Complex sentence: In many genes, each exon contains part of the open reading frame (ORF) that codes for a specific portion of the complete protein, however, the term exon is often misused to refer only to coding sequences for the final protein.
Split into simpler sentences: In many genes, each exon contains part of the open reading frame (ORF) that codes for a specific portion of the complete protein. However, the term "exon" is often misused to refer only to coding sequences for the final protein.