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) There are more amino acids 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 between the length of the gene and the mRNA is due to the splicing out of the introns during mRNA processing. The introns, non-coding regions of DNA, are transcribed into RNA along with the exons, coding regions of DNA. However, during mRNA processing, the introns are spliced out by the spliceosome, leaving only the exons to form the mature mRNA. This results in a shorter mRNA than the original length of the gene.

It Has Been Recently Determined That the Gene for Duchenne