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NEETZoologyMolecular Basis of Inheritance

Which of the following statements accurately describes the i gene in the lac operon?

Options

  1. AIt requires the presence of lactose for its transcription.
  2. BGene i is constitutively expressed.
  3. CIt codes for the enzyme beta-galactosidase.
  4. DIt shares a common promoter with the structural genes z, y, and a.

Correct answer

B. Gene i is constitutively expressed.

Step-by-step solution

The i gene of the lac operon codes for the repressor protein and has its own promoter, separate from the structural genes (z, y, a). It is expressed constitutively , i.e. continuously and independent of lactose. It does not code for beta-galactosidase (that is the z gene). Hence the correct statement is that gene i is constitutively expressed.

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