Question 1

The scientists who proposed the operon theory are

Accepted Answer

A)  Monod and Jacob. 
B)  Watson and Crick. 
C)  Hardy and Weinberg. 
D)  Darwin and Mendel. 
E)  Hershey and Chase. 
A)  Monod and Jacob. 
B)  Watson and Crick. 
C)  Hardy and Weinberg. 
D)  Darwin and Mendel. 
E)  Hershey and Chase.

Question 2

Explain how the CRP protein functions as a positive regulator of the lac operon.

Accepted Answer

A small nucleotide known as cAMP binds t

Question 3

A chaperone protein is used to aid in the transport of other proteins across cellular membranes.

Accepted Answer

A) True 
 B)False

Question 4

Which of the following statements about araC- and lacI- mutants are true,with reference their respective operons? Assume both of these are loss of function mutations.

Accepted Answer

A)  araC- mutants do not allow transcription,but lacI- mutants do 
B)  araC- mutants do allow transcription,but lacI- mutants do not 
C)  both araC- mutants and lacI- mutants allow transcription 
D)  neither araC- mutants nor lacI- mutants allow transcription 
E)  araC- mutants do allow transcription,but lacI- mutants do not,except if lacIs is also present 
A)  araC- mutants do not allow transcription,but lacI- mutants do 
B)  araC- mutants do allow transcription,but lacI- mutants do not 
C)  both araC- mutants and lacI- mutants allow transcription 
D)  neither araC- mutants nor lacI- mutants allow transcription 
E)  araC- mutants do allow transcription,but lacI- mutants do not,except if lacIs is also present

Question 5

How does the operator function in the regulation of an operon?

Accepted Answer

Binding of the repressor to th

Question 6

Which of the following choices is NOT a correct description of a reporter gene?

Accepted Answer

A)  a protein-encoding gene whose expression is easily quantifiable. 
B)  always co-translated as a fusion with another protein. 
C)  often fused to another gene's regulatory region to determine control. 
D)  may encode an enzyme. 
E)  a protein used to study gene expression. 
A)  a protein-encoding gene whose expression is easily quantifiable. 
B)  always co-translated as a fusion with another protein. 
C)  often fused to another gene's regulatory region to determine control. 
D)  may encode an enzyme. 
E)  a protein used to study gene expression.

Question 7

Medium #1 contains lactose.Medium #2 contains no lactose.Which of the following strains will produce a different level of β-galactosidase activity on medium #1 as on medium #2?

Accepted Answer

A)  lacIs,lacOc 
B)  lacIs,lacZ+ 
C)  lacI+,lacZ- 
D)  lacIs,lacZ- 
E)  lacI+,lacZ+ 
A)  lacIs,lacOc 
B)  lacIs,lacZ+ 
C)  lacI+,lacZ- 
D)  lacIs,lacZ- 
E)  lacI+,lacZ+

Question 8

A distinguishing feature of control of gene expression in prokaryotes is that transcription and translation occur completely independently of each other.

Accepted Answer

A) True 
 B)False

Question 9

The mechanisms of gene regulation discovered in E.coli are not found in most other prokaryotes.

Accepted Answer

A) True 
 B)False

Question 10

What is the role of the σ subunit of RNA polymerase in transcription?

Accepted Answer

The sigma subunit binds to RNA

Question 11

The presence of a diffusible gene product (e.g.protein)is a requirement for regulatory genes to act in trans.

Accepted Answer

A) True 
 B)False

Question 12

Describe the molecular subunit structure of the lac repressor and explain what enables it to bind to the operator.

Accepted Answer

The lac repressor protein is a tetramer

Question 13

Which of the following strains will be useful in demonstrating trans- regulation? In the genotypes listed below,the genes on the chromosome are on the left of the slash (/)symbol and the genes F' episome are on the right.

Accepted Answer

A)  lacI+ lacO+ lacZ+/lacI+ lacO+ lacZ+ 
B)  lacI+ lacOc lacZ+/lacI+ lacO+ lacZ- 
C)  lacI+ lacO+ lacZ+/lacI+ lacOc lacZ- 
D)  lacI+ lacO+ lacZ+/lacIs lacO+ lacZ- 
E)  lacIs lacOc lacZ+/lacI+ lacO+ lacZ- 
A)  lacI+ lacO+ lacZ+/lacI+ lacO+ lacZ+ 
B)  lacI+ lacOc lacZ+/lacI+ lacO+ lacZ- 
C)  lacI+ lacO+ lacZ+/lacI+ lacOc lacZ- 
D)  lacI+ lacO+ lacZ+/lacIs lacO+ lacZ- 
E)  lacIs lacOc lacZ+/lacI+ lacO+ lacZ-

Question 14

Which of the following combinations will produce the highest expression of ?-galactosidase? Assume crp- is a complete deletion of CRP (cAMP receptor protein).

Accepted Answer

A)  lacOc,crp- on medium with glucose but no lactose 
B)  lacOc,crp- on medium with lactose but no glucose 
C)  lacOc,crp- on medium with both glucose and lactose 
D)  lacOc,crp+ on medium with both glucose and lactose 
E)  lacOc,crp+,on medium with no lactose and no glucose 
A)  lacOc,crp- on medium with glucose but no lactose 
B)  lacOc,crp- on medium with lactose but no glucose 
C)  lacOc,crp- on medium with both glucose and lactose 
D)  lacOc,crp+ on medium with both glucose and lactose 
E)  lacOc,crp+,on medium with no lactose and no glucose

Question 15

The transition from transcriptional initiation to elongation involves

Accepted Answer

A)  binding of sigma factor. 
B)  release of sigma factor. 
C)  release of RNA polymerase from DNA. 
D)  binding of RNA polymerase to DNA. 
E)  binding of rho factor. 
A)  binding of sigma factor. 
B)  release of sigma factor. 
C)  release of RNA polymerase from DNA. 
D)  binding of RNA polymerase to DNA. 
E)  binding of rho factor.

Question 16

Describe the conditions for maximum induction of the lactose operon.

Accepted Answer

Bacteria are grown on a medium containin

Question 17

Explain how the presence or absence of the amino acid tryptophan attenuates the transcription of the genes in the trp operon.

Accepted Answer

This example illustrates attenuation or

Question 18

A common amino acid motif found in many of the polypeptides that function as repressors is

Accepted Answer

A)  Leucine zipper motif. 
B)  Zinc finger motif. 
C)  Helix-turn-helix motif. 
D)  Helix-loop-helix motif. 
E)  Alpha-beta-alpha motif. 
A)  Leucine zipper motif. 
B)  Zinc finger motif. 
C)  Helix-turn-helix motif. 
D)  Helix-loop-helix motif. 
E)  Alpha-beta-alpha motif.

Question 19

Attenuation of gene expression is unique to prokaryotes,because it requires translation of a leader sequence at the same time transcription is taking place.

Accepted Answer

A) True 
 B)False

Question 20

DNase is most useful in characterization of which of the following?

Accepted Answer

A)  cis- regulatory sites 
B)  trans- regulators 
C)  dimeric proteins 
D)  operons 
E)  reporter genes 
A)  cis- regulatory sites 
B)  trans- regulators 
C)  dimeric proteins 
D)  operons 
E)  reporter genes

Exam 9: Genome Annotation

The scientists who proposed the operon theory are

Explain how the CRP protein functions as a positive regulator of the lac operon.

A chaperone protein is used to aid in the transport of other proteins across cellular membranes.

Which of the following statements about araC- and lacI- mutants are true,with reference their respective operons? Assume both of these are loss of function mutations.

How does the operator function in the regulation of an operon?

Which of the following choices is NOT a correct description of a reporter gene?

Medium #1 contains lactose.Medium #2 contains no lactose.Which of the following strains will produce a different level of β-galactosidase activity on medium #1 as on medium #2?

A distinguishing feature of control of gene expression in prokaryotes is that transcription and translation occur completely independently of each other.

The mechanisms of gene regulation discovered in E.coli are not found in most other prokaryotes.

What is the role of the σ subunit of RNA polymerase in transcription?

The presence of a diffusible gene product (e.g.protein)is a requirement for regulatory genes to act in trans.

Describe the molecular subunit structure of the lac repressor and explain what enables it to bind to the operator.

Which of the following strains will be useful in demonstrating trans- regulation? In the genotypes listed below,the genes on the chromosome are on the left of the slash (/)symbol and the genes F' episome are on the right.

Which of the following combinations will produce the highest expression of ?-galactosidase? Assume crp- is a complete deletion of CRP (cAMP receptor protein).

The transition from transcriptional initiation to elongation involves

Describe the conditions for maximum induction of the lactose operon.

Explain how the presence or absence of the amino acid tryptophan attenuates the transcription of the genes in the trp operon.

A common amino acid motif found in many of the polypeptides that function as repressors is

Attenuation of gene expression is unique to prokaryotes,because it requires translation of a leader sequence at the same time transcription is taking place.

DNase is most useful in characterization of which of the following?

Mendels Principles of Heredity

Extensions to Mendels Laws

The Chromosome Theory of Inheritance

Linkage, Recombination, and the Mapping of Genes on Chromosomes

Dna Structure, Replication, and Recombination

Anatomy and Function of a Gene: Dissection Through Mutation

Gene Expression: the Flow of Information From Dna to Rna to Protein

Digital Analysis of Genomes

Analyzing Genomic Variation

The Eukaryotic Chromosome

Chromosomal Rearrangements and Changes in Chromosome Number

Bacterial Genetics

Organellar Inheritance

Gene Regulation in Prokaryotes

Gene Regulation in Eukaryotes

Manipulating the Genomes of Eukaryotes

The Genetic Analysis of Development

The Genetics of Cancer

Variation and Selection in Populations

Genetics of Complex Traits

Exploring Synthetic Biology: Concepts, Techniques, and Applications

Filters

Which of the following statements about araC^- and lacI^- mutants are true,with reference their respective operons? Assume both of these are loss of function mutations.

Which of the following combinations will produce the highest expression of ?-galactosidase? Assume crp^- is a complete deletion of CRP (cAMP receptor protein).