NEETZoologyMolecular Basis of Inheritance
Match List-I with List-II regarding the components of the lac operon. List-I List-II (A) i gene (I) Interacts with repressor protein to inactivate it (B) Operator (II) Binding site for RNA polymerase (C) Promoter (III) Synthesizes repressor constitutively (D) Inducer (IV) Binding site for the active repressor Choose the correct answer from the options given below:
Options
- A(A)-(III), (B)-(II), (C)-(IV), (D)-(I)
- B(A)-(I), (B)-(IV), (C)-(II), (D)-(III)
- C(A)-(III), (B)-(IV), (C)-(I), (D)-(II)
- D(A)-(III), (B)-(IV), (C)-(II), (D)-(I)
Correct answer
D. (A)-(III), (B)-(IV), (C)-(II), (D)-(I)
Step-by-step solution
The i gene is a regulatory gene that is expressed constitutively to synthesize the repressor protein. Therefore, (A) matches with (III). The operator region is the specific DNA sequence where the active repressor protein binds to prevent transcription. Therefore, (B) matches with (IV). The promoter is the sequence where RNA polymerase binds to initiate transcription of the structural genes. Therefore, (C) matches with (II). The inducer (lactose or allolactose) binds to the repressor protein, inactivating it so that