Question

Given below is a sample of a portion of the DNA strand giving the base sequences on the opposite strands. What is so special shown in it?
5’----GAATTC---3’
3’----CTTAAG---5’
(a)The palindromic sequence of base pairs
(b)Replication completed
(c)Deletion mutation
(d)Start codon at 5’ end

Answer 1

Hint: when going from 5’ to 3’ in the first strand, the sequence of bases that are present is the same as in the second strand in the same direction i.e. from 5’ to 3’.

Complete answer:
In the above-given sample, its complementary strand is the same while reading from the opposite direction, therefore it is a palindromic sequence. Palindromic sequences(palindrome-a word or phrase that read same from both sides) are those sequences in double-stranded DNA/RNA when its complementary strands read the same in the opposite direction i.e the strand going from 5' to 3' and its complementary strand from 3' to 5' must be complementary. For example, a typical nucleotide palindromic sequence would be TATA (5' to 3') and its complementary sequence from 3' to 5' would be ATAT.
So, the correct answer is, ‘Palindromic sequence of base pairs’.

Note:
-In a nucleic acid sequence, an exact palindrome is essentially even in length. This is because the middle base in a palindrome of odd length cannot be the same as its complement.
-In RNA it is Uracil as a nucleotide base instead of Thymine.