The Protozoa are considered to be a subkingdom of the kingdom Protista, although in the classical system they were placed in the kingdom Animalia. More than 50,000 species have been described, most of which are free-living organisms; protozoa are found in almost every possible habitat.

Is protozoa a phylum or a kingdom?

All protozoal species are assigned to the kingdom Protista in the Whittaker classification. The protozoa are then placed into various groups primarily on the basis of how they move. The groups are called phyla (singular, phylum) by some microbiologists, and classes by others.

What are the major group of kingdom protozoa?

Although protozoans are only made up of a single cell, these organisms manage to perform all the basic tasks of life. The protozoa are divided into four major groups: the ciliates, the flagellates, the heliozoans, and the amoebas.