Infection, Detection, Protection     Meet the Microbes
Pictures of Plasmodium and Giardia. What are they?!?: Protozoa are alive, but they are not part of the plant or animal kingdoms. Scientists gave protozoa a kingdom of their own. Mostly harmless: About 40,000 species of protozoa are known-only a few cause disease in people.
Big in a little world: Protozoa are the largest microbes, and they can be seen under a simple microscope. Super swimmers: Most protozoa live in moist habitats, from droplets of water in the soil to the ocean.