The Alternative Splicing of a Certain Transcript Can Result in the Production

The alternative splicing of a certain transcript can result in the production of two mRNA isoforms, one predominant in muscle cells and the other in neurons. The gene contains an exon that is skipped in muscle cells but retained in neurons. You create a mutant version of the gene in which the 3? splice site near this exon is deleted. However, when you introduce this into a culture of neural cells, an even longer pre-mRNA is produced, consistent with the activation of a secondary splice site located near the deleted one. Is the secondary splice site within the exon (E) or its neighboring intron (I)? Write down E or I as your answer.