Ribosomes contain one copy each of 5.8S, 18S, and 28S rRNA. The major mechanism ensuring that each is produced in equal molar amounts is the
A) selective degradation of excess transcripts of the respective rRNAs.
B) grouping of the DNA sequences encoding each rRNA into a single rRNA gene.
C) outcome of coevolution of the separate genes.
D) existence of common sequence features for transcription initiation for the genes encoding each rRNA.

Question

Quizplus · Accepted Answer

The grouping of the DNA sequences encoding each rRNA into a single rRNA gene ensures that each is produced in equal molar amounts. This is because the transcription of the entire rRNA gene produces a precursor transcript containing all three rRNAs, which are then processed into their mature forms. Thus, the transcription and processing of each rRNA is coordinated within the context of the larger rRNA gene.

Ribosomes Contain One Copy Each of 5