The lowest of the grand divisions of the animal kingdom.
plural of alga.
in some classifications considered a superphylum or a subkingdom; comprises flagellates; ciliates; sporozoans; amoebas; foraminifers
primitive chlorophyll-containing mainly aquatic eukaryotic organisms lacking true stems and roots and leaves
Protozoa (also protozoan, plural protozoans) is an informal term for a group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic tissues and debris. Historically, protozoans were regarded as , because they often possess animal-like behaviours, such as motility and predation, and lack a cell wall, as found in plants and many algae.
Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades.