Q. Which one of the following palindromic base sequences in DNA can be easily cut at about the middle by some particular restriction enzyme?
A) 5′ CACGTA 3′; 3′ CTCAGT 5′
B) 5′ CGTTCG 3′; 3′ ATGGTA 5′
C) 5′ GATATG 3′; 3′ CTACTA 5′
D) 5′ GAATTC 3′; 3′ CTTAAG 5′
Explanation
[Solution from source] 5′-GAATTC-3′ / 3′-CTTAAG-5′ reads the same 5′→3′ on both strands, which makes it a true palindrome. It is the EcoRI recognition site, which is cut between G and A. The other pairs are not even complementary strands, let alone palindromes. Answer (4).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.