Answer:
Exons code segments of a stretch of eukaryotic pre-mrna.
Explanation:
In eukaryotic organisms the genes that encode proteins are divided into exons (pieces of DNA coding) and introns (pieces of DNA not coding). Exons are the nucleotide series in DNA and RNA that are conserved in the creation of mature RNA. The process by which DNA is used while a pattern to create the mRNA is called transcription. RNA splicing is the method by which pre-mRNA is made in mature mRNA, intron removal and assembly together with exons.