Question 1

Which part of the lac operon produces a regulatory protein that is trans- acting?

Accepted Answer

A)  lacO 
B)  lacI 
C)  lacZ 
D)  lacP 
E)  lacY 
A)  lacO 
B)  lacI 
C)  lacZ 
D)  lacP 
E)  lacY

Question 2

Which of the following best describes expression of the lac genes in this partial diploid? I+ P+OC Z- Y+/ I- P+ O+ Z+ Y-

Accepted Answer

A)  β- galactosidase is made both in the presence and absence of lactose, but permease is only made when lactose is present. 
B)  Both β- galactosidase and permease are not made whether lactose is present or not. 
C)  β- galactosidase is only made when lactose is present, but permease is made both in the presence and absence of lactose. 
D)  Both β- galactosidase and permease are made both in the presence of and in the absence of lactose. 
E)  Both β- galactosidase and permease are made only when lactose is present. 
A)  β- galactosidase is made both in the presence and absence of lactose, but permease is only made when lactose is present. 
B)  Both β- galactosidase and permease are not made whether lactose is present or not. 
C)  β- galactosidase is only made when lactose is present, but permease is made both in the presence and absence of lactose. 
D)  Both β- galactosidase and permease are made both in the presence of and in the absence of lactose. 
E)  Both β- galactosidase and permease are made only when lactose is present.

Question 3

Describe the differences between inducible and repressible operons. How does attenuation differ from inducible repressible operons?
Would the lac operon be active if a cell has the following food sources?
a. only lactose
b. only glucose
c. lactose and glucose

Accepted Answer

Operons like lac that are involved in ca

Question 4

What are the names of the three possible alternative stem loops that can form in mRNA?

Accepted Answer

pause, ant

Question 5

In the presence of glucose, where is the lac repressor bound?

Accepted Answer

A)  lacP 
B)  lacZ 
C)  lacO 
D)  lacI 
E)  The lac repressor is not bound to the operon. 
A)  lacP 
B)  lacZ 
C)  lacO 
D)  lacI 
E)  The lac repressor is not bound to the operon.

Question 6

In a partial diploid of the genotype I- P+ O+ Z- Y+/ I+ P- O+ Z+ Y+, synthesis of

Accepted Answer

A)  β- galactosidase will be inducible and permease will be constitutive 
B)  β- galactosidase and permease will be constitutive 
C)  β- galactosidase and permease will be uninducible 
D)  β- galactosidase will be uninducible and permease will be inducible 
E)  β- galactosidase and permease will be inducible 
A)  β- galactosidase will be inducible and permease will be constitutive 
B)  β- galactosidase and permease will be constitutive 
C)  β- galactosidase and permease will be uninducible 
D)  β- galactosidase will be uninducible and permease will be inducible 
E)  β- galactosidase and permease will be inducible

Question 7

What protein cleaves the h repressor monomers to inactivate the repressor protein, and is activated by DNA- damaging agents?

Accepted Answer

The answer of What protein cleaves the h repressor monomers...

Question 8

In the absence of tryptophan,____________ .

Accepted Answer

A)  the repressor binds the corepressor, and operon gene transcription occurs 
B)  the active repressor binds trpP, so operon gene transcription is repressed 
C)  the inducer cannot bind trpO, so operon gene transcription occurs 
D)  the inactive repressor cannot bind trpO, so operon gene transcription occurs 
E)  the active repressor cannot bind trpO, so operon gene transcription is attenuated 
A)  the repressor binds the corepressor, and operon gene transcription occurs 
B)  the active repressor binds trpP, so operon gene transcription is repressed 
C)  the inducer cannot bind trpO, so operon gene transcription occurs 
D)  the inactive repressor cannot bind trpO, so operon gene transcription occurs 
E)  the active repressor cannot bind trpO, so operon gene transcription is attenuated

Question 9

In h phage, which protein, the product of the cI gene, blocks the transcription required to initiate the lytic cycle?

Accepted Answer

A)  repressor 
B)  cro 
C)  enhancer 
D)  integrase 
E)  operator 
A)  repressor 
B)  cro 
C)  enhancer 
D)  integrase 
E)  operator

Question 10

Suppose a  λ phage infected a protease- deficient bacterial cell. Would the lytic or lysogenic life cycle be favored? Why?

Accepted Answer

The lytic cycle. Protease action is resp

Question 11

Which of these haploid strains produces permease inducibly, but does not produce β- galactosidase?

Accepted Answer

A)  I - P+ O+ Z - Y+ 
B)  I+ P+ O C Z+ Y+ 
C)  I - P+ O+ Z - Y - 
D)  I - P+ O+ Z+ Y+ 
E)  I+ P+ O+ Z - Y+ 
A)  I - P+ O+ Z - Y+ 
B)  I+ P+ O C Z+ Y+ 
C)  I - P+ O+ Z - Y - 
D)  I - P+ O+ Z+ Y+ 
E)  I+ P+ O+ Z - Y+

Question 12

Which proteins facilitate RNA polymerase binding at promoters to increase levels of transcription?

Accepted Answer

The answer of Which proteins facilitate RNA polymerase binding at...

Question 13

Disrupting the formation of which stem- loop structure of trpL would decrease the efficiency of transcriptional regulation?

Accepted Answer

A)  2- 4 (termination) stem loop 
B)  2- 3 (antitermination) stem loop 
C)  1- 3 (antitermination) stem loop 
D)  1- 2 (pause) stem loop 
E)  3- 4 (termination) stem loop 
A)  2- 4 (termination) stem loop 
B)  2- 3 (antitermination) stem loop 
C)  1- 3 (antitermination) stem loop 
D)  1- 2 (pause) stem loop 
E)  3- 4 (termination) stem loop

Question 14

Binding of which complex increases the ability of RNA polymerase to transcribe the lac
operon?

Accepted Answer

The answer of Binding of which complex increases the ability...

Question 15

During the attenuation of the trp operon, which stem loop leads to polycistronic mRNA synthesis during tryptophan starvation?

Accepted Answer

A)  1- 2 (pause) stem loop 
B)  3- 4 (termination) stem loop 
C)  1- 3 (antitermination) stem loop 
D)  2- 3 (antitermination) stem loop 
E)  2- 4 (termination) stem loop 
A)  1- 2 (pause) stem loop 
B)  3- 4 (termination) stem loop 
C)  1- 3 (antitermination) stem loop 
D)  2- 3 (antitermination) stem loop 
E)  2- 4 (termination) stem loop

Question 16

Which of the following statements regarding attenuation of the trp operon is NOT true?

Accepted Answer

A)  It is controlled by alternative folding of the mRNA synthesized from the trpL region. 
B)  If the two tryptophan codons were changed to arginine codons the operon would no longer be sensitive to tryptophan levels but would instead be sensitive to arginine levels. 
C)  Translation of a trpL coding sequence into a 14- amino acid polypeptide (including the methionine of the start codon and two back- to- back tryptophan codons) is crucial to its function. 
D)  When tryptophan levels are low, the ribosome will occupy regions 1 and 2 after completing translation of the coding sequence, regions 3 and 4 will pair, and transcription will terminate. 
E)  When tryptophan levels are high, the formation of a 3- 4 stem loop followed by the poly- U string will prevent expression of the structural genes of the operon. 
A)  It is controlled by alternative folding of the mRNA synthesized from the trpL region. 
B)  If the two tryptophan codons were changed to arginine codons the operon would no longer be sensitive to tryptophan levels but would instead be sensitive to arginine levels. 
C)  Translation of a trpL coding sequence into a 14- amino acid polypeptide (including the methionine of the start codon and two back- to- back tryptophan codons) is crucial to its function. 
D)  When tryptophan levels are low, the ribosome will occupy regions 1 and 2 after completing translation of the coding sequence, regions 3 and 4 will pair, and transcription will terminate. 
E)  When tryptophan levels are high, the formation of a 3- 4 stem loop followed by the poly- U string will prevent expression of the structural genes of the operon.

Question 17

Changing conformation at the active site as a result of binding a substance at a different site is known as___________ .

Accepted Answer

The answer of Changing conformation at the active site as...

Question 18

Which of the following mutants are noninducible?

Accepted Answer

A)  lacIS 
B)  lacOC 
C)  lacI - 
D)  lacI+ 
E)  lacO+ 
A)  lacIS 
B)  lacOC 
C)  lacI - 
D)  lacI+ 
E)  lacO+

Question 19

Northern blot analysis is performed on mRNA isolated from E. coli after growth in a glucose- only medium (lane 1) or a lactose- only medium (lane 2). The blots are hybridized with a probe for a portion of the lacZ sequence. Indicate the expected results for the following bacterial genotypes using dark, light, or no shading to i full, low, or no expression, respectively.
a. I+ P+ O+ Z+ Y+
b. I+ P- O+ Z+ Y+
c. I- P+ O+ Z+ Y+
d. I+ P+ OC Z+ Y+
e. I+ P+ O+ Z+ Y+ and a mutation of the CAP binding site preventing CAP- cAMP binding

Accepted Answer

The answer of Northern blot analysis is performed on mRNA...

Question 20

In the trp operon, what gene contains the attenuator region?

Accepted Answer

The answer of In the trp operon, what gene contains...

Which part of the lac operon produces a regulatory protein that is trans- acting?

Which of the following best describes expression of the lac genes in this partial diploid? I+ P+OC Z- Y+/ I- P+ O+ Z+ Y-

Describe the differences between inducible and repressible operons. How does attenuation differ from inducible repressible operons? Would the lac operon be active if a cell has the following food sources? a. only lactose b. only glucose c. lactose and glucose

What are the names of the three possible alternative stem loops that can form in mRNA?

In the presence of glucose, where is the lac repressor bound?

In a partial diploid of the genotype I- P+ O+ Z- Y+/ I+ P- O+ Z+ Y+, synthesis of

What protein cleaves the h repressor monomers to inactivate the repressor protein, and is activated by DNA- damaging agents?

In the absence of tryptophan,____________ .

In h phage, which protein, the product of the cI gene, blocks the transcription required to initiate the lytic cycle?

Suppose a λ phage infected a protease- deficient bacterial cell. Would the lytic or lysogenic life cycle be favored? Why?

Which of these haploid strains produces permease inducibly, but does not produce β- galactosidase?

Which proteins facilitate RNA polymerase binding at promoters to increase levels of transcription?

Disrupting the formation of which stem- loop structure of trpL would decrease the efficiency of transcriptional regulation?

Binding of which complex increases the ability of RNA polymerase to transcribe the lac operon?

During the attenuation of the trp operon, which stem loop leads to polycistronic mRNA synthesis during tryptophan starvation?

Which of the following statements regarding attenuation of the trp operon is NOT true?

Changing conformation at the active site as a result of binding a substance at a different site is known as___________ .

Which of the following mutants are noninducible?

In the trp operon, what gene contains the attenuator region?

The Molecular Basis of Heredity, Variation, and Evolution

Transmission Genetics

Cell Division and Chromosome Heredity

Inheritance Patterns of Single Genes and Gene Interaction

Genetic Linkage and Mapping in Eukaryotes

Genetic Analysis and Mapping in Bacteria and Bacteriophage

Dna Structure and Replication

Molecular Biology of Transcription and Rna Processing

The Molecular Biology of Translation

Chromosome Chapter Title Tbd

Gene Mutation, Dna Repair, and Homologous Recombination

Regulation of Gene Expression in Bacteria and Bacteriophage

Regulation of Gene Expression in Eukaryotes

Analysis of Gene Function by Forward Genetics and Reverse Genetics

Recombinant Dna Technology and Its Applications

Genomics: Genetics From a Whole-Genome Perspective

Organelle Inheritance and the Evolution of Organelle Genomes

Developmental Genetics

Genetic Analysis of Quantitative Traits

Population Genetics and Evolution at the Population, Species, and Molecular Levels

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Exam 12: Chromosome Exam Title Tbd

Which part of the lac operon produces a regulatory protein that is trans- acting?

Which of the following best describes expression of the lac genes in this partial diploid? I+ P+OC Z- Y+/ I- P+ O+ Z+ Y-

Describe the differences between inducible and repressible operons. How does attenuation differ from inducible repressible operons? Would the lac operon be active if a cell has the following food sources? a. only lactose b. only glucose c. lactose and glucose

What are the names of the three possible alternative stem loops that can form in mRNA?

In the presence of glucose, where is the lac repressor bound?

In a partial diploid of the genotype I- P+ O+ Z- Y+/ I+ P- O+ Z+ Y+, synthesis of

What protein cleaves the h repressor monomers to inactivate the repressor protein, and is activated by DNA- damaging agents?

In the absence of tryptophan,____________ .

In h phage, which protein, the product of the cI gene, blocks the transcription required to initiate the lytic cycle?

Suppose a λ phage infected a protease- deficient bacterial cell. Would the lytic or lysogenic life cycle be favored? Why?

Which of these haploid strains produces permease inducibly, but does not produce β- galactosidase?

Which proteins facilitate RNA polymerase binding at promoters to increase levels of transcription?

Disrupting the formation of which stem- loop structure of trpL would decrease the efficiency of transcriptional regulation?

Binding of which complex increases the ability of RNA polymerase to transcribe the lac operon?

During the attenuation of the trp operon, which stem loop leads to polycistronic mRNA synthesis during tryptophan starvation?

Which of the following statements regarding attenuation of the trp operon is NOT true?

Changing conformation at the active site as a result of binding a substance at a different site is known as___________ .

Which of the following mutants are noninducible?

In the trp operon, what gene contains the attenuator region?

The Molecular Basis of Heredity, Variation, and Evolution

Transmission Genetics

Cell Division and Chromosome Heredity

Inheritance Patterns of Single Genes and Gene Interaction

Genetic Linkage and Mapping in Eukaryotes

Genetic Analysis and Mapping in Bacteria and Bacteriophage

Dna Structure and Replication

Molecular Biology of Transcription and Rna Processing

The Molecular Biology of Translation

Chromosome Chapter Title Tbd

Gene Mutation, Dna Repair, and Homologous Recombination

Regulation of Gene Expression in Bacteria and Bacteriophage

Regulation of Gene Expression in Eukaryotes

Analysis of Gene Function by Forward Genetics and Reverse Genetics

Recombinant Dna Technology and Its Applications

Genomics: Genetics From a Whole-Genome Perspective

Organelle Inheritance and the Evolution of Organelle Genomes

Developmental Genetics

Genetic Analysis of Quantitative Traits

Population Genetics and Evolution at the Population, Species, and Molecular Levels

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