DNA (Deoxyribonucleic acid) is the hereditary material of all living organisms, including humans.

Double stranded helix with two sides connected together by multiple combinations of 4 different bases. The 4 bases are shown in 4 different colors.

Figure 1: DNA double helix

DNA is a double helix made of two complementary strands. The information stored in DNA consists of instructions for building and maintaining all the cells of an organism.

The human genome consists of approximately 3.2 billion base pairs. Because of the enormous size of DNA, eukaryotes have developed an efficient DNA packaging system.

DNA is found in the nucleus, chloroplasts, and mitochondria of eukaryotes. In prokaryotes, the DNA is not enclosed in a membranous envelope.