Assertion (A): Regulation of lac operon by re | vedclass

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(A) The $lac$ operon is a classic example of an inducible operon that is regulated by both negative and positive control mechanisms.Negative regulatio

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Both $A$ and $R$ are true and $R$ is the correct explanation of $A.$

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(A) The $lac$ operon is a classic example of an inducible operon that is regulated by both negative and positive control mechanisms.Negative regulation occurs because a repressor protein,encoded by the $i$ gene,binds to the operator region $(O)$ of the operon.When the repressor is bound to the operator,it physically blocks the $	ext{RNA}$ polymerase from binding to the promoter or moving forward to transcribe the structural genes.Since the presence of the repressor protein inhibits transcription,this mechanism is termed 'negative regulation'.Therefore,both the assertion and the reason are true,and the reason correctly explains why the regulation is called negative.

Assertion $(A):$ Regulation of $lac$ operon by repressor is referred to as negative regulation.
Reason $(R):$ Repressor protein binds to the operator region and prevents $\text{RNA}$ polymerase from transcribing the operon.

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Assertion $(A):$ Regulation of $lac$ operon by repressor is referred to as negative regulation.Reason $(R):$ Repressor protein binds to the operator region and prevents $\text{RNA}$ polymerase from transcribing the operon.