The following mRNA sequence is taken from the middle of exon 3 in a mature mRNA that has 12 exons. Knowing that this mRNA does not undergo nonsense-mediated decay, which of the reading frames shown is the correct one for this mRNA? Write down 1, 2, or 3 as your answer.

Question

Quizplus · Accepted Answer

Frames 2 and 3 contain a stop codon (UAG at the sixth codon, UGA at the first codon, respectively), which is not consistent with the sequence coding for a protein.

The Following MRNA Sequence Is Taken from the Middle of Exon