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

Answer 1

The answer is  : B

in order to answer this question, we just need to find out which organism has the simplest form

Unicellular  (organism that has only 1 cell) is more simple than multicellular so it eliminate option C and D

Prokaryote is more simple than eukaryote since prokaryote organism hasn't developed nucleus which make than organism could run complex activities. This eliminate option A

hope this helps

Answer 2

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