The surfaces of the two ribosomal subunits that face one another contain the binding sites for the mRNA and incoming tRNAs and are thus of key importance for the function of the ribosomes.The fact that these surfaces consist largely of RNA supports what proposal?
A)the proposal that primordial ribosomes were composed solely of proteins
B)the proposal that primordial ribosomes were composed exclusively of RNA
C)the proposal that primordial ribosomes were composed exclusively of DNA
D)the proposal that prokaryotes gave rise to eukaryotes
E)the proposal that endosymbiosis gave rise to eukaryotes

Question

Quizplus · Accepted Answer

The fact that the surfaces of the ribosomal subunits that face one another contain largely RNA supports the proposal that primordial ribosomes were composed exclusively of RNA. This theory is known as the RNA world hypothesis, which suggests that RNA was the first self-replicating molecule and that early life forms may have relied solely on RNA for both information storage and catalytic activity.

The Surfaces of the Two Ribosomal Subunits That Face One