Microbiology--classifying microorganisms

A staggering diversity of microorganisms becomes visible through the microscope; a simple approach to classification makes sense of this mind-boggling array of life. The key: divide life into prokaryotes (cells without nuclei) and eukaryotes is further subdivided into groupings; amoebas, flagellates, ciliates, algae, and others reflecting the early branchings of the eukaryotic line.