Protozoa (Heterotroph, Eukaryotic)

Synonyms

Protist (pro parte); Protoctista (pro parte)

Definition

Protozoa (historical) Animals that can be reduced to the status of one cell.

Protozoa (modern) All eukaryotes after exclusion of the derived kingdoms such as Animalia, Fungi, Plantae, and Chromista.

Introduction

Protozoa are a loose grouping of organisms with similar (usually unicellular) organization and heterotrophic mode of nutrition. They are found in most soils, fresh water, and oceans. As components of the micro- and meiofauna, Protozoa are important consumers of bacteria and an important food source for microinvertebrates. While most are solitary individuals, various colonial forms exist. The taxonomic relationships of protozoans to one another and to other protists continue to be revised. Most are free-living, but some are commensalistic, mutualistic, or parasitic. Pathogenic Protozoa include species of Plasmodium, the cause of human malaria, Trypanosoma gambiense, the cause of African trypanosomiasis, and Entamoeb...