Suppose a gene has three exons, with 570 nucleotides in exon 1, 420 in exon 2, and 810 in exon 3. during a splicing event, exon 2 is accidently spliced out. what is the length of mature mrna from this gene?

The answer is 570 + 810 = 1380 nucleotides. During transcription, a primary transcript is first created. It is later processed into a pre-mRNA than contains introns (regions that do not code for proteins). The introns are subsequently spliced out to form the mature mRNA.