Question

Why is rRNA such a useful tool in molecular systematics?

A. Only advanced organisms have rRNA, so it is a useful derived character.
B. It evolves quite rapidly.
C. It evolves quite slowly, allowing comparisons to be made between distantly related organisms such as eukaryotes and bacteria.
D. It doesn't change at all, so it is a useful control to ensure that the sequence data is accurate.

Answer 1

rRNA is valuable in molecular systematics due to its slow evolutionary rate, allowing for comparison among widely divergent species by providing a reliable molecular record for constructing phylogenetic trees.

Step-by-step explanation:

rRNA, or ribosomal RNA, is a useful tool in molecular systematics because it evolves quite slowly.

This characteristic allows for comparisons to be made between distantly related organisms, like eukaryotes and bacteria.

The slow evolution of rRNA means that it is able to provide a reliable molecular record, tracing back to common ancestors among diverse groups of organisms.

This ancient, preserved molecular data is critical for constructing the phylogenetic trees that underlie our understanding of evolutionary relationships.

Moreover, because rRNA is a fundamental component of the ribosome, found in all life forms, it serves as a universal marker for comparative genetics.