Which kind of DNA should provide the best molecular clock for determining the evolutionary relatedness of several species whose common ancestor became extinct billions of years ago?
A) that coding for ribosomal RNA
B) intronic DNA belonging to a gene whose product performs a crucial function
C) paralogous DNA that has lost its function (i.e., no longer codes for functional gene product)
D) mitochondrial DNA
E) exonic DNA that codes for a noncrucial part of a polypeptide

Question

Quizplus · Accepted Answer

Ribosomal RNA (rRNA) genes are highly conserved across different species due to their essential role in protein synthesis. This conservation makes them excellent molecular clocks for studying evolutionary relationships over long periods, including those species whose common ancestors became extinct billions of years ago.

Which Kind of DNA Should Provide the Best Molecular Clock