A Point Mutation in the Operator of the Lac Operon

question 43

Multiple Choice

A point mutation in the operator of the lac operon would most likely cause

• A) no transcription of the lactose metabolizing genes, even when lactose is absent.
• B) no transcription of the lactose metabolizing genes, even when lactose is present.
• C) no binding of the repressor protein to the operator, even when lactose is absent.
• D) binding of the repressor protein to the regulatory gene in both the presence and absence of lactose.
• E) no transcription of the regulatory gene, even in the presence of lactose.