What effect would you expect if gene expression of the lac operon were completely repressed ?

Question

What effect would you expect if gene expression of the lac operon were completely repressed ? (A) The cell would be more efficient without 'wasting' the energy required for the low level of Lac Z, LacY, and Lac A gene expression. (B) Allolactose would accumulate within the cell and become toxic. (C) Lactose would not be converted into the inducer and the operon could not be induced. (D) All of the above

Tardigrade Admin · Accepted Answer

A low level of Lac Z expression is required for conversion of lactose to the inducer, allolactose.

Q. What effect would you expect if gene expression of the lac operon were completely repressed ?

The cell would be more efficient without 'wasting' the energy required for the low level of Lac Z, LacY, and Lac A gene expression.

Allolactose would accumulate within the cell and become toxic.

Lactose would not be converted into the inducer and the operon could not be induced.

All of the above

A low level of Lac Z expression is required for conversion of lactose to the inducer, allolactose.