Question 1
Paper 2Easy5 marksResearchers examine mature mRNA produced from the same gene in two cell types. The exons present in each mRNA are shown.
| Cell type | Exons in mature mRNA |
|---|---|
| X | 1, 2, 4 |
| Y | 1, 3, 4 |
(a)[1]
Identify the exon present in the mRNA from cell type X but absent from the mRNA from cell type Y.
(b)[2]
State the two exons present in both mRNAs.
(c)[2]
Using the table, explain how this gene can code for different polypeptides.