Q.A low level of expression of lac operon occurs at all the windows for treatment of various genetic disorders. Justify the statement.
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Start your 14-day free trial to unlock the full solution →Step 1. Recall how the lac operon is normally regulated. In the absence of lactose, the lac repressor protein binds to the operator region and blocks RNA polymerase from efficiently transcribing the structural genes (lacZ, lacY, lacA). In the presence of lactose (via its isomer allolactose), the repressor's shape changes, it releases the operator, and transcription rises sharply.
Step 2. Explain why expression is never truly zero. The repressor-operator binding is not permanent or absolute — it is a dynamic equilibrium. Occasionally the repressor dissociates from the operator for brief moments even without an inducer, allowing RNA polymerase to transcribe the genes at a very low (basal/leaky) rate. This is what is meant by 'a low level of expression occurring at all times.' …
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