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)There are more amino acids coded for by the DNA than by the mRNA.
C)The DNA represents a double- stranded structure,whereas the RNA is single- stranded.
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 between the length of the DMD gene (more than 2000 kb) and the mRNA produced by this gene (only about 14 kb) is likely due to the splicing out of introns during mRNA processing. Introns are non-coding regions of DNA that must be removed from the mRNA molecule before translation can occur. Therefore, the mRNA molecule contains only the coding regions of the gene (exons), resulting in a much shorter molecule than the original gene sequence.

It Has Been Recently Determined That the Gene for Duchenne