What is Protozoan?

It is an animal that has only one cell. They can not be seen with the naked eye. They live in the water and perform a valuable function in the habitat they live in. Some live in soil where a lot of water is present. One of their main sources of food is bacteria. Much of the bacteria they eat is harmful to other organisms. A protozoan has no brain. There are 4 main different types of protozoan, and over 65,000 species. Some algae and molds are in this category. Some use cilia to move, other shift inner fluid to move. For more information, look here: