protist A single-celled, eukaryotic organism (see EUKARYOTE) that may resemble an animal or a plant. Animal-like protists include naked and shelled amoebas, foraminiferans, zooflagellates, and ciliates; plant-like protists include dinoflagellates, diatoms, and algae. In a 5-kingdom system of classification, protists were grouped as a kingdom, Protista; later some multicellular organisms with protist affinities but previously classed as fungi or plants were transferred into the Protista and the name of the kingdom was changed to Protoctista, a name sometimes used as a synonym for Protista.

protist A single-celled, eukaryotic organism (see EUKARYOTE) that may resemble an animal or a plant. Animal-like protists include naked and shelled amoebas, foraminiferans, zooflagellates, and ciliates; plant-like protists include dinoflagellates, diatoms, and algae. In a 5-kingdom system of classification protists were grouped as a kingdom, Protista; later some multicellular organisms with protist affinities but previously classed as fungi or plants were transferred into the Protista and the name of the kingdom was changed to Protoctista, although the new name is little used.

protist A member of the kingdom Protista.