Bacteria and other prokaryotes are found deep underground, in water, and in the air. One micron (1026 m) is a typical length scale associated with these microbes.
(a) Estimate the total number of bacteria and other prokaryotes in the biosphere of the Earth.
(b) Estimate the total mass of all such microbes.
(c) Discuss the relative importance of humans and microbes to the ecology of planet Earth. Can Homo sapiens survive without them?