DNA

The DNA - The abbreviation for deoxyribonucleic acid. DNA is the principal molecule carrying genetic information in almost all organisms; the exceptions are certain viruses that use RNA.

DNA is found in the chromosomes of cells; its double-helix structure allows the chromosomes to be copied exactly during the process of cell division.

A special form of DNA exists in mitochondria, the tiny energy-producing structures within cells (see mitochondrial DNA). Sections of DNA can also be created artificially (see recombinant DNA) during genetic engineering. (See also meiosis; mitosis; nucleic acids.)