What Do the Genetic Comparisons Among Modern Organisms Indicate

Question

What do the genetic comparisons among modern organisms indicate?  
A) All modern life descended from the same cellular ancestor.
B) The evolution of DNA-based systems was preceded by an interval during which RNA was the genetic material.
C) All modern life descended from multiple differing unicellular ancestors.
D) Genes governing information processing are most like those of archaea, and genes related to metabolism are most like those of bacteria.
E) Chemoheterotrophs gave rise to all modern organisms.

Accepted Answer

Genetic comparisons among modern organisms, as well as the fossil record, support the theory that all modern life descended from a common ancestor, which was a primitive, single-celled organism. This idea is known as the theory of universal common ancestry.