The lactose operon is under both positive and negative regulation. A bacterial cell does not want to waste the energy to synthesize enzymes to degrade an energy source if that energy source is not present therefore, the lactose operon is regulated to produce enzymes to break down lactose only if lactose is present. When lactose is absent we would expect ALL BUT ONE of these steps to occur.
A) The lac repressor is deactivated.
B) The repressor binds the operator.
C) The lac repressor protein is synthesized in its active form.
D) RNA polymerase is blocked from binding to the promoter sequence.