Genetic information. Conceptual computer artwork of a human head, a DNA molecule and genetic code. The strands winding from top to bottom represent the double helix of the deoxyribonucleic acid (DNA) molecule. The letters (A,T,G,C) represent the four nucleotide bases of DNA: adenine, thymine, guanine and cytosine. DNA is split into sections, called genes, which encode the body's genetic information. Genes determine each cell's structure, function and behaviour. This image could represent human cloning or the use of genetics in medicine and insurance.