It has been recently determined that the gene for Duchenne muscular dystrophy (DMD)is more than 2000 kb (kilobases)in length; however,the mRNA produced by this gene is only about 14 kb long.What is a likely cause of this discrepancy?
A)The exons have been spliced out during mRNA processing.
B)The DNA represents a double-stranded structure,whereas the RNA is single-stranded.
C)More amino acids are coded for by the DNA than by the mRNA.
D)The introns have been spliced out during mRNA processing.
E)When the mRNA is produced,it is highly folded and therefore less long.

Question

Quizplus · Accepted Answer

The discrepancy is due to the removal of introns during mRNA processing. Introns are non-coding sequences that are present in the DNA but are removed during mRNA processing. This results in a shorter mRNA molecule that only contains the coding sequences (exons).

It Has Been Recently Determined That the Gene for Duchenne