Question 1

Which of the following typically only have one origin of replication?

Accepted Answer

A)  humans 
B)  prokaryotes 
C)  eukaryotes 
D)  linear model of replication 
E)  plants 
A)  humans 
B)  prokaryotes 
C)  eukaryotes 
D)  linear model of replication 
E)  plants

Question 2

What is the function of single-strand-binding proteins?

Accepted Answer

A)  connect Okazaki fragments by sealing nicks in the sugar-phosphate backbone 
B)  unwind the double helix by breaking the hydrogen bonding between the two strands at the replication fork 
C)  reduce the torsional strain that builds up ahead of the replication fork as a result of unwinding 
D)  bind to oriC and cause a short section of DNA to unwind 
E)  prevent the formation of secondary structures within single-stranded DNA 
A)  connect Okazaki fragments by sealing nicks in the sugar-phosphate backbone 
B)  unwind the double helix by breaking the hydrogen bonding between the two strands at the replication fork 
C)  reduce the torsional strain that builds up ahead of the replication fork as a result of unwinding 
D)  bind to oriC and cause a short section of DNA to unwind 
E)  prevent the formation of secondary structures within single-stranded DNA

Question 3

Which of the following statements BEST describes heteroduplex DNA?

Accepted Answer

A)  A single-stranded DNA molecule of one chromosome pairs with a single-stranded DNA molecule of another chromosome. 
B)  A single-stranded DNA molecule of one chromosome pairs with a single-stranded RNA molecule of another chromosome. 
C)  Heteroduplex DNA consists of sequences from two different species that are brought together through homologous recombination. 
D)  Heteroduplex DNA consists of an RNA primer and newly synthesized DNA on the lagging strand. 
E)  In heteroduplex DNA newly synthesized DNA has yet to be reassembled into nucleosomes. 
A)  A single-stranded DNA molecule of one chromosome pairs with a single-stranded DNA molecule of another chromosome. 
B)  A single-stranded DNA molecule of one chromosome pairs with a single-stranded RNA molecule of another chromosome. 
C)  Heteroduplex DNA consists of sequences from two different species that are brought together through homologous recombination. 
D)  Heteroduplex DNA consists of an RNA primer and newly synthesized DNA on the lagging strand. 
E)  In heteroduplex DNA newly synthesized DNA has yet to be reassembled into nucleosomes.

Question 4

Why do eukaryotic chromosomes have multiple origins of replication, whereas prokaryotic chromosomes typically have only one origin?

Accepted Answer

Eukaryotic chromosomes have multiple ori

Question 5

Which of the following eukaryotic DNA polymerases and their role is INCORRECTLY paired?

Accepted Answer

A)  $\delta$ (delta); lagging strand synthesis of nuclear DNA 
B)  $\varepsilon$ (epsilon); translesion DNA synthesis 
C) $ \eta $ (eta); translesion DNA synthesis 
D) $\gamma$ (gamma); replication and repair of mitochondrial DNA 
E) $\theta$ (theta); DNA repair 
A)  $\delta$ (delta); lagging strand synthesis of nuclear DNA 
B)  $\varepsilon$ (epsilon); translesion DNA synthesis 
C) $ \eta $ (eta); translesion DNA synthesis 
D) $\gamma$ (gamma); replication and repair of mitochondrial DNA 
E) $\theta$ (theta); DNA repair

Question 6

DNA polymerase I and DNA polymerase III both have _____ activity but only DNA polymerase I has _____ activity.

Accepted Answer

A)  5' $\rightarrow$3'exonuclease; 3'$\rightarrow$ 5' exonuclease 
B)  5' $\rightarrow$3' polymerase; 3'$\rightarrow$5' polymerase 
C)  3' $\rightarrow$ 5' polymerase; 5' $\rightarrow$3' polymerase 
D)  3' $\rightarrow$ 5' exonuclease; 5' $\rightarrow$3 ' exonuclease 
E)  5' $\rightarrow$ 3' polymerase; 3' $\rightarrow$ 5' exonuclease 
A)  5' $\rightarrow$3'exonuclease; 3'$\rightarrow$ 5' exonuclease 
B)  5' $\rightarrow$3' polymerase; 3'$\rightarrow$5' polymerase 
C)  3' $\rightarrow$ 5' polymerase; 5' $\rightarrow$3' polymerase 
D)  3' $\rightarrow$ 5' exonuclease; 5' $\rightarrow$3 ' exonuclease 
E)  5' $\rightarrow$ 3' polymerase; 3' $\rightarrow$ 5' exonuclease

Question 7

Telomerase activity is MOST likely to be found in which cells in humans?

Accepted Answer

A)  red blood cells 
B)  muscle cells 
C)  neurons 
D)  germ line 
E)  any type of somatic cell 
A)  red blood cells 
B)  muscle cells 
C)  neurons 
D)  germ line 
E)  any type of somatic cell

Question 8

Which one of the following statements is NOT true for all E. coli DNA polymerases?

Accepted Answer

A)  They require a primer to initiate synthesis. 
B)  They use dNTPs to synthesize new DNA. 
C)  They produce newly synthesized strands that are complementary and antiparallel to the template strands. 
D)  They possess 5' $\rightarrow$ 3'exonuclease activity. 
E)  They synthesize in the 5'$\rightarrow$3'direction by adding nucleotides to a 3'OH group. 
A)  They require a primer to initiate synthesis. 
B)  They use dNTPs to synthesize new DNA. 
C)  They produce newly synthesized strands that are complementary and antiparallel to the template strands. 
D)  They possess 5' $\rightarrow$ 3'exonuclease activity. 
E)  They synthesize in the 5'$\rightarrow$3'direction by adding nucleotides to a 3'OH group.

Question 9

You learn that a Mars lander has retrieved a bacterial sample from the polar ice caps. You obtain a sample of these bacteria and perform the same kind of experiment that Meselson and Stahl did to determine how the Mars bacteria replicate their DNA. Based on the following equilibrium density gradient centrifugation results, what type of replication would you propose for these new bacteria?

Accepted Answer

A)  conservative 
B)  semiconservative 
C)  dispersive 
D)  semiconservative or dispersive 
E)  conservative or dispersive 
A)  conservative 
B)  semiconservative 
C)  dispersive 
D)  semiconservative or dispersive 
E)  conservative or dispersive

Question 10

Telomerase uses _____ to synthesize new DNA.

Accepted Answer

A)  exonuclease activity 
B)  a licensing factor 
C)  strand invasion 
D)  a DNA template 
E)  an RNA template 
A)  exonuclease activity 
B)  a licensing factor 
C)  strand invasion 
D)  a DNA template 
E)  an RNA template

Question 11

Why did the Meselson and Stahl experiment require two rounds of replication?

Accepted Answer

The Meselson and Stahl experiment, condu

Question 12

List and describe the key events of DNA replication in their relative order for E. coli.

Accepted Answer

Sure! The key events of DNA replication

Question 13

Suppose Meselson and Stahl had obtained the following results in their experiment. These results would be consistent with which model of replication?

Accepted Answer

A)  conservative replication only 
B)  semiconservative and conservative replication 
C)  semiconservative replication only 
D)  dispersive replication only 
E)  semiconservative and dispersive replication 
A)  conservative replication only 
B)  semiconservative and conservative replication 
C)  semiconservative replication only 
D)  dispersive replication only 
E)  semiconservative and dispersive replication

Question 14

DNA polymerases require all of the following for DNA replication EXCEPT:

Accepted Answer

A)  a DNA template. 
B)  a primer. 
C)  free 3' OH. 
D)  3' to 5' polymerase activity. 
E)  dNTPs. 
A)  a DNA template. 
B)  a primer. 
C)  free 3' OH. 
D)  3' to 5' polymerase activity. 
E)  dNTPs.

Question 15

What does "proofreading" refer to with regard to DNA replication?

Accepted Answer

Proofreading refers to the mechanism by

Question 16

Explain the need for and mechanism of licensing of DNA replication.

Accepted Answer

The need for licensing of DNA replicatio

Question 17

In the diagram below, the arrow indicates the direction of movement of a replication fork.   a. Which strand, top or bottom, is the leading strand? Explain.
b. On which strand, top or bottom, would you expect to find Okazaki fragments? Explain.

Accepted Answer

The answer of In the diagram below, the arrow indicates...

Question 18

For which of the following is the "end-replication problem" relevant?

Accepted Answer

A)  circular DNA 
B)  linear chromosomes 
C)  the centromere region of a chromosome 
D)  rolling-circle model of replication 
E)  theta model of replication 
A)  circular DNA 
B)  linear chromosomes 
C)  the centromere region of a chromosome 
D)  rolling-circle model of replication 
E)  theta model of replication

Question 19

Which of the following statements explaining the mechanism of action of telomerase is correct? (Select all that apply.)

Accepted Answer

A)  The extension of telomeres via telomerase occurs at the 3ʹ overhang with a G-rich sequence. 
B)  Telomerase carries a short single-stranded DNA component that is used as a template to extend the telomere. 
C)  The extension of telomeres via telomerase occurs at the 5ʹ end, where DNA polymerase cannot add a new deoxynucldotide after the removal of the very last RNA primer. 
D)  The extension at the 3ʹ overhang is followed by the extension of 5ʹ complementary strand via a currently unknown mechanism. 
E)  Telomerase finishes complementary base pairing of the 5ʹ complementary strand. 
A)  The extension of telomeres via telomerase occurs at the 3ʹ overhang with a G-rich sequence. 
B)  Telomerase carries a short single-stranded DNA component that is used as a template to extend the telomere. 
C)  The extension of telomeres via telomerase occurs at the 5ʹ end, where DNA polymerase cannot add a new deoxynucldotide after the removal of the very last RNA primer. 
D)  The extension at the 3ʹ overhang is followed by the extension of 5ʹ complementary strand via a currently unknown mechanism. 
E)  Telomerase finishes complementary base pairing of the 5ʹ complementary strand.

Question 20

The diagram shown below is one half of a replication bubble. As the DNA template strands unwind towards the right, new strands of DNA get synthesized. Which of the following represents a lagging strand?

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  D 
E)  There is no lagging strand in this diagram. 
A)  A 
B)  B 
C)  C 
D)  D 
E)  There is no lagging strand in this diagram.

Exam 12: DNA Replication and Recombination

Which of the following typically only have one origin of replication?

What is the function of single-strand-binding proteins?

Which of the following statements BEST describes heteroduplex DNA?

Why do eukaryotic chromosomes have multiple origins of replication, whereas prokaryotic chromosomes typically have only one origin?

Which of the following eukaryotic DNA polymerases and their role is INCORRECTLY paired?

DNA polymerase I and DNA polymerase III both have _____ activity but only DNA polymerase I has _____ activity.

Telomerase activity is MOST likely to be found in which cells in humans?

Which one of the following statements is NOT true for all E. coli DNA polymerases?

Telomerase uses _____ to synthesize new DNA.

Why did the Meselson and Stahl experiment require two rounds of replication?

List and describe the key events of DNA replication in their relative order for E. coli.

Suppose Meselson and Stahl had obtained the following results in their experiment. These results would be consistent with which model of replication?

DNA polymerases require all of the following for DNA replication EXCEPT:

What does "proofreading" refer to with regard to DNA replication?

Explain the need for and mechanism of licensing of DNA replication.

In the diagram below, the arrow indicates the direction of movement of a replication fork. a. Which strand, top or bottom, is the leading strand? Explain. b. On which strand, top or bottom, would you expect to find Okazaki fragments? Explain.

For which of the following is the "end-replication problem" relevant?

Which of the following statements explaining the mechanism of action of telomerase is correct? (Select all that apply.)

The diagram shown below is one half of a replication bubble. As the DNA template strands unwind towards the right, new strands of DNA get synthesized. Which of the following represents a lagging strand?

Introduction to Genetics

Chromosomes and Cellular Reproduction

Basic Principles of Heredity

Sex Determination and Sex-Linked Characteristics

Extensions and Modifications of Basic Principles

Pedigree Analysis, Applications, and Genetic Testing

Linkage, Recombination, and Eukaryotic Gene Mapping

Chromosome Variation

Bacterial and Viral Genetic Systems

DNA: the Chemical Nature of the Gene

Chromosome Structure and Organelle Dna

Transcription

Rna Molecules and Rna Processing

The Genetic Code and Translation

Control of Gene Expression in Prokaryotes

Control of Gene Expression in Eukaryotes

Gene Mutations and Dna Repair

Molecular Genetic Analysis and Biotechnology

Genomics and Proteomics

Epigenetics

Developmental Genetics and Immunogenetics

Cancer Genetics

Quantitative Genetics

Population Genetics

Evolutionary Genetics

Filters

DNA polymerase I and DNA polymerase III both have _ activity but only DNA polymerase I has _ activity.