Question 1

What happens to the RNA primers that initiate replication?

Accepted Answer

A) They are chemically altered to DNA. 
B) They are sealed into the DNA molecule with ligase. 
C) They are excised along with the complementary DNA. 
D) They are removed and replaced with DNA.

Question 2

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.

Question 3

All DNA polymerases lay down nucleotides in a ______ direction and move along the template in a _______ direction.

Accepted Answer

A) 3'->5', 5'->3' 
B) N->C. C->N 
C) 5'->3', 3'->5' 
D) C->N, N->C 
E) N->C, 5'->3'

Question 4

During replication of the lagging strand, DNA is constructed in small segments called ________ that are rapidly linked to longer pieces of DNA synthesized earlier.

Accepted Answer

A) Watson fragments 
B) Tokyo fragments 
C) Osaka fragments 
D) Okazaki fragments 
E) Ouabain fragments

Question 5

Which eukaryotic DNA polymerases require a sliding clamp to tether the DNA to the polymerase? (Select all correct choices)

Accepted Answer

A) polymerase α 
B) polymerase β 
C) polymerase ɤ 
D) polymerase δ 
E) polymerase ε

Question 6

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.

Question 7

The clamp loader that loads PCNA onto DNA is called _______ and is analogous to the E. coli DNA polymerase III clamp loader complex.

Accepted Answer

A) RFC 
B) KFC 
C) NBC 
D) TLC 
E) SEC

Question 8

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

Accepted Answer

A) polymerase α 
B) polymerase β 
C) polymerase ɤ 
D) polymerase δ 
E) polymerase ε

Question 9

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

Accepted Answer

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

Question 10

Which of the following DNA molecules could serve as an effective template for DNA synthesis in the early studies of DNA polymerase activity?

Accepted Answer

A) linear single-stranded DNA 
B) circular single-stranded DNA 
C) partially double-stranded DNA 
D) linear single-stranded RNA

Question 11

Which are advantages of using recombinant DNA technology when compared with the gamma garden method of detecting favorably mutated crop varieties? (Select all correct choices)

Accepted Answer

A) Recombinant DNA technology does not produce radioactive plants while gamma gardens did. 
B) Recombinant DNA technology is not accompanied by the risk of plant or animal exposure to radioactive isotopes while gamma gardens presented that potential danger. 
C) Recombinant DNA technology can produce targeted gene alterations which gamma garden mutations were randomly accumulated by plants. 
D) Recombinant DNA technology is slower to produce mutant plants, allowing for more deliberate study of their characteristics.

Question 12

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

Accepted Answer

A) polymerase α 
B) polymerase β 
C) polymerase ɤ 
D) polymerase δ 
E) polymerase ε

Question 13

What theory of replication results in the integrity of both parental strands being disrupted, the new duplex strands made of both old and new DNA and neither the parental strands nor the parental duplex preserved?.

Accepted Answer

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

Question 14

What proteins bind selectively to single-stranded DNA and are responsible for keeping it extended and preventing it from being rewound?

Accepted Answer

A) DNA helicase 
B) DNA gyrase 
C) single-stranded DNA binding (SS
B) proteins 
D) ATPase 
E) DNA unwindase

Question 15

Which method of repair can be slower, less efficient, and responsible for correcting DNA strands in the parts of the genome that are not being currently transcribed?

Accepted Answer

A) transcription-coupled pathway of NER 
B) global genomic pathway of NER 
C) base excision repair 
D) replicative repair

Question 16

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

Accepted Answer

A) Arthur Kornberg 
B) James Watson 
C) Francis Crick 
D) Jacques Monod

Question 17

What is the most common method 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) excision of both strands and annealing of the two ends of DNA back together

Question 18

Bacteria are grown in a medium containing [15N]H4Cl 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 [14N]H4Cl so that all subsequent new DNA will be "light". If replication were conservative, what would the DNA look like after two generation times have passed?

Accepted Answer

A) All of the DNA is made of two 'light' strands. 
B) Half of the DNA is made of two 'light' strands and half is made of one 'light' strand and one 'heavy' strand. 
C) All of the DNA is made of one 'heavy' strand and one '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) Three quarters of the DNA is made of two 'light' strands and one quarter is made of 2 'heavy' strands.

Question 19

In the transcription-coupled repair pathway of nucleotide excision repair, 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 20

Bacteria are grown in a medium containing [15N]H4Cl 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 [14N]H4Cl so that all subsequent 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 two 'light' strands. 
B) All of the DNA is made of two 'heavy' strands. 
C) All of the DNA is made of one 'heavy' strand and one '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 two 'light' strands and half is made of two 'heavy' strands.

Exam 13: Dna Replication and Repair

What happens to the RNA primers that initiate replication?

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

All DNA polymerases lay down nucleotides in a direction and move along the template in a _ direction.

During replication of the lagging strand, DNA is constructed in small segments called ________ that are rapidly linked to longer pieces of DNA synthesized earlier.

Which eukaryotic DNA polymerases require a sliding clamp to tether the DNA to the polymerase? (Select all correct choices)

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

The clamp loader that loads PCNA onto DNA is called _______ and is analogous to the E. coli DNA polymerase III clamp loader complex.

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

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

Which of the following DNA molecules could serve as an effective template for DNA synthesis in the early studies of DNA polymerase activity?

Which are advantages of using recombinant DNA technology when compared with the gamma garden method of detecting favorably mutated crop varieties? (Select all correct choices)

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

What theory of replication results in the integrity of both parental strands being disrupted, the new duplex strands made of both old and new DNA and neither the parental strands nor the parental duplex preserved?.

What proteins bind selectively to single-stranded DNA and are responsible for keeping it extended and preventing it from being rewound?

Which method of repair can be slower, less efficient, and responsible for correcting DNA strands in the parts of the genome that are not being currently transcribed?

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

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

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