Question

In Lac-Operon if mutation occurs in the middle gene of the ‘structural gene’ then?

• A. Permease will not be synthesized
• B. β-Galactosidase will not be synthesized
  
• C. Transacetylase will not be synthesized
• D. Lactose digestion will be rapid

Answer 1

The correct option is A Permease will not be synthesized

Lac operon is an operon which is involved in the regulation of lactose metabolism in several enteric bacteria including Escherichia coli.

Mutation in structural genes will stop transcription. Structural genes are namely, lacZ, lacY and lacA. LacZ gene encodes for β-galactosidase, lacY encodes for β-galactoside permease and lacA encodes for β-galactoside transacetylase.

Hence if mutation occurs in the middle gene of the structural genes then permease will not be synthesized.

So, the correct answer is "option A"