Protoctista


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Pro·toc·tis·ta

(prō'tok-tis'tă),
A kingdom of eukaryotes incorporating the algae and the protozoans that comprise the presumed ancestral stocks of the fungi, plant, and animal kingdoms; they lack the developmental pattern stemming from a blastula, typical of animals, the pattern of embryo development typical of plants, and development from spores as in the fungi. Included in Protoctista are the nucleated algae and seaweeds, the flagellated water molds, slime molds, and slime nets, and the protozoa; unicellular, colonial, and multicellular organisms are included, but the complex development of tissues and organs of plants and animals is absent. The term Protoctista replaces the term Protista, which connotes single-celled or acellular organisms, whereas the basal preplant (Protophyta) and preanimal (Protozoa) assemblages incorporated in Protoctista include many multicellular forms, because multicellularity appears to have evolved independently a number of times within these primitive groups.
[G. prōtos, the first, + ktizō, to establish]

Pro·toc·tis·ta

(prō'tok-tis'tă)
A kingdom of eukaryotes incorporating the algae and the protozoans that comprise the presumed ancestral stocks of the fungi, plant, and animal kingdoms; they lack the developmental pattern stemming from a blastula (typical of animals), the pattern of embryo development (typical of plants), and development from spores as in fungi. Included are the nucleated algae and seaweeds, the flagellated water molds, slime molds and nets, and protozoa; unicellular, colonial, and multicellular organisms are included, but the complex development of tissues and organs of plants and animals is absent.
[G. prōtos, the first, + ktizō, to establish]

Protista

or

Protoctista

the kingdom, in older CLASSIFICATIONS, which contains eukaryotic, mostly unicellular, organisms, including ALGAE, diatoms (BACILLARIOPHYCEAE), PROTOZOANS and slime moulds.
References in periodicals archive ?
However, the term 'microbenthos' fits better the bottom-inhabiting unicellular Protoctista.
The question of how many kingdoms should be recognized is unresolved, related to the heterogeneous membership of the Protoctista (Protista).
I agree that a resolution to the number of kingdoms (or domains) is indeed possible, and that sorting out the evolutionary relationships among members of tire Kingdom Protoctista will be an essential step in doing so.