2. Questions Bank
  3. 12th Class
  4. Biology
  5. Molecular basis of Inheritance / विरासत का आणविक आधार

12th Class Biology Molecular basis of Inheritance / विरासत का आणविक आधार Question Bank MCQs - Molecular Basis of Inheritance

  • question_answer
    In E. coli the lac operon gets switched on when    

    A) lactose is present and it binds to the represser

    B) represser binds to operator

    C) RNA polymerase binds to the operator

    D) lactose is present and it binds to RNA polymerase

    Correct Answer: A

    Solution :

    [a] When lactose is present, it act as an inducer and binds to the represser and inactivates it. This represser fails to bind to operator. Therefore, the RNA polymerase binds to the promoter and transcript lac mRNA, thus switching on the lac operon and allowing transcription to proceed.


You need to login to perform this action.
You will be redirected in 3 sec spinner