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:
Answer: (A) Both Statement I and Statement II are correct. Answer: (a) Both Statement I and Statement II are correct Solution: Statement I is correct — each restriction endonuclease recognises a specific palindromic nucleotide sequence in the DNA.
- 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
Correct Answer
(A) Both Statement I and Statement II are correct
Solution & Explanation
Answer: (a) Both Statement I and Statement II are correct Solution: Statement I is correct — each restriction endonuclease recognises a specific palindromic nucleotide sequence in the DNA. Statement II is also correct — restriction enzymes cut the DNA strand a little away from the centre of the palindrome site (between the same two bases on opposite strands), which generates the overhanging sticky ends. NCERT Reference: Ch 9, p.167, line(s) 8-9 — "Restriction enzymes cut the strand of DNA a little away from the centre of the palindrome sites, but between the same two bases on the opposite"