Protozoa is the largest microbe, only a few out of 40,000 Protozoa are known to be dangerous. Protozoa lives in oceans wet dirt creeks, and ponds pretty much anything wet. Most parasitic protozoa in humans are less than 50 μm in size . The smallest (mainly intracellular forms) are 1 to 10 μm long, but Balantidium coli may measure 150 μm. Pr otozoa (pro-toe-ZO-uh) are one-celled organisms, like bacteria . But they are bigger than bacteria and contain a nucleus and other cell structures, making them more like plant and animal cells. Unlike plants, fungi and most types of algae, protozoans do not typically have a rigid cell wall , but are usually enveloped by elastic structures of membranes that permit movement of the cell . ... The pellicle gives some shape to the cell , especially during locomotion. According to google. Now here are some videos and information pages https://microbiologysociety.org/why-microbiology-matters/what-is-microbiology/protozoa.html https://en.m.w
