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]
Farlex Partner Medical Dictionary © Farlex 2012

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]
Medical Dictionary for the Health Professions and Nursing © Farlex 2012

Protista

or

Protoctista

the kingdom, in older CLASSIFICATIONS, which contains eukaryotic, mostly unicellular, organisms, including ALGAE, diatoms (BACILLARIOPHYCEAE), PROTOZOANS and slime moulds.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005
References in periodicals archive ?
In the 1950s, biologists classified organisms into five kingdoms: Monera (bacteria), Protista (later, Protoctista, comprising algae, slime molds, protozoans), Fungi (molds, mushrooms, lichens), Plantae (flowering and cone-bearing plants, ferns, mosses), and Animalia (vertebrate and invertebrate animals).
Handbook of Protoctista. Jones & Bartlett, Boston, Massachusetts, USA.
The eukaryotic microbes, amitochondriate heterotrophs, are wood-ingesting motile protists (phylum Archaeprotista, class Parabasalia, kingdom Protoctista), whereas the attached prokaryotes are recognized by morphology and motility (live, videography, light and electron microscopy) as spirochetes: phylum Spirochae-tae of the kingdom Prokaryotae (Margulis, 2000; Margulis and Chapman, 2010).