NEET 2002 · Class 12

Molecular Basis of Inheritance

[DIAGRAM: Structure of the lac operon in Escherichia coli showing regulator gene, promoter, operator, and structural genes; the regulator gene produces mRNA and repressor protein, and the repressor binds to the operator to block transcription.] In E. coli, during lactose metabolism repressor binds to:

  1. (A)regulator gene
  2. (B)operator gene
  3. (C)structural gene
  4. (D)promoter gene

The NCERT line that answers it

Verbatim line

The repressor protein binds to the operator region of the operon and prevents RNA polymerase from transcribing the operon.

Chapter
Molecular Basis of Inheritance
Section
5.8.1 The Lac operon
Page
22
Words matched
19 of 19

The answer appears as a continuous sentence in NCERT. This is that sentence.

How this line gives the answer

0, emb=0.9307, combined=0.9584). Verified: high — The span explicitly states 'The repressor protein binds to the operator region of the operon', which directly and conclusively answers the MCQ by identifying the operator as the binding site for the repressor during lactose metabolism.

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