Question

Given below are two statements:
Statement I: Restriction endonucleases recognise specific sequences to cut DNA known as palindromic nucleotide sequences.
Statement II: Restriction endonucleases cut the DNA strand a little away from the centre of the palindromic site.
In the light of the above statements, choose the most appropriate answer from the options given below: 

• A. Both statement I and Statement II are correct
• B. Both statement I and Statement II are incorrect
• C. Statement I is correct but statement II is incorrect
• D. Statement I is incorrect but statement II is correct

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Restriction enzymes cut DNA at specific recognition sequences called palindromes.
Detailed Explanation:
- Statement I: Correct. Each restriction endonuclease recognizes a specific palindromic nucleotide sequence in the DNA (e.g., GAATTC for EcoRI).
- Statement II: Correct. Most restriction enzymes cut the two strands of DNA at different points, slightly away from the center of the palindrome, but between the same two bases on opposite strands. This staggered cut creates "sticky ends" (overhanging single-stranded regions).
Step 2: Final Answer:
Both statements are correct.