Protista

The Kingdom Protista (one of the five kingdoms in [[biology|Linnaean Taxonomy]]) includes all the [[Eukaryote|Eukaryotes]] except for the [[Plantae]], [[Fungi]], and [[Animalia]].  A few forms are multicellular, ie the [[Phaeophyta]] (brown algae) and [[Rhodophyta]] (red algae).  The vast majority, though, are single-celled and are typically only 0.01-0.5 mm in size, too small to be seen without a microscope.  Protists are ubiquitous throughout aqueous environments and the soil, commonly surviving dry periods in the form of ''cysts''; a few are important parasites.

Traditionally protists have been divided into:
* Plant-like forms that have chloroplasts, the [[Algae]];
* Fungus-like forms, the [[Slime mold|Slime molds]] and [[Oomycota]];
* Animal-lie forms, the Protozoa, generally divided on the basis of morphology and locomotion into:
** [[Flagellate|Flagellates]]
** [[Amoeboid|Amoeboids]]
** [[Sporozoa|Sporozoans]]
** [[Ciliates]]
Except for the ciliates and Oomycota, these are all polyphyletic and frequently overlapping.  More recently protists have been divided into more genuine groups on the basis of ultrastructural and chemical features.  Aside from basal forms, these can be assorted into a few broad categories on the basis of the the form of the [[mitochondria]] and in particular the [[cristae]] within them.

One of the standard, and heavily inadequate, break-ups into phyla:

 Phylum Caryoblastea=Pelobionta ([[Pelobionts]])
 Phylum [[Dinoflagellata]]
 Phylum [[Rhizopoda]] (polyphyletic - see [[Amoeboid]], especially [[Ramicristates]])
 Phylum Chrysophyta (basal [[Stramenopiles]]
 Phylum Haptophyta=Prymnesiophyta ([[Haptophytes]])
 Phylum Euglenophyta ([[Euglenids]]) 
 Phylum Cryptophyta ([[Cryptomonads]])
 Phylum Zoomastigina (polyphyletic - see [[Flagellate]] for now)
 Phylum [[Xanthophyta]]
 Phylum [[Eustigmatophyta]]
 Phylum Bacillariophyta ([[Diatoms]])
 Phylum Phaeophyta (brown algae)
 Phylum Rhodophyta (red algae)
 Phylum Chlorophyta (basal [[Plantae]])
 Phylum Actinopoda (polyphyletic - see [[Amoeboid]] for now)
 Phylum [[Granuloreticulosa]]
 Phylum [[Ciliates|Ciliophora]]
 Phylum [[Apicomplexa]]
 Phylum [[Myxozoa]]=Cnidosporidia
 Phylum Labyrinthulomycota=Labyrinthulida ([[Labyrinthulida]])
 Phylum Acrasiomycota (polyphyletic)
 Phylum [[Myxomycota]]
 Phylum Plasmodiophoromycota=Plasmodiophorida
 Phylum [[Hyphochytridiomycota]]
 Phylum [[Oomycota]]