Chromosomes

Part of speech: noun

Definitions

1. Filamentous structures within cells that house genetic material, enabling heredity and cellular function
2. Thread-like bodies inside cells that contain DNA and guide the transmission of genetic traits
3. Cellular components made of DNA and protein that store and pass hereditary information to offspring

Etymology: "Chromosomes" is the plural of "chromosome," so its history is that of the singular. The word was coined in the 19th century in German, as "Chromosom," from Ancient Greek "khrôma" meaning "colour" and "sôma" meaning "body." The name reflects a practical fact of laboratory work: these threads only become visible when cells are treated with dyes, so they were named for how readily they took up colour. The Greek roots themselves had no link to biology. "Sôma" appears in ordinary Greek for a living body or corpse, and "khrôma" for the surface colour of something. Put together, the compound describes a "colored body," a label that tells you nothing about heredity, which was not yet understood when the name was made.

Synonyms: DNA strands, genetic material