An intron is a non-coding region of DNA. During alternative splicing, introns are removed.
During eukaryotic transcription, a fragment of DNA (e.g., a gene) is used as a template to synthesize a complementary RNA sequence, usually a precursor mRNA (pre-mRNA).
Subsequently, this pre-mRNA is processed by a mechanism called alternative splicing in order to produce a mature mRNA which is then used as template to synthesize a protein by a process called translation.
During alternative splicing, non-coding regions of a gene called 'introns' are removed, where coding regions called 'exons' are spliced back together.
If a cell transcribed and translated a gene’s intron by mistake, then additional amino acids would be inserted into the protein and therefore the resulting protein will be longer than normal.
