NURSING EXAM QUESTIONS
MICROBIOLOGY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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repressor is attached to the operator gene and does not allow trancription of the promoter region
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repressor is attached to the inducer
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repressor protein produces enzymes
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repressor forms a complex with the inducing subtrate
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Detailed explanation-1: -In absence of an inducer, the repressor protein binds to the operator region and prevents RNA polymerase from transcribing the structural gene. Thus, the lac operon gene is inactivated.
Detailed explanation-2: -The lac repressor is innately active, and in the absence of lactose it switches off the operon by binding to the operator.
Detailed explanation-3: -The lac repressor is a protein that represses (inhibits) transcription of the lac operon. It does this by binding to the operator, which partially overlaps with the promoter. When bound, the lac repressor gets in RNA polymerase’s way and keeps it from transcribing the operon.
Detailed explanation-4: -In the absence of the inducer (Lactose in Lac operon), the repressor protein binds to the operator and blocks the path of RNA polymerase and prevents the expression of structural genes.