gene

Etymology

From German Gen, from Ancient Greek γενεά (geneá, “generation, descent”), from the aorist infinitive of γίγνομαι (gígnomai, “I come into being”). Coined by the Danish biologist Wilhelm Ludvig Johannsen in a German-language publication, from the last syllable of pangene.

noun

1. (genetics) A theoretical unit of heredity of living organisms; a gene may take several values and in principle predetermines a precise trait of an organism's form (phenotype), such as hair color.
   Coordinate term: cistron
   The US supreme court has ruled unanimously that natural human genes cannot be patented, a decision that scientists and civil rights campaigners said removed a major barrier to patient care and medical innovation. 2013-06-21, Karen McVeigh, “US rules human genes can't be patented”, in The Guardian Weekly, volume 189, number 2, page 10
2. (molecular biology) A segment of DNA or RNA from a cell's or an organism's genome, that may take several forms and thus parameterizes a phenomenon, in general the structure of a protein; locus.
   A change in a gene is reflected in the protein or RNA molecule that it codes for.
   A length of DNA is divided into segments called chromosomes and shorter individual units called genes. 2019, Bill Bryson, The Body: A Guide for Occupants, Black Swan (2020), page 7