Following statements describe the characteristics of the enzyme Restriction Endonuclease. Identify the incorrect statement.
Answer: (B) The enzyme binds DNA at specific sites and cuts only one of the two strands.. Answer: (B) The enzyme binds DNA at specific sites and cuts only one of the two strands.
- A.The enzyme cuts DNA molecule at identified position within the DNA.
- B.The enzyme binds DNA at specific sites and cuts only one of the two strands.✓
- C.The enzyme cuts the sugar-phosphate backbone at specific sites on each strand.
- D.The enzyme recognizes a specific palindromic nucleotide sequence in the DNA.
Correct Answer
(B) The enzyme binds DNA at specific sites and cuts only one of the two strands.
Solution & Explanation
Answer: (B) The enzyme binds DNA at specific sites and cuts only one of the two strands. Solution: This statement is INCORRECT. A restriction endonuclease, after binding its recognition site, cuts each of the two strands of the double helix at specific points in their sugar-phosphate backbones — not just one strand. The other three statements are all correct: it cuts at identified positions within DNA, cuts the sugar-phosphate backbone of each strand, and recognises a specific palindromic nucleotide sequence. NCERT Reference: Ch 9, p.166, line(s) 9-12 — "it will bind to the DNA and cut each of the two strands of the double helix at specific points in their sugar -phosphate backbones"