Brief description about how the SHAPE of DNA:
DNA is a double helical structure. The structure of DNA was described by Watson and Creek. They were scientists who got the structure of the DNA by Xray crystallography. They said that the DNA is a double helical structure that is composed of two sugar phosphate backbones that are having one nitrogen base on each sugar molecule.
Each sugar phosphate backbone is at an angle of 36° with the preceding or the succeeding one. They are placed at 20A apart. Each nitrogen base is either Adenine, thymine, guanine or cytosine. Adenine is complementary to thymine and guanine to cytosine. They are complementarily present on the two corresponding sugar phosphates chains. They are 34A to complete one full cycle of the helix.