Dna

Part of speech: noun

Definitions

1. Deoxyribonucleic acid, the molecular structure that carries genetic information essential for the development and functioning of living organisms
2. A long polymer made from repeating units called nucleotides, which encode the instructions for life and heredity
3. The hereditary material in most organisms, consisting of two strands that coil around each other to form a double helix, storing the genetic blueprint for traits

Etymology: DNA is an initialism, a string of initial letters pronounced one at a time, standing for deoxyribonucleic acid. The name is built from chemical terms: "deoxy" marks the sugar in its backbone as one that has lost an oxygen atom compared with ribose, "ribo" refers to that sugar, "nucleic" to the nucleus where the molecule was first isolated, and "acid" to its acidic character. The full chemical name is therefore a description of the molecule's structure, packed into a single word. Because the initialism is so familiar, its letters have become a verb. To "DNA-test" someone, or to "DNA" a sample, means to analyse genetic material for identification or relationship, and this use is a later extension of the noun. Speakers now often treat the abbreviation as a plain word that needs no explanation, even though it began as a compressed list of chemical terms.