Deck 16: Regulation of Transcription in Prokaryotes

Question 1

Which of the following is an example of negative regulation?

A)A gene is switched on in the presence of an activator.
B)A gene is de-repressed.
C)A gene is induced.
D)A gene is switched off by a repressor protein.

Answer 1

D

Question 2

Transcriptional elements that bind to a DNA molecule where the gene they regulate is located are .

A)trans-acting elements
B)cis-acting elements
C)positive regulators
D)negative regulators

Answer 2

B

Question 3

Gratuitous inducers .

A)are metabolized like the natural inducer
B)are not broken down
C)are nutrient sources
D)are competitive inhibitors

Answer 3

B

Question 4

All of the following are associated with two-component regulatory systems except .

A)gratuitous inducer
B)phosphorelay
C)DNA binding regulator
D)sensor kinase

Question 5

Which of the following is not an inducer of the lac operon?

A)allo-lactose
B)IPTG
C)glucose
D)lactose

Question 6

Autoregulation occurs when .

A)IPTG binds to LacI
B)allo-lactose binds to LacI
C)a repressor binds to its own gene to prevent transcription
D)CRP binds to cAMP and the the lac operon

Question 7

Some nucleotides are involved in transcriptional regulation.

Question 8

Alternative sigma factors exist for all of the following except .

A)heat shock
B)nitrogen control
C)flagellar motion
D)exponential phase

Question 9

All of the following are examples of transcriptional regulation in prokaryotes except .

A)binding of a repressor to an operator
B)premature termination of RNA polymerase during transcription elongation
C)binding of cAMP-CRP complex to the lac operon of Escherichia coli
D)over-riding termination by anti-terminator proteins

Question 10

Global regulators .

A)control large numbers of genes in response to a broad,general signals
B)control large numbers of genes in response to a specific signal
C)control small numbers of genes in response to broad,general signals
D)control small numbers of genes in response to a specific signal