Question

Given below is a sample of a portion of DNA strand giving the base sequence on the opposite strands. What is so special shown in it?

5'-------GAATTC------3'
3'-------CTTAAG------5'

• A. Palindromic sequence of base pairs
• B. Replication completed
• C. Deletion mutation
• D. Start codon at the 5' end

Answer 1

Answer: (A)

Palindromic sequence of base pairs

If a nucleic acid sequence (DNA or RNA) is read same from 5' to 3' on one strand and 5' to 3' on its complementary strand, the sequence is called as palindromic sequence. In the question, the base sequence is same whether read from 5' to 3' upper strand (5' GAATTC 3') or 5' to 3' (5' GAATTC 3') on the lower strand. Correct answer is A.