NEETZoologyBiotechnology - Principles and Processes
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Insertion of alien DNA at the Pvu I site of pBR322 produces recombinants that cannot grow on ampicillin-containing medium. Reason (R): The Pvu I recognition site is located within the ampicillin resistance ( amp^R ) gene of pBR322. In the light of the above statements, choose the most appropriate a
Options
- ABoth Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
- BBoth Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of Assertion (A).
- CAssertion (A) is true but Reason (R) is false.
- DAssertion (A) is false but Reason (R) is true.
Correct answer
A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
Step-by-step solution
Assertion (A) is true because inserting alien DNA at the Pvu I site causes insertional inactivation of the ampicillin resistance ( amp^R ) gene. As a result, the recombinant plasmid loses ampicillin resistance, and the transformants cannot grow on an ampicillin-containing medium. Reason (R) is also true and provides the correct explanation for Assertion (A). The Pvu I recognition site is specifically located within the amp^R gene of the cloning vector pBR322, which is why insertion at this site disrupts the gene an