Noun
(genetics) a segment of DNA that is involved in producing a polypeptide chain; it can include regions preceding and following the coding DNA as well as introns between the exons; it is considered a unit of heredity
Source: WordNetgenes were formerly called factors Source: Internet
The cistron DNA is transcribed into the first of a series of RNA intermediates. Source: Internet
The words cistron and gene were coined before the advancing state of biology made it clear that the concepts they refer to are practically equivalent. Source: Internet