Question

You are studying a eukaryotic gene whose initial transcript is 1500 nucleotides in length. The mature mRNA derived from the gene is 1200 nucleotides in length. What is the most probable reason for the discrepancy?
a) a mutation that results in a shorter product
b) a mutation that results in a shorter product or mRNA breakage could have occurred.
c) mRNA breakage
d) removal of exons
e) removal of introns

Answer 1

Answer

Option E

Explanation

Nucleotide sequence in 3s code for amino acids which further form peptide, polypeptide, and protein. But not all these nitrogenous bases actually code for protein, some of them are non-protein coding sequence (called introns) which are of course removed to make the mRNA shorter than the gene.