Answer: DNA stores biological information in sequences of four bases of nucleic acid — adenine (A), thymine (T), cytosine (C) and guanine (G) — which are strung along ribbons of sugar- phosphate molecules in the shape of a double helix.
Explanation:
DNA is made of chemical building blocks called nucleotides. These building blocks are made of three parts: a phosphate group, a sugar group and one of four types of nitrogen bases. To form a strand of DNA, nucleotides are linked into chains, with the phosphate and sugar groups alternating