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Any of numerous eukaryotic organisms that are not fungi, plants, or animals and are chiefly unicellular or colonial. Protists that are multicellular do not have cells differentiated into tissues. The protists include the protozoans, certain algae, oomycetes, and slime molds.

[From New Latin Prōtista, former kingdom name, from Greek prōtista, neuter pl. of prōtistos, the very first, superlative of prōtos, first; see per in Indo-European roots.]

pro·tis′tan (-tĭs′tən) adj. & n.
pro′tis·tol′o·gy (prō′tĭ-stŏl′ə-jē) n.


(ˈprəʊtɪst) or


(Biology) (in some classification systems) any organism belonging to the kingdom Protista, originally including bacteria, protozoans, algae, and fungi, regarded as distinct from plants and animals. It was later restricted to protozoans, unicellular algae, and simple fungi. See also protoctist
[C19: from New Latin Protista most primitive organisms, from Greek prōtistos the very first, from prōtos first]


(ˈproʊ tɪst)

any of various complex one-celled organisms, of the kingdom Protista, that have nuclei and organelles and that are either free-living or aggregated into simple colonies: includes the protozoans, slime molds, and eukaryotic algae.
[1885–90; < New Latin Protista (neuter pl.) < Greek prṓtistos (masculine singular) the very first, superlative of prôtos first; see proto-]
pro•tis′tan, adj., n.
pro•tis′tic, adj.


Any of a large variety of usually one-celled organisms, including the protozoans, most algae, and the slime molds. Protists are eukaryotes (that is, they have cell nuclei) and live in water or in watery tissues of organisms. They are grouped as a separate kingdom in taxonomy. Also called protoctist. See Table at taxonomy.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.protist - free-living or colonial organisms with diverse nutritional and reproductive modes
microorganism, micro-organism - any organism of microscopic size
division Protista, Protista - eukaryotic one-celled living organisms distinct from multicellular plants and animals: protozoa, slime molds, and eukaryotic algae
References in periodicals archive ?
This disease is caused by a protist parasite of the genus Leishmania and is transmitted by the bite of a female phlebotomine sand fly.
Caption: Synchrotron scans of a fossil from China's Doushantuo formation (top) yield a 3-D image (bottom) showing three nuclei, indicating the fossil is not from an animal or embryo, but a protist.
According to the researchers of SUNY College of Environmental Science and Forestry's (ESF) International Institute for Species Exploration (IISE), the list includes a quartet of tiny newcomers to science: a miniscule skeleton shrimp from Santa Catalina Island in California, a single-celled protist that does a credible imitation of a sponge, a clean room microbe that could be a hazard during space travel and a teensy fringed fairyfly named Tinkerbell.
COMPARED to most of the new species on the list, the single-cell amoeboid protist is a giant, coming in at a staggering four to five centimetres tall.
The giant Cafeteria roenbergensis virus that infects a widespread marine phagocytic protist is a new member of the fourth domain of Life.
published in the Journal of Eukaryotic Microbiology, draws together the latest research to clarify the current state of protist diversity and categorization.
Problem Solver: I see the name of this chapter is Protist and Fungi.
The extent of protist diversity: insights from molecular ecology of freshwater eukaryotes.
of New York) assembles 22 articles on techniques reflecting recent advances in experimental tools for cytoskeleton research with emphasis on animal, plant, protist, and fungal model systems.
The protist fossil record is exquisitely detailed, allowing the authors to do exactly that.
ARS researchers have also assembled and maintain invertebrate protist collections at three research locations for the purpose of in-house and joint projects.
Complete genome of the uncultured Termite Group 1 bacteria in a single host protist cell.