Assertion: Restriction enzyme digestions are performed by incubating purified DNA molecules with the restriction enzyme, at the optimal conditions for that specific enzyme.

Reason: DNA is a negatively charged molecule, hence it moves towards the positive electrode (anode) during agarose gel electrophoresis.

Both Assertion (A) and Reason (R) are correct  but R is not the correct explanation of A.

The correct answer is Option (2) – Both Assertion (A) and Reason (R) are correct but R is not the correct explanation of A.

Explanation:

• Assertion (A) is correct: Restriction enzyme digestions are indeed performed by incubating purified DNA molecules with the restriction enzyme at the optimal conditions for that specific enzyme. This ensures that the enzyme functions effectively and cuts the DNA at the intended sites.
• Reason (R) is correct: DNA is a negatively charged molecule and moves towards the positive electrode (anode) during agarose gel electrophoresis. This property of DNA allows its movement through the gel when an electric field is applied.

However, the reason provided (DNA's movement towards the anode during electrophoresis) does not explain the assertion (the procedure of performing restriction enzyme digestions). Therefore, while both statements are true, the reason does not directly explain the assertion.