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NEET2022Zoology-Restriction Enzymes

NEET 2022 Zoology Restriction Enzymes Assertion Reason Question

Type: Assertion Reason-conceptual-Medium-Class 12

Given below are two statements:

Statement I: Restriction endonucleases recognise specific sequence to cut DNA known as palindromic nucleotide sequence.

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

Statement I is correct but Statement II is incorrect

B

Statement I is incorrect but Statement II is correct

C

Both Statement I and Statement II are correct

D

Both Statement I and Statement II are incorrect

Correct Answer

Option C

Detailed Explanation

Chapter: Biotechnology: Principles & Processes

Class: 12 | Topic: Restriction Enzymes | Difficulty: 🟡 Medium

✅ Ans: C — Both Statement I and Statement II are correct

  • Statement I ✅: Restriction enzymes recognise specific palindromic DNA sequences.
  • Statement II ✅: They cut the two DNA strands slightly away from the centre of the palindrome, producing sticky ends.

📌 NCERT: Restriction enzymes cut DNA at specific recognition sites, often producing sticky ends.

🧠 Quick Revision: Restriction enzyme → Palindromic sequence → Staggered cut → Sticky ends

Example:

5′−GAATTC−3′5' - GAATTC - 3' 3′−CTTAAG−5′3' - CTTAAG - 5'

Both statements → Correct → C

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