Themes > Science > Zoological Sciences > Animal Phyla and Included Classes > Sub-Kingdom: Protozoa > Sub-kingdom: Protozoa

"Protozoa are a diverse assemblage of unicellular organisms with puzzling affinities. They are distinctly animal-like in several respects: they lack a cell wall, have at least one motile stage in the life cycle, and most ingest their food. Throughout their long history, protozoa have radiated to generate a bewildering array of morphological forms within the constraint of a single cell."

Hickman, C.P. and L.S. Roberts.  1994.  Biology of Animals, Sixth Edition.  Wm.C.Brown Publishers:  Dubuque, Iowa.  Page 409.   

..Phylum Sarcomastigophora - Locomotion via flagellum, pseudopodia, or both. Usually only one type of nucleus.
..Subphylum Mastigophora - One or more flagella typically present in adult stages. Autotrophic or heterotrophic or both. Reproduction usually asexual by fission.
Example: Euglena

..Subphylum Sarcodina - Pseudopodia typically present, flagella present in developmental stages of some.
Example: Amoeba

..Phylum Ciliophora - Cilia or ciliary organelles in at least one stage of life cycle. Two types of nuclei, with rare exceptions. Reproduction by binary fission and conjugation.
Example: Paramecium      
..Phylum Apicomplexa - Cilia and flagella usually absent, cysts often present. All species are parasitic.
Example: Plasmodium


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