Before revision: The atoms in the structure are colour-coded by element and the detailed structures of two base pairs are shown in the bottom right.Simplified diagram Deoxyribonucleic acid (; DNA) is a polymer composed of two strands that coil around each other to form a double helix.
After revision: The atoms in the structure are colour-coded by element and the detailed structures of two base pairs are shown in the bottom right.Simplified diagram Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix.