The Amoeba proteus, commonly called the Amoeba is the representative of this formless group of organisms. These organisms are parasitic and free living. The species Entamoeba histolytica , can cause a serious disease in humans if it finds its way into the intestine. These organisms do not contain cilia or flagella. They reproduce by binary fission.
Zooflagellates contain whip-like flagella.
They are either free living or parasitic. Termites cannot live without a certain zooflagellete in their intestine producing cellulose digesting enzymes. Trypanosomes, which live in the blood of vertebrates, cause sleeping sickness. Sleeping sickness is occurs when a person is bitten by the tsetse fly. All sporozoans are parasitic.