Question

how the lac operan operates both in presence and absence of an inducer in E. coli​

Answer 1

⠀⠀ ⠀ ⠀⠀ $\huge{\tt{\red{❥}\green{A}\purple{N}\pink{S}\blue{W}\orange{E}\red{R}}}$The repressor protein binds to the operator region of the operon and prevents RNA polymerase from transcribing the operon. In the absence of inducer the the repressor is active and the RNA polymerase cannot access the promoter region and hence the transcription does not take place.