Question

question 2
a palindromic dna sequence reads the same in both directions on complementary strands.
which of the following is not a palindromic sequence?
a 5-gaattc-3
b 5-cgatcg-3
c 5-gcgc-3
d 5-aagcta-3

Explanation:

A palindromic DNA sequence has the property that the sequence on one strand is the reverse complement of the sequence on the complementary strand.

• For option A: The complementary strand of \(5'\)-GAATTC-\(3'\) is \(3'\)-CTTAAG-\(5'\). When reversed, it is \(5'\)-GAATTC-\(3'\), so it is palindromic.
• For option B: The complementary strand of \(5'\)-CGATCG-\(3'\) is \(3'\)-GCTAGC-\(5'\). When reversed, it is \(5'\)-CGATCG-\(3'\), so it is palindromic.
• For option C: The complementary strand of \(5'\)-GCGC-\(3'\) is \(3'\)-CGCG-\(5'\). When reversed, it is \(5'\)-GCGC-\(3'\), so it is palindromic.
• For option D: The complementary strand of \(5'\)-AAGCTA-\(3'\) is \(3'\)-TTCGAT-\(5'\). When reversed, it is \(5'\)-TACGTT-\(3'\), which is not the same as the original sequence \(5'\)-AAGCTA-\(3'\), so it is not palindromic.

Answer:

D. \(5'\)-AAGCTA-\(3'\)