NEET 2016 · Class 12

Molecular Basis of Inheritance

Which of the following is required as inducer(s) for the expression of Lac operon?

  1. (A)lactose and galactose
  2. (B)glucose
  3. (C)galactose
  4. (D)lactose

The NCERT line that answers it

Verbatim line

Lactose is the substrate for the enzyme beta-galactosidase and it regulates switching on and off of the operon.

Chapter
Molecular Basis of Inheritance
Section
5.8.1 The Lac operon
Page
22
Words matched
49 of 49

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

How this line gives the answer

0, emb=1.0, combined=1.0). Verified: high — The span explicitly states 'Lactose is the substrate for the enzyme beta-galactosidase and it regulates switching on and off of the operon. Hence, it is termed as inducer,' which directly identifies lactose as the inducer required for Lac operon expression, matching option D.

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