NEETZoologyMolecular Basis of Inheritance
Match List-I with List-II regarding the lac operon in E. coli: List-I List-II A. Lactose I. Codes for the repressor protein B. Repressor protein II. Binding site for the repressor C. Operator III. Binds to the operator to prevent transcription D. i gene IV. Acts as an inducer to inactivate the repressor Choose the correct answer from the options given below:
Options
- AA-IV, B-III, C-II, D-I
- BA-IV, B-II, C-III, D-I
- CA-I, B-III, C-II, D-IV
- DA-IV, B-I, C-II, D-III
Correct answer
A. A-IV, B-III, C-II, D-I
Step-by-step solution
The i gene is a regulatory gene that constitutively codes for the repressor protein (D matches I). The repressor protein binds to the operator region of the operon to prevent transcription by RNA polymerase (B matches III). The operator is the specific DNA sequence adjacent to the promoter where the repressor binds (C matches II). Lactose acts as an inducer by binding to the repressor protein and inactivating it, thereby turning the operon on (A matches IV). Therefore, the correct matching sequence is A-IV, B-III,