What is a clue that the lac operon is on? A.)Lactose is absent.

B.)The cell membrane changes.

C.)The repressor protein has fallen off the molecule.

D.)RNA polymerase is blocked by the repressor.

The repressor protein has fallen off the molecule.

regulation of gene expression. gene expression can be regulated by various cellular processes with the aim to control the amount and nature of the expressed genes. these regulatory proteins bind to dna and send signals that indirectly control the rate of gene expression

explanation:

if your own plato the answer is b. the fern transitioned from sporophyte generation to gametophyte generation.