Question 1

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

Accepted Answer

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. 
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 2

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

Question 3

You are studying replication in a particular bacterial strain.At 37°C,the bacteria appear perfectly normal.If the temperature is raised to 43°C,however,they stop growing and are unable to replicate their DNA.If some of them are placed back at 37°C,they begin to replicate their DNA and are again perfectly normal.What is wrong?

Accepted Answer

The bacteria probably carry a

Question 4

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. 
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 5

If cells are given a very short exposure (pulses)to radioactive DNA nucleotide precursors,where is most of the radiolabel located?

Accepted Answer

A) in the cytoplasm 
B) associated with the nuclear matrix 
C) in the mitochondria 
D) in the DNA loops surrounding the nuclear matrix 
E) in the mesosome 
A) in the cytoplasm 
B) associated with the nuclear matrix 
C) in the mitochondria 
D) in the DNA loops surrounding the nuclear matrix 
E) in the mesosome

Question 6

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

Accepted Answer

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

Question 7

The assembly of the$\beta$ 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.

Accepted Answer

A) clamp loader,polymericon,$\beta$ clamp 
B) clamp loader,DNA polymerase III holoenzyme,$\beta$clamp 
C) DNA polymerase III holoenzyme,clamp loader,replicon 
D) $\beta$ clamp,DNA polymerase III holoenzyme,clamp loader 
E) clamp loader,$\beta$ clamp,DNA polymerase III holoenzyme 
A) clamp loader,polymericon,$\beta$ clamp 
B) clamp loader,DNA polymerase III holoenzyme,$\beta$clamp 
C) DNA polymerase III holoenzyme,clamp loader,replicon 
D) $\beta$ clamp,DNA polymerase III holoenzyme,clamp loader 
E) clamp loader,$\beta$ clamp,DNA polymerase III holoenzyme

Question 8

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

Question 9

What enzyme activity are the Mcm proteins (Mcm2 - Mcm7)thought to exhibit once they have been loaded onto the replication origin and associated into a ring-shaped complex? What role does this enzyme activity play in replication and to what protein in E.coli is it analogous?

Accepted Answer

Helicase activity.The helicase

Question 10

Where is the DnaB helicase first loaded onto the DNA?

Accepted Answer

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 
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 11

Patients with the classical form of xeroderma pigmentosum have a defect in one of the genes involved in ______________.

Accepted Answer

A) nucleotide excision repair 
B) replication 
C) base excision repair 
D) transcription 
E) base excitation repair 
A) nucleotide excision repair 
B) replication 
C) base excision repair 
D) transcription 
E) base excitation repair

Question 12

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

Accepted Answer

A) All of the DNA is made of 2 "light" strands. 
B) Half of the DNA is made of 2 "light" strands and half of the DNA is made of 1 "light" strand and 1 "heavy" strand. 
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) 75% of the DNA is made of 2 "light" strands and 25% of the DNA is made of 2 "heavy" strands. 
A) All of the DNA is made of 2 "light" strands. 
B) Half of the DNA is made of 2 "light" strands and half of the DNA is made of 1 "light" strand and 1 "heavy" strand. 
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) 75% of the DNA is made of 2 "light" strands and 25% of the DNA is made of 2 "heavy" strands.

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

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

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

If cells are given a very short exposure (pulses)to radioactive DNA nucleotide precursors,where is most of the radiolabel located?

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

The assembly of the $\beta$ 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.

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

What enzyme activity are the Mcm proteins (Mcm2 - Mcm7)thought to exhibit once they have been loaded onto the replication origin and associated into a ring-shaped complex? What role does this enzyme activity play in replication and to what protein in E.coli is it analogous?

Where is the DnaB helicase first loaded onto the DNA?

Patients with the classical form of xeroderma pigmentosum have a defect in one of the genes involved in ______________.

Introduction to the Study of Cell and Molecular Biology

The Chemical Basis of Life

Bioenergetics, Enzymes, and Metabolism

The Structure and Function of the Plasma Membrane

Aerobic Respiration and the Mitochondrion

Photosynthesis and the Chloroplast

Interactions Between Cells and Their Environment

Cytoplasmic Membrane Systems: Structure, Function, and Membrane Trafficking

The Cytoskeleton and Cell Motility

The Nature of the Gene and the Genome

Gene Expression: From Transcription to Translation

Control of Gene Expression

Cellular Reproduction

Cell Signaling and Signal Transduction: Communication Between Cells

Cancer

The Immune Response

Techniques in Cell and Molecular Biology

Filters

Exam 13: Dna Replication and Repair

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

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

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

If cells are given a very short exposure (pulses)to radioactive DNA nucleotide precursors,where is most of the radiolabel located?

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

The assembly of the β\betaβ 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.

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

What enzyme activity are the Mcm proteins (Mcm2 - Mcm7)thought to exhibit once they have been loaded onto the replication origin and associated into a ring-shaped complex? What role does this enzyme activity play in replication and to what protein in E.coli is it analogous?

Where is the DnaB helicase first loaded onto the DNA?

Patients with the classical form of xeroderma pigmentosum have a defect in one of the genes involved in ______________.

Introduction to the Study of Cell and Molecular Biology

The Chemical Basis of Life

Bioenergetics, Enzymes, and Metabolism

The Structure and Function of the Plasma Membrane

Aerobic Respiration and the Mitochondrion

Photosynthesis and the Chloroplast

Interactions Between Cells and Their Environment

Cytoplasmic Membrane Systems: Structure, Function, and Membrane Trafficking

The Cytoskeleton and Cell Motility

The Nature of the Gene and the Genome

Gene Expression: From Transcription to Translation

Control of Gene Expression

Cellular Reproduction

Cell Signaling and Signal Transduction: Communication Between Cells

Cancer

The Immune Response

Techniques in Cell and Molecular Biology

Filters

The assembly of the $\beta$ 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.