Biochemistry

Question: Enhancers differ from promoters in that
[A].

they initiate transcription

[B].

they are adjacent to the start codon

[C].

their orientation can be inverted without effect

[D].

they are restricted to a specific gene

Answer: Option C

Explanation:

No answer description available for this question.

Question: A frameshift mutation occurs in the sigma subunit gene transcribed as part of SPOl early genes. What will be the immediate result?
[A].

Early genes will not be translated

[B].

Middle genes will not be transcribed

[C].

The bacterial host will lyse immediately

[D].

Infection will proceed as usual

Answer: Option C

Explanation:

No answer description available for this question.

Question: In the presence of high levels of tryptophan
[A].

attenuator allows transcription of trp structural genes

[B].

attenuator propogates transcription

[C].

attenuator terminates transcription

[D].

none of the above

Answer: Option C

Explanation:

No answer description available for this question.

Question: A mutation in the tip binding site of the repressor would result in
[A].

constitutive trp operon expression

[B].

inducible trp operon expression

[C].

no operon expression

[D].

none of the above

Answer: Option A

Explanation:

No answer description available for this question.

Question: In the presence of tryptophan in the cell, the repressor is __________
[A].

bound to tryptophan

[B].

bound to DNA

[C].

bound to both DNA and tryptophan

[D].

bound to neither tryptophan nor DNA

Answer: Option C

Explanation:

No answer description available for this question.

Question: Which of the following occur in the presence of glucose?
[A].

lac Z gene expression is increased

[B].

cAMP increases

[C].

Binding of CAP-cAMP complex to the promoter area decreases

[D].

none of the above

Answer: Option C

Explanation:

No answer description available for this question.

Question: Catabolite activating protein exerts __________ control on transcription of the lac operon genes.
[A].

positive

[B].

negative

[C].

may be positive or negative

[D].

none of these

Answer: Option A

Explanation:

No answer description available for this question.

Question: Why are several structural genes regulated as a unit in bacteria?
[A].

An accident of evolution

[B].

It allows coordinating regulation of genes with a common function

[C].

The bacteria chromosome is so small; many different genes must be controlled by the same promoter

[D].

none of the above

Answer: Option B

Explanation:

No answer description available for this question.