The 28S, 18S and 5.8S forms of rRNA:
A) are encoded by three distinct genetic loci that are coregulated.
B) are encoded by three distinct genetic loci that are differentially regulated according to requirements for each rRNA.
C) are encoded by a single genetic locus whose transcript is subsequently processed.
D) are encoded by a single genetic locus whose transcript is differentially amplified.
E) are the result of alternate splicing of a single transcript.

Question

Quizplus · Accepted Answer

The 28S, 18S, and 5.8S forms of rRNA are transcribed as a single polycistronic unit from a single genetic locus known as the rDNA (rRNA-encoding DNA). This single transcript is subsequently processed by cleavage and modification to yield the three mature rRNA molecules.

The 28S, 18S and 5.8S Forms of RRNA