Question

if a strain of bacteria had a mutation that blocked expression of the lac repressor, what would you expect as a result? multiple choice the mutant strain would grow at the same rate as wildtype if lactose was not present. the mutant strain would act the same, because it would still require lac activator protein to turn on. the mutant strain would outcompete wildype strains, since it could always utilize lactose. the mutant strain would waste energy producing enzymes in the absence of lactose.

Explanation:

The lac - repressor normally inhibits the expression of genes involved in lactose metabolism when lactose is absent. Without the lac - repressor due to mutation, the genes for lactose metabolism will be expressed even in the absence of lactose. This leads to the wasteful production of enzymes that are not needed when lactose is not present.

Answer:

The mutant strain would waste energy producing enzymes in the absence of lactose.