Question

What is polarity with reference to double stranded DNA ?

Answer 1

The double-stranded has no polarity. This observation by Francis Crick, based on Rosalind Franklin's work, was one of the crucial steps in working out the structure of DNA. Since each strand has a 3′OH end and a 5′PO4 end, the only way the molecule has no polarity is if the two strands are antiparallel.