The common ancestry (monophyly) of the three domains (Archaea, Bacteria, and Eukarya) is confirmed by
A) the similar appearances of different organisms.
B) ample fossil evidence.
C) DNA as the genetic material that encodes for proteins.
D) None of the above
E) All of the above

Question

Quizplus · Accepted Answer

DNA as the genetic material that encodes for proteins confirms the common ancestry of the three domains. This is because the genetic code is universal, meaning that the same nucleotide base pairs encode for the same amino acids in all living organisms, providing evidence for a common genetic ancestor. The similar appearances of different organisms and ample fossil evidence may suggest common ancestry, but they do not confirm it in the same way that DNA does. Therefore, options A and B are incorrect, and option D is incorrect because it implies that none of the answer choices are correct.

The Common Ancestry (Monophyly) of the Three Domains (Archaea, Bacteria