DNA looks like a twisted ladder or spiral staircase, scientifically known as a double helix. It consists of two long strands coiled around each other, with a backbone made of alternating sugar (deoxyribose) and phosphate groups. The rungs of the ladder are pairs of nitrogenous bases: adenine pairs with thymine, and cytosine pairs with guanine. This structure resembles two corkscrew shapes connected in the middle, like a twisty zipper, and the strands are antiparallel, meaning they run in opposite directions along the helix.
