leading and lagging strands is

Accepted Answer

A)  5' to 3' only.
B)  3' to 5' only.
C)  from left to right only.
D)  both 5' to 3' and 3' to 5'.
E)  different,depending on whether the cell is prokaryotic or eukaryotic.F) C) and D)
G) B) and D)

Question 9

Which enzyme elongates the new DNA strand starting at an RNA primer?

Accepted Answer

A)  DNA polymerase I
B)  DNA polymerase III
C)  RNA primase
D)  DNA ligase
E)  RNA polymeraseF) A) and B)
G) B) and C)

Question 10

In eukaryotic cells,histone proteins are actively synthesized during the S phase of the cell cycle.

Accepted Answer

A) True 
 B)False

Question 11

Match between columns
                        Premises: Replicon
Primosome
Telomerase
Replicator
Replisome

Accepted Answer

The Answer of A complex of helicase and primase on is...

Question 12

What are the key replication enzymes at the replisome,and how is DNA replication on both leading and lagging strands made efficient through the conformation of the DNA at the replisome in prokaryotes?

Accepted Answer

The key replication enzymes at the repli...

Question 13

Describe the method devised by Arthur Kornberg which first successfully achieved DNA synthesis in vitro,including its components and their uses.

Accepted Answer

Kornberg mixed together DNA fragments,al...

Question 14

Rolling circle replication of DNA is characterized by the absence of

Accepted Answer

A)  the DNA polymerase.
B)  a nick in the DNA template.
C)  the RNA primers.
D)  the replication bubble.
E)  the Okazaki fragments.F) A) and C)
G) C) and E)

Question 15

DNA polymerase III is very inaccurate at matching bases during replication,with errors in one out of every 100 base pairs.

Accepted Answer

A) True 
 B)False

Question 16

Which kind of enzyme prevents DNA from tangling up by introducing negative supercoils as the replication fork migrates during replication?

Accepted Answer

A)  Helicase
B)  Ligase
C)  DNA polymerase I
D)  DNA polymerase III
E)  TopoisomeraseF) B) and D)
G) A) and C)

Question 17

After a region of DNA has been replicated,________ removes the RNA primers.

Accepted Answer

A)  DNA polymerase I
B)  DNA polymerase III
C)  DNA helicase
D)  RNA primase
E)  DNA ligaseF) C) and D)
G) B) and C)

Question 18

Mg2+ ions are required for optimal DNA polymerase activity.

Accepted Answer

A) True 
 B)False

Question 19

DNA replication is always

Accepted Answer

A)  discontinuous.
B)  bidirectional.
C)  conservative.
D)  semiconservative.
E)  dispersive.F) B) and C)
G) C) and E)

Question 20

The diploid set of chromosomes in Drosophila embryos replicates six times faster than the single E.coli chromosome,even though there is about 100 times more DNA in Drosophila than in E.coli and the rate of movement of the replication fork in Drosophila is much slower.How is this so?

Accepted Answer

Eukaryotic chromosomes duplicate rapidly...

Exam 3: DNA Replication

A cross is made between yeast cells with different alleles for a set of linked genes: pr^+q × p^+rq+.The resulting tetrads show a 3:1 ratio for r⁺to r instead of the expected 2:2 ratio.Can you explain how this could have occurred?

Correct Answer
verified
Gene conversion by a mismatch repair mec...
View Answer

What are the key replication enzymes at the replisome,and how is DNA replication on both leading and lagging strands made efficient through the conformation of the DNA at the replisome in prokaryotes?

Correct Answer
verified
The key replication enzymes at the repli...
View Answer

Describe the method devised by Arthur Kornberg which first successfully achieved DNA synthesis in vitro,including its components and their uses.

Correct Answer
verified
Kornberg mixed together DNA fragments,al...
View Answer

As helicase unwinds the DNA molecule,what keeps the strands apart?

Correct Answer
verified

The diploid set of chromosomes in Drosophila embryos replicates six times faster than the single E.coli chromosome,even though there is about 100 times more DNA in Drosophila than in E.coli and the rate of movement of the replication fork in Drosophila is much slower.How is this so?

Correct Answer
verified
Eukaryotic chromosomes duplicate rapidly...
View Answer

During replication,the direction of synthesis of new DNA from the leading and lagging strands is

Correct Answer
verified

In eukaryotic cells,histone proteins are actively synthesized during the S phase of the cell cycle.

Correct Answer
verified

In E.coli,replication begins at which chromosome site?

Correct Answer
verified

How will DNA replication be affected if DNA polymerase I has a mutation that inactivates 5'-to-3' exonuclease activity?

Correct Answer
verified
The 5'-to-3' exonuclease activity of DNA...
View Answer

Which kind of enzyme prevents DNA from tangling up by introducing negative supercoils as the replication fork migrates during replication?

Correct Answer
verified

Only the leading strand of a DNA molecule serves as a template during replication.

Correct Answer
verified

Which enzyme elongates the new DNA strand starting at an RNA primer?

Correct Answer
verified

Rolling circle replication of DNA is characterized by the absence of

Correct Answer
verified

What are some key differences in replication between E.coli DNA and λ phage DNA?

Correct Answer
verified
Both start replication as a circular mol...
View Answer

Mg²⁺ ions are required for optimal DNA polymerase activity.

Correct Answer
verified

After a region of DNA has been replicated,________ removes the RNA primers.

Correct Answer
verified

DNA polymerase III is very inaccurate at matching bases during replication,with errors in one out of every 100 base pairs.

Correct Answer
verified

How many replication forks are produced when DNA denatures at an origin?

Correct Answer
verified

DNA replication is always

Correct Answer
verified

Please select the best match for each term.

Exam 3: DNA Replication

A cross is made between yeast cells with different alleles for a set of linked genes: pr+q × p+rq+.The resulting tetrads show a 3:1 ratio for r+ to r instead of the expected 2:2 ratio.Can you explain how this could have occurred?

Correct AnswerverifiedGene conversion by a mismatch repair mec...View AnswerShow Answer

What are the key replication enzymes at the replisome,and how is DNA replication on both leading and lagging strands made efficient through the conformation of the DNA at the replisome in prokaryotes?

Correct AnswerverifiedThe key replication enzymes at the repli...View AnswerShow Answer

Describe the method devised by Arthur Kornberg which first successfully achieved DNA synthesis in vitro,including its components and their uses.

Correct AnswerverifiedKornberg mixed together DNA fragments,al...View AnswerShow Answer

As helicase unwinds the DNA molecule,what keeps the strands apart?

Correct AnswerverifiedShow Answer

The diploid set of chromosomes in Drosophila embryos replicates six times faster than the single E.coli chromosome,even though there is about 100 times more DNA in Drosophila than in E.coli and the rate of movement of the replication fork in Drosophila is much slower.How is this so?

Correct AnswerverifiedEukaryotic chromosomes duplicate rapidly...View AnswerShow Answer

During replication,the direction of synthesis of new DNA from the leading and lagging strands is

Correct AnswerverifiedShow Answer

In eukaryotic cells,histone proteins are actively synthesized during the S phase of the cell cycle.

Correct AnswerverifiedShow Answer

In E.coli,replication begins at which chromosome site?

Correct AnswerverifiedShow Answer

How will DNA replication be affected if DNA polymerase I has a mutation that inactivates 5'-to-3' exonuclease activity?

Correct AnswerverifiedThe 5'-to-3' exonuclease activity of DNA...View AnswerShow Answer

Which kind of enzyme prevents DNA from tangling up by introducing negative supercoils as the replication fork migrates during replication?

Correct AnswerverifiedShow Answer

Only the leading strand of a DNA molecule serves as a template during replication.

Correct AnswerverifiedShow Answer

Which enzyme elongates the new DNA strand starting at an RNA primer?

Correct AnswerverifiedShow Answer

Rolling circle replication of DNA is characterized by the absence of

Correct AnswerverifiedShow Answer

What are some key differences in replication between E.coli DNA and λ phage DNA?

Correct AnswerverifiedBoth start replication as a circular mol...View AnswerShow Answer

Mg2+ ions are required for optimal DNA polymerase activity.

Correct AnswerverifiedShow Answer

After a region of DNA has been replicated,________ removes the RNA primers.

Correct AnswerverifiedShow Answer

DNA polymerase III is very inaccurate at matching bases during replication,with errors in one out of every 100 base pairs.

Correct AnswerverifiedShow Answer

How many replication forks are produced when DNA denatures at an origin?

Correct AnswerverifiedShow Answer

DNA replication is always

Correct AnswerverifiedShow Answer

Please select the best match for each term.

A cross is made between yeast cells with different alleles for a set of linked genes: pr^+q × p^+rq+.The resulting tetrads show a 3:1 ratio for r⁺to r instead of the expected 2:2 ratio.Can you explain how this could have occurred?

Correct Answer
verified
Gene conversion by a mismatch repair mec...
View Answer

Correct Answer
verified
The key replication enzymes at the repli...
View Answer

Correct Answer
verified
Kornberg mixed together DNA fragments,al...
View Answer

Correct Answer
verified

Correct Answer
verified
Eukaryotic chromosomes duplicate rapidly...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
The 5'-to-3' exonuclease activity of DNA...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Both start replication as a circular mol...
View Answer

Mg²⁺ ions are required for optimal DNA polymerase activity.

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified