Which one of the following represents a palindromic sequence in DNA?

5' GAATTC 3'3' CTTAAG 5' represents a palindromic sequence because the sequence reads the same forwards and backwards. A palindromic sequence in DNA is a sequence that reads the same in the 5' to 3' direction on one strand as it does in the 5' to 3' direction on the complementary strand. In this case, the sequence GAATTC on the top strand is complementary to CTTAAG on the bottom strand. If you read 5' GAATTC 3' and then the complementary strand 5' CTTAAG 3', you will notice that the latter sequence is simply the reverse of the former.