Question 1

Based on current research,quorum sensing has only been shown to occur in bioluminescent bacteria.

Accepted Answer

A) True 
 B)False

Question 2

The type of regulation that relies on a critical cell density is called ______ _______.

Accepted Answer

The answer of The type of regulation that relies on...

Question 3

Which of these is required for transcription that is regulated by positive control?

Accepted Answer

A)   activator protein
B)   repressor protein
C)   inducer protein
D)   attenuator protein
E)   DNA polymerase.

Question 4

How does lactose regulate the expression of the lac operon?

Accepted Answer

The lactose regulation of the lac operon...

Question 5

A mutation in the lacI gene results in an active repressor protein that can no longer bind allolactose.Which would be true of the phenotype of the mutant strain?

Accepted Answer

A)   It would be constitutive for β-galactosidase expression.
B)   It would overexpress LacZ.
C)   It would be the same as the wild-type strain.
D)   It would repress β-galactosidase when lactose is present.
E)   It would be overexpress β-galactosidase when lactose is present.

Question 6

The directed movement toward a light source is called ______________.

Accepted Answer

The answer of The directed movement toward a light source...

Question 7

What would characterize the phenotype of a CheY mutant?

Accepted Answer

A)   Loss of motility.
B)   Constant tumbling.
C)   Smooth swimming.
D)   Inability to sense certain chemicals.
E)   Movement toward repellents and away from attractants. C

Question 8

Which of these controls the expression of the lac operon?

Accepted Answer

A)   An activator protein only.
B)   An attenuation mechanism.
C)   A repressor protein only.
D)   Both repression and activation mechanisms.
E)   Both repression and attenuation mechanisms. D

Question 9

What does sigma factor helps the RNA polymerase do?

Accepted Answer

A)   Assemble tRNA subunits.
B)   Bind to activator proteins.
C)   Attach the ribosomal subunits.
D)   Identify the promoter region of a gene.
E)   Release from the transcribed DNA. D

Question 10

During negative regulation of gene expression the repressor protein binds to the operator to inhibit transcription.What is the effector molecule that controls the activity of the repressor protein called?

Accepted Answer

A)   corepressor
B)   inducer
C)   activator
D)   corepressor or inducer
E)   corepressor or activator

Question 11

Give example of genes that are usually expressed constitutively.Why are these genes constitutively expressed?

Accepted Answer

Constitutive gene expression refers to g...

Question 12

Isopropyl β-d-1- thiogalactopyranoside (IPTG) ,a lactose analog,acts as an inducer of the lac operon.What is its mode of action?

Accepted Answer

A)   It functions as a co-activator of gene expression.
B)   It inactivates the LacI repressor protein.
C)   It activates the enzyme β-galactosidase.
D)   It binds the RNAP for enhanced binding to the promoter.
E)   It binds to the operator to enhance transcription initiation.

Question 13

The enzyme β-galactosidase hydrolyzes lactose to glucose and fructose.

Accepted Answer

A) True 
 B)False

Question 14

What is quorum sensing? How is it involved in the bioluminescence of the bacterium Vibrio fischeri?

Accepted Answer

Quorum sensing is a process used by bact...

Question 15

The expression of genes required for biofilm formation occurs only after a cell has attached to a surface that is suitable for biofilm development.What is this type of gene expression called?

Accepted Answer

A)   attenuation
B)   feedback inhibition
C)   induction
D)   repression
E)   inhibition

Question 16

The two-component regulatory systems uses a _______ ________ and a response regulator.

Accepted Answer

The answer of The two-component regulatory systems uses a _______...

Question 17

What is an effector molecule?

Accepted Answer

A)   A protein that binds to an operator region of a gene.
B)   An activator protein for gene expression.
C)   A small RNA molecule that inhibits translation of mRNA.
D)   A small molecule that binds to an enzyme to regulate its activity.
E)   A small molecule that binds to the operator region of a gene.

Question 18

The transfer of T-DNA into a plant cell by Agrobacterium tumefaciens is a highly regulated process.This process only occurs if a plant becomes wounded and excretes various compounds that are detected by A.tumefaciens for expression of its virulence genes.Regulation of virulence gene expression is under the control of which type of system?

Accepted Answer

A)   A two-component system.
B)   An inducer/repressor system.
C)   An activator/co-activator system.
D)   A co-repressor/repressor system.
E)   A repressor/co-activator system.

Question 19

What is the function of methyl-accepting chemotaxis proteins (MCPs) ?

Accepted Answer

A)   To phosphorylate CheY.
B)   To control the direction of flagellar rotation.
C)   To dephosphorylate CheY.
D)   To sense the presence of a specific chemical.
E)   To drive the flagellum motors.

Question 20

The catabolite activator protein (CAP) activates transcription of the lac operon when it binds this coactivator.

Accepted Answer

A)   lactose
B)   glucose
C)   cyclic-AMP
D)   ATP
E)   allolactose

Exam 11: Regulation of Gene Expression

Based on current research,quorum sensing has only been shown to occur in bioluminescent bacteria.

Correct Answer
verified

The type of regulation that relies on a critical cell density is called _.

Correct Answer
verified

Which of these is required for transcription that is regulated by positive control?

Correct Answer
verified

How does lactose regulate the expression of the lac operon?

Correct Answer
Answered by ExamLex AI
The lactose regulation of the lac operon...
View Answer

A mutation in the lacI gene results in an active repressor protein that can no longer bind allolactose.Which would be true of the phenotype of the mutant strain?

Correct Answer
verified

The directed movement toward a light source is called ______________.

Correct Answer
verified

What would characterize the phenotype of a CheY mutant?

Correct Answer
verified
C

Which of these controls the expression of the lac operon?

Correct Answer
verified
D

What does sigma factor helps the RNA polymerase do?

Correct Answer
verified
D

During negative regulation of gene expression the repressor protein binds to the operator to inhibit transcription.What is the effector molecule that controls the activity of the repressor protein called?

Correct Answer
verified

Give example of genes that are usually expressed constitutively.Why are these genes constitutively expressed?

Correct Answer
Answered by ExamLex AI
Constitutive gene expression refers to g...
View Answer

Isopropyl β-d-1- thiogalactopyranoside (IPTG) ,a lactose analog,acts as an inducer of the lac operon.What is its mode of action?

Correct Answer
verified

The enzyme β-galactosidase hydrolyzes lactose to glucose and fructose.

Correct Answer
verified

What is quorum sensing? How is it involved in the bioluminescence of the bacterium Vibrio fischeri?

Correct Answer
Answered by ExamLex AI
Quorum sensing is a process used by bact...
View Answer

The expression of genes required for biofilm formation occurs only after a cell has attached to a surface that is suitable for biofilm development.What is this type of gene expression called?

Correct Answer
verified

The two-component regulatory systems uses a _ __ and a response regulator.

Correct Answer
verified

What is an effector molecule?

Correct Answer
verified

Correct Answer
verified

What is the function of methyl-accepting chemotaxis proteins (MCPs) ?

Correct Answer
verified

The catabolite activator protein (CAP) activates transcription of the lac operon when it binds this coactivator.

Correct Answer
verified

Exam 11: Regulation of Gene Expression

Based on current research,quorum sensing has only been shown to occur in bioluminescent bacteria.

Correct AnswerverifiedShow Answer

The type of regulation that relies on a critical cell density is called ______ _______.

Correct AnswerverifiedShow Answer

Which of these is required for transcription that is regulated by positive control?

Correct AnswerverifiedShow Answer

How does lactose regulate the expression of the lac operon?

Correct AnswerAnswered by ExamLex AIThe lactose regulation of the lac operon...View AnswerShow Answer

A mutation in the lacI gene results in an active repressor protein that can no longer bind allolactose.Which would be true of the phenotype of the mutant strain?

Correct AnswerverifiedShow Answer

The directed movement toward a light source is called ______________.

Correct AnswerverifiedShow Answer

What would characterize the phenotype of a CheY mutant?

Correct AnswerverifiedC

Which of these controls the expression of the lac operon?

Correct AnswerverifiedD

What does sigma factor helps the RNA polymerase do?

Correct AnswerverifiedD

During negative regulation of gene expression the repressor protein binds to the operator to inhibit transcription.What is the effector molecule that controls the activity of the repressor protein called?

Correct AnswerverifiedShow Answer

Give example of genes that are usually expressed constitutively.Why are these genes constitutively expressed?

Correct AnswerAnswered by ExamLex AIConstitutive gene expression refers to g...View AnswerShow Answer

Isopropyl β-d-1- thiogalactopyranoside (IPTG) ,a lactose analog,acts as an inducer of the lac operon.What is its mode of action?

Correct AnswerverifiedShow Answer

The enzyme β-galactosidase hydrolyzes lactose to glucose and fructose.

Correct AnswerverifiedShow Answer

What is quorum sensing? How is it involved in the bioluminescence of the bacterium Vibrio fischeri?

Correct AnswerAnswered by ExamLex AIQuorum sensing is a process used by bact...View AnswerShow Answer

The expression of genes required for biofilm formation occurs only after a cell has attached to a surface that is suitable for biofilm development.What is this type of gene expression called?

Correct AnswerverifiedShow Answer

The two-component regulatory systems uses a _______ ________ and a response regulator.

Correct AnswerverifiedShow Answer

What is an effector molecule?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

What is the function of methyl-accepting chemotaxis proteins (MCPs) ?

Correct AnswerverifiedShow Answer

The catabolite activator protein (CAP) activates transcription of the lac operon when it binds this coactivator.

Correct AnswerverifiedShow Answer

Correct Answer
verified

The type of regulation that relies on a critical cell density is called _.

Correct Answer
verified

Correct Answer
verified

Correct Answer
Answered by ExamLex AI
The lactose regulation of the lac operon...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
C

Correct Answer
verified
D

Correct Answer
verified
D

Correct Answer
verified

Correct Answer
Answered by ExamLex AI
Constitutive gene expression refers to g...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
Answered by ExamLex AI
Quorum sensing is a process used by bact...
View Answer

Correct Answer
verified

The two-component regulatory systems uses a _ __ and a response regulator.

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified