Observe the given picture and answer the following questions ?
What occurs in the presence of an inducer such as lactose or allolactose?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) -The repressor is inactivated
The repressor of the operon is synthesised (all-the-time – constitutively) from the i gene. The repressor protein binds to the operator region of the operon and prevents RNA polymerase from transcribing the operon. In the presence of an inducer, such as lactose or allolactose, the repressor is inactivated by interaction with the inducer. This allows RNA polymerase access to the promoter and transcription proceeds . Essentially, regulation of lac operon can also be visualised as regulation of enzyme synthesis by its substrate.