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MHT CET Medical202626 April 2026Morning ShiftBiologyMolecular Basis of InheritanceActual

In lac operon, which of the following acts as inducer and bind to repressor?

Options

  1. AGlucose
  2. BLactose
  3. CGalactose
  4. DSucrose

Correct answer

B. Lactose

Step-by-step solution

In the lac operon, lactose (specifically its isomer allolactose) acts as an inducer. The inducer binds to the repressor protein, causing a conformational change that prevents the repressor from binding to the operator region. This allows RNA polymerase to access the promoter and transcribe the structural genes. Answer: Lactose

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