Why is it useful to study the ribosomal RNA of the three domains?
Answer
The ribosomal RNA is distinct between the three domains and can be used to trace evolutionary lineages.
The molecular make up for the ribosomal RNA is identical between the three domains proving the theory of a common ancestor.
The ribosomal RNA distinctions are easier to represent on paper than phylogenetic relationships.
The genetic make-up of the three domains is so similar that it makes it difficult to make genetic distinctions between species.

Question

Why is it useful to study the ribosomal RNA of the three domains?
Answer
		The ribosomal RNA is distinct between the three domains and can be used to trace evolutionary lineages.
		The molecular make up for the ribosomal RNA is identical between the three domains proving the theory of a common ancestor.
		The ribosomal RNA distinctions are easier to represent on paper than phylogenetic relationships.
		The genetic make-up of the three domains is so similar that it makes it difficult to make genetic distinctions between species.

anonymous · Answer

Because rRNA molecules throughout nature carry out the same function, their structure changes very little over time. Therefore similarities and dissimilarities in rRNA nucleotide sequences are a good indication of how related or unrelated different cells and organisms are. http://faculty.ccbcmd.edu/courses/bio141/lecguide/unit1/3domain/3domain.html