DNA. Deoxyribonucleic acid (DNA<span>) is a nucleic acid that contains the genetic instructions for the development and function of </span>living things<span>. All known cellular life and some viruses contain </span>DNA<span>. The main role of </span>DNA<span> in the cell is the long-term storage of information.</span>
The nucleotide triplet that encodes an amino acid is called a codon. Each group of three nucleotides encodes one amino acid. Since there are 64 combinations of 4 nucleotides taken three at a time and only 20 amino acids, the code is degenerate (more than one codon per amino acid, in most cases).