試題詳解

21.The cell metabolism is tightly connected to the regulation of gene expression. The lac operon (lactose operon) is an example. Which statement below regarding the lac operon is correct?
(A)There are lacZ, lacY and lacA genes in lac operon and they are transcribed ind

(B)RNA polymerase binds to operator in the absence of lactose.

(C) The operon is controlled by negative and positive transcription factors.

(D) In the presence of lactose, the lac repressor encoded by the lacI gene is not expressed for ope

ron activation.
(E) In the presence of high concentration glucose, the catabolite activator.protein (CAP) is activated to increase Lac Zexpression.