The abbreviation stands for deoxyribonucleic acid, a double-stranded nucleic acid, in which the two strands twist together to form a helix. The strands consist of sugar and phosphate groups, the sugars being attached to a base — adenine, thymine, guanine, or cytosine. In DNA the bases pair to form a ladder-like structure, with adenine paired with thymine and guanine with cytosine. DNA forms the basis of inheritance in all organisms, except viruses, the DNA code being sufficient to build and control the organism. DNA is located in the nucleus of all cells; it is the substance of the chromosomes that separate out from the nucleus when cells divide, and it carries the genes, each of which is a segment of a DNA molecule. A small fraction of total DNA is present in mitochondria that codes for a few mitochondrial proteins. This DNA is passed down the female line from the mitochondria contained in the ovum.
— Alan W. Cuthbert
Bibliography
- Watson, J. D. (1968). The double helix. Weidenfeld and Nicolson,
See cell; genetics, human.
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