Deoxyribonucleic acid. DNA is one of two types of molecules which encode genetic information, the other being RNA. DNA is the genetic material in humans and RNA is transcribed from it. DNA forms a double stranded molecule held together between the base pairs of nucleotides. This molecule forms a double helix. There are four nucleotides in DNA, each containing a base; adenine (A), guanine (G), cytosine (C) or thymine (T).
