Deck 13: Dna Replication and Repair

Question 1

The specific site on the bacterial chromosome at which replication begins is called the ________ of replication.

A)beginning
B)origin
C)initiation site
D)initiator
E)replicon

Answer 1

B

Question 2

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 does the DNA look like?

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 have two strands lacking BrdU.
D)Both strands of each chromatid contain mixtures of BrdU and thymidine.
E)Half of the chromatids have two strands that contain BrdU and half have one strand lacking BrdU and one strand containing BrdU.

Answer 2

E

Question 3

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?.

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

Answer 3

C

Question 4

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

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

Question 5

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

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

Question 6

In replicating bacterial chromosomes, where does replication terminate?

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

Question 7

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

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 8

Who was the first to suggest semiconservative replication?

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

Question 9

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?

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.

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?

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

Question 11

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?

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 have two strands lacking BrdU.
D)Both strands of each chromatid contain mixtures of BrdU and thymidine.
E)All chromatids lack BrdU.

Question 12

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?

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 13

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?

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 have two strands lacking BrdU.
D)Both strands of each chromatid contain mixtures of BrdU and thymidine.
E)Three quarters of the chromatids have two strands that contain BrdU and one quarter have two strands lacking BrdU.

Question 14

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 dispersive, what would the DNA look like after two generation times?

A)All of the DNA is made of two 'light' strands.
B)Half of the DNA is made of two 'light' strands and half of the DNA 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 two 'heavy' strands.

Question 15

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

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

Question 16

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

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

Question 17

What supplies the energy that drives the relief of mechanical strain by DNA gyrase?

A)condensation of ATP
B)condensation of GTP
C)hydrolysis of ATP
D)hydrolysis of GTP
E)a proton gradient

Question 18

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?

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 have two strands lacking BrdU.
D)Both of the strands of each chromatid contain mixtures of BrdU and thymidine.
E)All chromatids lack BrdU.

Question 19

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

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 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". If replication were conservative, what would the DNA look like after two generation times have passed?

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 21

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

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

Question 22

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?

A)DNA polymerase I
B)DNA polymerase II
C)DNA polymerase III
D)DNA polymerase IV

Question 23

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

A)It has a 3'-hydroxyl terminus, but lacks a template.
B)It lacks a 3'-hydroxyl primer, 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 24

Strand initiation during replication is carried out by an enzyme that makes a short RNA molecule that is used as a primer; the enzyme is a distinct type of RNA polymerase, called _______.

A)RNA gyrase
B)RNA ligase
C)ribonuclease
D)primase
E)deoxyribonuclease

Question 25

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 _________.

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

Question 26

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

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

Question 27

The _______ strand fragment grows away from the replication fork toward the ___ of the previously synthesized fragment to which it is subsequently linked.

A)leading, 5'-end
B)lagging, 5'-end
C)leading, 3'-end
D)lagging, 3'-end
E)lagging, N-terminal

Question 28

Which of the following is an advantage of using RNA primers during initiation of a strand in replication?

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 slows down the process of replication, which increases accuracy of complementary base pairing.
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 29

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

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

Question 30

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

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

Question 31

Where is the DnaB helicase first loaded onto the DNA?

A)at the replication terminator site
B)at the replication origin
C)at random locations through the circular chromosome
D)at the operator
E)at the promoter

Question 32

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

A)It has a 3'-hydroxyl terminus, 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 33

How does DNA polymerase III move from one site on the lagging strand template to a site closer to replication fork?

A)It hitches a ride with the DNA polymerase that is moving that way along the leading strand template.
B)It hitches a ride with the DNA polymerase that is moving that way along the lagging strand template.
C)It moves by itself like a tiny molecular motor.
D)It transports from the earlier Okazaki fragment to the later Okazaki fragment.
E)It is moved toward the replication fork by a complex of proteins called the transportosome.

Question 34

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

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 35

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

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 36

The DNA strand growing toward the replication fork grows ______ in a 5'->3' direction as the replication fork advances and is called the ________.

A)continuously, leading strand
B)discontinuously, lagging strand
C)continuously, lagging strand
D)discontinuously, leading strand
E)steadfastly, forthright strand

Question 37

Since one strand of DNA is synthesized continuously during replication and the other is made discontinuously, replication is said to be ___________.

A)continuous
B)hemicontinuous
C)discontinuous
D)semidiscontinuous
E)semicontinuous

Question 38

What happens to the RNA primers that initiate replication?

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 39

_________ are DNA unwinding enzymes that unwind the DNA in a reaction using the energy from ________ to move along one of the DNA strands, breaking the _______ holding the two strands together.

A)DNA helicases, ATP dehydration, disulfide linkages
B)DNA gyrases, ATP hydrolysis, hydrogen bonds
C)DNA helicases, ATP hydrolysis, 3'-5'-phosphodiester linkages
D)DNA helicases, ATP hydrolysis, hydrogen bonds
E)DNA gyrases, ATP dehydration, hydrogen bonds

Question 40

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

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.

Question 41

The assembly of the β clamp around the DNA requires a multisubunit _______ that is also part of the ________; part of this structure opens the ______ so that it can fit around the DNA.

A)clamp loader, polymericon, β clamp
B)clamp loader, DNA polymerase III holoenzyme, β clamp
C)DNA polymerase III holoenzyme, clamp loader, replicon
D)β clamp, DNA polymerase III holoenzyme, clamp loader
E)clamp loader, β clamp, DNA polymerase III holoenzyme

Question 42

Which side chain critical to DNA strand elongation is lacking in the nucleotide analog azidothymidine (AZT)?

A)the 5′ OH group
B)the 2′ OH group
C)the 3′ OH group
D)the triphosphate group

Question 43

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

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, to synthesize 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 44

What happens simultaneously with the removal of RNA primer by the 5'->3' exonuclease activity of DNA polymerase I?

A)The DNA double helix is unwound.
B)The gap left by the removal of the RNA primer is filled in with deoxyribonucleotides.
C)The gap left by the removal of the RNA primer is filled in with ribonucleotides.
D)DNA is supercoiled extensively.

Question 45

Which DNA polymerase in bacteria synthesizes DNA strands during replication and forms part of a complex that serves as a large replication machine?

A)DNA polymerase I
B)DNA polymerase II
C)DNA polymerase III
D)DNA polymerase IV

Question 46

Which enzyme is responsible for joining the last deoxyribonucleotide added during RNA primer digestion to the 5' end of the previously synthesized and adjacent DNA fragment?

A)DNA polymerase I
B)DNA polymerase III
C)DNA ligase
D)the holoenzyme
E)DNA gyrase

Question 47

The DNA polymerase on the leading strand template _____________.

A)stays tethered to a single β clamp during replication
B)switches from β clamp to β clamp during replication
C)cycles to a new β clamp that has been assembled at an RNA primer-DNA template junction closer to the replication fork
D)cycles to a new β clamp that has been assembled at an RNA primer-DNA template junction farther from the replication fork

Question 48

The small portions in which eukaryotic cells replicate their genomes are called _______.

A)replicants
B)replicons
C)repliants
D)replicosomes
E)tracts

Question 49

Cyclin-dependent kinase activity stays high through mitosis after rising prior to DNA synthesis. Which of the following results from its elevated activity?

A)Chromosomes decondense.
B)Formation of new prereplication complexes is suppressed.
C)Formation of new prereplication complexes is enhanced.
D)Histones are enlarged by removing their phosphate groups.
E)Histones are shrunk by binding amino groups to them.

Question 50

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

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 51

Which piece of evidence provided the best evidence that the sequence of DNA itself was unimportant in the timing of replication?

A)The inactive, heterochromatized X chromosome in female mammals replicates late in S phase, while the active euchromatic X chromosome replicates at an earlier stage.
B)The inactive, heterochromatized X chromosome in female mammals replicates early in S phase, while the active euchromatic X chromosome replicates at a later stage.
C)The inactive, heterochromatized X chromosome in female mammals replicates late in M phase, while the active euchromatic X chromosome replicates at an earlier stage.
D)Incorporation of radioactive DNA precursors in replicating cells begins over heterochromatic regions in the nucleus.
E)Incorporation of radioactive DNA precursors in replicating cells ends over heterochromatic regions in the nucleus.

Question 52

What is the average rate of DNA replication in a bacterium like E. coli?

A)about 100 nucleotides/sec
B)about 1,000 nucleotides/min
C)about 1,000 nucleotides/sec
D)about 10,000 nucleotides/sec
E)about 100 nucleotides/min

Question 53

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

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

Question 54

What is the probability that, in E. coli, an incorrect nucleotide will be incorporated into DNA during replication and remain there?

A)one in one billion nucleotides
B)one in 1000 nucleotides
C)one in four million nucleotides
D)one in 100,000 to 1,000,000 nucleotides
E)one in 10,000 nucleotides

Question 55

What technique was used to show DNA molecules are replicated simultaneously at several sites along their length?

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

Question 56

What is the name of the noncatalytic component of the DNA polymerase III holoenzyme that keeps the polymerase associated with the DNA template?

A)β-pleated sheet
B)α-helix
C)β-clamp
D)α-clamp
E)β-clam

Question 57

What is the mechanism of action of the anti-HIV drug AZT?

A)it causes double-strand DNA breaks
B)it inhibits DNA synthesis by reverse transcriptase
C)it prevents transcription in infected cells
D)it blocks the active site of DNA ligase
E)it prevents viral entry into cells

Question 58

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

A)one in one billion nucleotides
B)one in 1000 nucleotides
C)one in four million nucleotides
D)one in 100,000 to 1,000,000 nucleotides
E)one in 10,000 nucleotides

Question 59

At what stage of the eukaryotic cell cycle do key protein kinases, like cyclin-dependent kinase, become activated to allow for DNA replication initiation?

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 60

Theoretically, in the most efficient model of data storage, how many "bits" of information can be stored per nucleotide position when using DNA for data storage?

A)1
B)2
C)5
D)10

Question 61

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

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 62

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

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 63

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

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

Question 64

Which eukaryotic DNA polymerase is tightly associated with primase and responsible for Okazaki fragment synthesis initiation?

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

Question 65

Which type of DNA repair removes, via a cut-and-patch mechanism, a variety of bulky lesions, like pyrimidine dimers and nucleotides to which various chemical groups have been attached?

A)nucleotide excision repair
B)base excision repair
C)mismatch repair
D)double-strand breakage repair
E)All of these are correct.

Question 66

What is the advantage of transcription-coupled repair?

A)It prevents cells from investing energy in transcription.
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 67

Which DNA repair mechanism removes altered nucleotides generated by reactive chemicals present in the diet or produced by metabolism?

A)nucleotide excision repair
B)base excision repair
C)mismatch repair
D)double-strand breakage repair
E)the global genomic pathway

Question 68

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

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 69

What is responsible for joining eukaryotic Okazaki fragments together?

A)DNA ligase
B)DNA polymerase α
C)DNA polymerase δ
D)DNA polymerase β
E)RNase H1

Question 70

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

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

Question 71

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

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

Question 72

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

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

Question 73

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

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

Question 74

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 δ?

A)DNA polymerase α
B)DNA polymerase δ
C)DNA polymerase β
D)both DNA polymerase α and DNA polymerase β
E)RNase H1

Question 75

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

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

Question 76

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

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 77

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?

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

Question 78

After cuts are made on the two sides of the lesion in nucleotide excision repair, what holds the damaged part of the strand in position for a while before its final removal?

A)ionic bonds
B)van der Waals forces
C)hydrogen bonds
D)3'-5' phosphodiester linkages
E)disulfide linkages

Question 79

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

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

Question 80

The stepwise assembly of nucleosomes and their orderly spacing along the DNA is facilitated by __________________.

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