A segment of a DNA or RNA molecule containing information coding for a protein or peptide sequence.Compare with intron
- ‘All of them contained usually short fragments of coding sequences corresponding to exons of single-copy genes.’
- ‘The structure of the invertase genes are fairly similar, each containing between six and eight exons.’
- ‘As a result, the protein sequences encoded by these exons are nearly identical between the two species.’
- ‘He concluded that recombination had separated the genealogical histories of introns and exons within these genes.’
- ‘Sequence data for each gene encompassed all coding exons and the intervening introns.’
1970s: from expressed (see express) + -on.
Each of the four officers acting as commanders of the Yeomen of the Guard.
Mid 18th century: representing the pronunciation of French exempt ‘free from’, from Latin exempt- ‘taken out’, from the verb eximere, so named because these officers were exempt from normal duties.
We take a look at several popular, though confusing, punctuation marks.