Monday, August 6, 2012

A protozoan is a unicellular microorganism which live freely in water or as a parasitic entity in a multi-cellular organism. Some protozoa, like Trypanosoma gambiense and Trypanosoma cruzi, can cause dangerous diseases, such as the African trypanosomiasis (or sleeping sickness) and Chagas disease, respectively. Other protoza which cause diseases in men are Plasmodium (malaria), Entamoeba histolytica (dysentery), and Toxoplasma gondii (toxoplasmosis). Although they are single-celled organism, they have animal-like behavior and are endowed with a tail-like process, called flagella, with which the propelled themselves in a liquid environment. Protozoa range in size from 10 to 50 micrometers.