What makes ribosomal RNA useful as a molecular clock? (2 points) A large portion of the DNA ring is not vital to structure or function, allowing it to accumulate neutral mutations. Its rate of mutation increases over time as organisms continue to evolve and differentiate from each other. A slow mutation rate makes it useful for determining evolutionary relationships between ancient species. It is only found in select organisms, making it easier to compare relationships between species that have it.

The correct statement is that a slow mutation rate makes it useful for determining evolutionary relationships between ancient species.

Explanation:

The rRNA or ribosomal RNA has an application as a molecular clock because of many factors. It exhibits a very slow mutation rate, that is, around one million years because of which it stays highly conserved in all the organisms. In the ribosomal RNAs of two organisms, the degree of mutations can be associated directly with the time they were originated in the past.  

In supplementation, it possesses essential biological function because of which it can be witnessed in almost all the species.