Question

The figure given below shows lac operon and its function. Identify A, B, C and D respectively:

• A. A-Repressor, B-Inducer, C-Permease, D-B galactosidase
• B. A-Repressor, B-Inducer, C-B galactosidase, D-Transacetylase
• C. A-Inducer, B-Repressor, C-B galactosidase, D-Transacetylase
• D. A-Repressor, B-Inducer, C-Transacetylase, D-Permease

Hint:

Remember lac operon components: Repressor, Inducer, Permease, β-galactosidase.
A = Repressor, B = Inducer, C = Transport enzyme, D = Catabolic enzyme.
Visualize lac operon diagram to answer matching questions quickly.

Answer 1

The Correct Option is A

1. In lac operon, A = Repressor protein, which binds operator to prevent transcription.
2. B = Inducer (allolactose) inactivates repressor and allows transcription.
3. C = Permease, facilitates lactose entry into the cell.
4. D = β-galactosidase, hydrolyzes lactose to glucose and galactose.
5. Hence the correct assignment is (1) A-Repressor, B-Inducer, C-Permease, D-B galactosidase.