Question 1

In the lac operon,the operator is an example of a trans-effect genetic regulation.

Accepted Answer

A) True 
 B)False

Question 2

What is the gene responsible for attenuation in the trp operon?

Accepted Answer

A)  trpL 
B)  trpR 
C)  trpD 
D)  trpC 
A)  trpL 
B)  trpR 
C)  trpD 
D)  trpC

Question 3

In the E.coli riboswitch,mRNA gets translated when TPP is low.

Accepted Answer

A) True 
 B)False

Question 4

Because it stabilizes mRNA, antisense RNA enhances translation.

Accepted Answer

A) True 
 B)False

Question 5

A riboswitch is an RNA molecule that can exist in two different conformations.Conversion from one to another is due to the binding of a small molecule to the riboswitch.

Accepted Answer

A) True 
 B)False

Question 6

Allosteric regulation is accomplished by

Accepted Answer

A)  a small molecule that fits into an enzyme's active site. 
B)  a large protein that blocks an enzyme's active site. 
C)  a small molecule that fits into a site on the enzyme that is not the active site. 
D)  a small molecule that covalently modifies a site on the enzyme that is not the active site. 
A)  a small molecule that fits into an enzyme's active site. 
B)  a large protein that blocks an enzyme's active site. 
C)  a small molecule that fits into a site on the enzyme that is not the active site. 
D)  a small molecule that covalently modifies a site on the enzyme that is not the active site.

Question 7

The term enzyme adaptation is used to describe an enzyme that appears in a living cell following exposure to a specific substrate.

Accepted Answer

A) True 
 B)False

Question 8

Repressor proteins are responsible for negative transcriptional regulation.

Accepted Answer

A) True 
 B)False

Question 9

What would be the result if the U-rich sequence after the fourth stem loop in the trp operon was replaced by a UG-rich sequence?

Accepted Answer

A)  Attenuation would occur if tryptophan was high. 
B)  Attenuation would occur if tryptophan is low. 
C)  Attenuation would not occur if tryptophan was high. 
D)  None of the answers are correct. 
A)  Attenuation would occur if tryptophan was high. 
B)  Attenuation would occur if tryptophan is low. 
C)  Attenuation would not occur if tryptophan was high. 
D)  None of the answers are correct.

Question 10

What stem-loop conformations favor attenuation in the trp operon?

Accepted Answer

A)  1-2 
B)  1-2 and 2-3 
C)  2-3 
D)  1-2 and 3-4 
A)  1-2 
B)  1-2 and 2-3 
C)  2-3 
D)  1-2 and 3-4

Question 11

The lac operon is under what type of control?

Accepted Answer

A)  positive control 
B)  negative control 
C)  The gene would be expressed constitutively. 
D)  It depends on what the gene encodes. 
A)  positive control 
B)  negative control 
C)  The gene would be expressed constitutively. 
D)  It depends on what the gene encodes.

Question 12

Negative transcriptional regulation is conducted by activator proteins.

Accepted Answer

A) True 
 B)False

Question 13

CAP affects which operon(s)?

Accepted Answer

A)  the lac operon 
B)  the trp operon 
C)  both the lac and the trp operon 
D)  neither the lac nor the trp operon 
A)  the lac operon 
B)  the trp operon 
C)  both the lac and the trp operon 
D)  neither the lac nor the trp operon

Question 14

In Jacob,Monod,and Pardee's experiment,how many functional copies of lacI were there in the merozygote?

Accepted Answer

A)  0 
B)  1 
C)  2 
D)  3 
A)  0 
B)  1 
C)  2 
D)  3

Question 15

Which of the following is found in an operon?

Accepted Answer

A)  promoter 
B)  terminator 
C)  two or more genes 
D)  operator 
E)  All of the answers are correct. 
A)  promoter 
B)  terminator 
C)  two or more genes 
D)  operator 
E)  All of the answers are correct.

Question 16

Constitutive genes are those that have constant levels of expression.

Accepted Answer

A) True 
 B)False

Question 17

Regulation of gene expression may occur at which of the following levels?

Accepted Answer

A)  transcription 
B)  translation 
C)  posttranslation 
D)  All of the answers are correct. 
A)  transcription 
B)  translation 
C)  posttranslation 
D)  All of the answers are correct.

Exam 16: Gene Regulation in Bacteria

In the lac operon,the operator is an example of a trans-effect genetic regulation.

What is the gene responsible for attenuation in the trp operon?

In the E.coli riboswitch,mRNA gets translated when TPP is low.

Because it stabilizes mRNA, antisense RNA enhances translation.

A riboswitch is an RNA molecule that can exist in two different conformations.Conversion from one to another is due to the binding of a small molecule to the riboswitch.

Allosteric regulation is accomplished by

The term enzyme adaptation is used to describe an enzyme that appears in a living cell following exposure to a specific substrate.

Repressor proteins are responsible for negative transcriptional regulation.

What would be the result if the U-rich sequence after the fourth stem loop in the trp operon was replaced by a UG-rich sequence?

What stem-loop conformations favor attenuation in the trp operon?

The lac operon is under what type of control?

Negative transcriptional regulation is conducted by activator proteins.

CAP affects which operon(s)?

In Jacob,Monod,and Pardee's experiment,how many functional copies of lacI were there in the merozygote?

Which of the following is found in an operon?

Constitutive genes are those that have constant levels of expression.

Regulation of gene expression may occur at which of the following levels?

Overview of Genetics

Reproduction and Chromosome Transmission

Mendelian Inheritance

Sex Determination and Sex Chromosomes

Extensions of Mendelian Inheritance

Extranuclear Inheritance, Imprinting, and Maternal Effect

Genetic Linkage and Mapping in Eukaryotes

Variation in Chromosome Structure and Number

Genetics in Bacteria

Genetics of Viruses

Molecular Structure of DNA and RNA

Molecular Structure of Chromosomes and Transposition

Dna Replication and Recombination

Gene Transcription and RNA Modification

Translation of MRNA

Gene Regulation in Eukaryotes

Non-Coding Rnas

Gene Mutation and DNA Repair

Molecular Technologies

Genomics

Medical Genetics and Cancer

Population Genetics

Quantitative Genetics

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