There are currently millions of species of single-celled organisms, and million of others that were once here and are now extinct. Which of these would BEST describe the first, most primitive organism to arise on Earth from which all other life evolved?

A)
unicellular eukaryote

B)
unicellular prokaryote

C)
multicellular eukaryote

D)
multicellular prokaryote

Question

There are currently millions of species of single-celled organisms, and million of others that were once here and are now extinct. Which of these would BEST describe the first, most primitive organism to arise on Earth from which all other life evolved?

A)
unicellular eukaryote	

B)
unicellular prokaryote	

C)
multicellular eukaryote	

D)
multicellular prokaryote

anonymous · Answer

So you're looking for the most primitive organism - which is simpler, a prokaryote or a eukaryote? Which is simpler - multicellular, or unicellular? Putting the two together should yield your response.

tetyana · Answer

In other words, as kma230 described, the answer is B. Pro- is Greek for "before" and -karyote is Greek for "kernel" or "nucleus." A prokaryote therefore existed before there ever was a nucleus (like eukaryotes have). Similarly, uni-cellular organisms are much simpler than multi-cellular so logically they came first as well.

anonymous · Answer

(B) uni cellular prokaryote ..as prokaryotes are usually devoid of nucleus like the E.Coli bacteria ..