In the lac operon of E. coli, the 'i' gene codes for a repressor protein. In the absence of lactose, the repressor binds to the: MCQ with Answer and Explanation

In the lac operon, the 'i' gene (regulatory gene) constitutively produces a repressor protein. In the absence of lactose (the inducer), this active repressor binds specifically to the operator region of the operon. The operator overlaps with the promoter, physically blocking RNA polymerase from binding to the promoter or moving forward to transcribe the structural genes (z, y, a). When lactose is present, it binds to the repressor, inactivating it and allowing transcription.