Question 1

Which one of the following statements about eukaryotic versus prokaryotic gene regulation is not correct?

Accepted Answer

A)  Access to eukaryotic promoters is restricted by the structure of chromatin.
B)  Most regulation is positive,involving activators rather than repressors.
C)  Larger and more multimeric proteins are involved in regulation of eukaryotic transcription.
D)  Transcription and translation are separated in both space and time.
E)  Strong promoters in eukaryotes are generally fully active in the absence of regulatory proteins.

Question 2

Explain how synthesis of ribosomal proteins in E.coli is regulated at the level of translation.

Accepted Answer

Ribosomal proteins are encoded in severa...

Question 3

Which one of the following does not contribute to the activation of transcription in eurkaryotes?

Accepted Answer

A)  SWI/SNF chromatin remodeling proteins
B)  Histone acetyltransferases
C)  Histone methylases
D)  Histone deacetylases
E)  Alterations in histone content

Question 4

RecA protein provides the functional link between DNA damage and the SOS response by displacing the LexA protein from its operator sites on the SOS genes.RecA does so by:

Accepted Answer

A)  associating with polymerase holoenzyme to help it remove LexA from operator.
B)  bending LexA operator DNA to force dissociation of LexA repressor.
C)  binding to LexA protein to weaken directly its affinity for operator sites.
D)  causing self-cleavage of LexA,thus inactivating its binding to operator.
E)  competitively binding to LexA operators and serving as an activator.

Question 5

A regulon is a(n) :

Accepted Answer

A)  group of related triplet codons.
B)  network of operons with a common regulator.
C)  operon that is subject to regulation.
D)  protein that regulates gene expression.
E)  ribosomal protein that regulates translation.

Question 6

Transcription of the lactose operon in E.coli is stimulated by:

Accepted Answer

A)  a mutation in the repressor gene that strengthens the affinity of the repressor for the operator.
B)  a mutation in the repressor gene that weakens the affinity of the repressor for the operator.
C)  a mutation in the repressor gene that weakens the affinity of the repressor for the inducer.
D)  binding of the repressor to the operator.
E)  the presence of glucose in the growth medium.

Question 7

Large numbers of micro-RNAs (miRNAs),also known as small temporal RNAs (stRNAs),have now been discovered in higher eukaryotes.Describe their characteristics and general function.

Accepted Answer

Their primary transcripts are about 70 n...

Question 8

Which one of the following does not interact with mediator?

Accepted Answer

A)  TATA box
B)  TATA binding protein
C)  CTD of RNA polymerase
D)  TFIIH
E)  Modification and remodeling enzymes

Question 9

The DNA binding motif for many prokaryotic regulatory proteins,such as the lac repressor,is:

Accepted Answer

A)  helix-turn-helix.
B)  homeobox.
C)  homeodomain.
D)  leucine zipper.
E)  zinc finger.

Question 10

Which of the following base pairs can form a hydrophobic interaction with a protein in the major groove?

Accepted Answer

A)  A - T
B)  G - C
C)  T - A
D)  C - G
E)  Both A and C above

Question 11

Gene silencing by RNA interference acts by of the target gene.

Accepted Answer

A)  inhibiting transcription
B)  inhibiting translation
C)  inhibiting splicing
D)  degradation of the mRNA
E)  inhibiting polyadenylyation

Question 12

Briefly explain 
(a)why there is a lag in cell growth when bacteria are switched from a medium containing glucose to one containing lactose.
(b)When the growth medium contains both lactose and glucose,what proteins will be bound to the lac operon regulatory region? 
(c)If only lactose is in the growth medium,what proteins will be bound to the lac operon regulatory region?

Accepted Answer

(a)The lag represents the time required ...

Question 13

Protein structural motifs often have general functions in common.Which one of the following motifs is known to be involved in protein dimer formation but not in direct protein-DNA interactions?

Accepted Answer

A)  ( β\betaβ -barrel) 
B)  Helix-turn-helix
C)  Homeodomain
D)  Leucine zipper
E)  Zinc finger

Question 14

Describe briefly the process by which steroid hormones affect gene expression.

Accepted Answer

Steroid hormones usually enter a cell by...

Question 15

Usually,a mutation in the promoter region of an operon causes reduced levels of synthesis of the proteins encoded by that operon.Occasionally,a mutation in the promoter region actually causes increased levels of synthesis.Can you suggest a plausible explanation?

Accepted Answer

It is possible for a mutation to result ...

Question 16

Describe and contrast positive regulation and negative regulation of gene expression.

Accepted Answer

Positive regulation involves an activato...

Question 17

DNA-binding transactivating proteins often possess a domain separate from their DNA-binding domains that serves as a docking site for interactions with the transcription complex,coactivators,corepressors,or even chromatin remodeling proteins,to regulate gene transcription.Describe three known kinds of such domains,and provide an example of each.

Accepted Answer

(1)Gal4p (in yeast)has an acidic activat...

Exam 28: Regulation of Gene Expression

Correct Answer
verified
(1)Gal4p (in yeast)has an acidic activat...
View Answer

Which one of the following does not interact with mediator?

Correct Answer
verified

Gene silencing by RNA interference acts by of the target gene.

Correct Answer
verified

Which one of the following statements about eukaryotic versus prokaryotic gene regulation is not correct?

Correct Answer
verified

Which of the following base pairs can form a hydrophobic interaction with a protein in the major groove?

Correct Answer
verified

Describe briefly the process by which steroid hormones affect gene expression.

Correct Answer
verified
Steroid hormones usually enter a cell by...
View Answer

Correct Answer
verified
(a)The lag represents the time required ...
View Answer

Describe and contrast positive regulation and negative regulation of gene expression.

Correct Answer
verified
Positive regulation involves an activato...
View Answer

Transcription of the lactose operon in E.coli is stimulated by:

Correct Answer
verified

RecA protein provides the functional link between DNA damage and the SOS response by displacing the LexA protein from its operator sites on the SOS genes.RecA does so by:

Correct Answer
verified

Explain how synthesis of ribosomal proteins in E.coli is regulated at the level of translation.

Correct Answer
verified
Ribosomal proteins are encoded in severa...
View Answer

Protein structural motifs often have general functions in common.Which one of the following motifs is known to be involved in protein dimer formation but not in direct protein-DNA interactions?

Correct Answer
verified

The DNA binding motif for many prokaryotic regulatory proteins,such as the lac repressor,is:

Correct Answer
verified

Large numbers of micro-RNAs (miRNAs),also known as small temporal RNAs (stRNAs),have now been discovered in higher eukaryotes.Describe their characteristics and general function.

Correct Answer
verified
Their primary transcripts are about 70 n...
View Answer

Which one of the following does not contribute to the activation of transcription in eurkaryotes?

Correct Answer
verified

Usually,a mutation in the promoter region of an operon causes reduced levels of synthesis of the proteins encoded by that operon.Occasionally,a mutation in the promoter region actually causes increased levels of synthesis.Can you suggest a plausible explanation?

Correct Answer
verified
It is possible for a mutation to result ...
View Answer

A regulon is a(n) :

Correct Answer
verified

Exam 28: Regulation of Gene Expression

Correct Answerverified(1)Gal4p (in yeast)has an acidic activat...View AnswerShow Answer

Which one of the following does not interact with mediator?

Correct AnswerverifiedShow Answer

Gene silencing by RNA interference acts by of the target gene.

Correct AnswerverifiedShow Answer

Which one of the following statements about eukaryotic versus prokaryotic gene regulation is not correct?

Correct AnswerverifiedShow Answer

Which of the following base pairs can form a hydrophobic interaction with a protein in the major groove?

Correct AnswerverifiedShow Answer

Describe briefly the process by which steroid hormones affect gene expression.

Correct AnswerverifiedSteroid hormones usually enter a cell by...View AnswerShow Answer

Correct Answerverified(a)The lag represents the time required ...View AnswerShow Answer

Describe and contrast positive regulation and negative regulation of gene expression.

Correct AnswerverifiedPositive regulation involves an activato...View AnswerShow Answer

Transcription of the lactose operon in E.coli is stimulated by:

Correct AnswerverifiedShow Answer

RecA protein provides the functional link between DNA damage and the SOS response by displacing the LexA protein from its operator sites on the SOS genes.RecA does so by:

Correct AnswerverifiedShow Answer

Explain how synthesis of ribosomal proteins in E.coli is regulated at the level of translation.

Correct AnswerverifiedRibosomal proteins are encoded in severa...View AnswerShow Answer

Protein structural motifs often have general functions in common.Which one of the following motifs is known to be involved in protein dimer formation but not in direct protein-DNA interactions?

Correct AnswerverifiedShow Answer

The DNA binding motif for many prokaryotic regulatory proteins,such as the lac repressor,is:

Correct AnswerverifiedShow Answer

Large numbers of micro-RNAs (miRNAs),also known as small temporal RNAs (stRNAs),have now been discovered in higher eukaryotes.Describe their characteristics and general function.

Correct AnswerverifiedTheir primary transcripts are about 70 n...View AnswerShow Answer

Which one of the following does not contribute to the activation of transcription in eurkaryotes?

Correct AnswerverifiedShow Answer

Usually,a mutation in the promoter region of an operon causes reduced levels of synthesis of the proteins encoded by that operon.Occasionally,a mutation in the promoter region actually causes increased levels of synthesis.Can you suggest a plausible explanation?

Correct AnswerverifiedIt is possible for a mutation to result ...View AnswerShow Answer

A regulon is a(n) :

Correct AnswerverifiedShow Answer

Correct Answer
verified
(1)Gal4p (in yeast)has an acidic activat...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Steroid hormones usually enter a cell by...
View Answer

Correct Answer
verified
(a)The lag represents the time required ...
View Answer

Correct Answer
verified
Positive regulation involves an activato...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Ribosomal proteins are encoded in severa...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Their primary transcripts are about 70 n...
View Answer

Correct Answer
verified

Correct Answer
verified
It is possible for a mutation to result ...
View Answer

Correct Answer
verified