Use the Following Model of a Eukaryotic Transcript to Answer

Multiple Choice

Use the following model of a eukaryotic transcript to answer the question. E1-4 refer to the exons and I1-3 refer to the introns in the pre-mRNA transcript.
5' UTR E1 I1 E2 I2 E3 I3 E4 UTR 3'
Suppose that exposure to a chemical mutagen results in a change in the sequence that alters the 5' end of intron 1 (I1) . Which of the following results might occur?

A) loss of the gene product
B) loss of E1
C) premature stop to the mRNA
D) inclusion of I1 in the mRNA