Control of Gene Expression MCQs
Questions with 100% Answers Correct
What would happen to the regulation of the tryptophan operon in cells that express a
mutant form of the tryptophan repressor that cannot bind to DNA?
1.Trp operon will be permanently ON
2.Trp operon will be permanently OFF - ANSWERS1.Trp operon will be permanently
ON
what would happen to the regulation of the tryptophan operon in cells that express a
mutant form of the tryptophan repressor that cannot bind tryptophan?
1.Trp operon will be permanently ON
2.Trp operon will be permanently OFF - ANSWERS1.Trp operon will be permanently
ON
What would happen to the regulation of the tryptophan operon in cells that express a
mutant form of the tryptophan repressor that binds to DNA even in the absence of
tryptophan?
1.Trp operon will be permanently ON
2.Trp operon will be permanently OFF - ANSWERS2.Trp operon will be permanently
OFF
What happens to the lac operon if both glucose and lactose are present?
1. Lac operon is ON because Lac repressor is not expressed
2. Lac operon is ON because CAP bound to the promoter
3. Lac operon is OFF because CAP not bound to the promoter
4. Lac operon is OFF because Lac repressor is bound to the operator - ANSWERS3.
Lac operon is OFF because CAP not bound to the promoter
what happens to the lac operon if glucose is present but lactose is not present?
1. Lac operon is ON because Lac repressor is not expressed
2. Lac operon is ON because Lac repressor not bound to the operator
