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): When a vector and a source DNA are cut by the same restriction endonuclease, the resultant DNA fragments have the same kind of sticky ends. Reason (R): Restriction endonucleases produce sticky ends by cutting both DNA strands exactly at the centre of their palindromic recognition sequence. In the l
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
C. Assertion (A) is true but Reason (R) is false.
Step-by-step solution
Assertion (A) is true because cutting both the vector and the source DNA with the same restriction endonuclease ensures that the resulting fragments possess complementary overhangs, known as the same kind of sticky ends. This allows them to be joined easily by DNA ligase. Reason (R) is false. To produce sticky ends, restriction endonucleases cut the DNA strands a little away from the centre of the palindrome sites, but between the same two bases on the opposite strands. Cutting exactly at the centre of the palindro