KINGDOM PROTISTA

First appeared 1.5 billion years ago Eukaryotic Found in fresh or salt water Unicellular Lack specialized features No embryos or complex sex organs Most aerobic

CLASSIFIED INTO THREE DIFFERENT GROUPS: Animal-like Protists (Protozoan – means First Animal) heterotrophs  ingest food from surrounding Vary in size (2 цm  5 cm) and form Can be parasitic Aquatic

Four Phyla based on method of Locomotion A) Sarcodines amoeboid movement by pseudopods (False Feet)  cytoplasmic extension and retraction of pseudopods to engulf food particles

Amoeba movement

B) Flagellates whip like flagella most are parasitic and cause disease in animals some have chloroplasts ex. Euglena, trypanosomes, giardia

C) Ciliates hair like for synchronized swimming reproduce asexually by binary fission sexually by conjugation ex. Paramecium, stentor, vorticella Movement video cilia and flagellum

D) Sporozoans non- motile, depend on body fluids of host for movement all parasitic complex life cycles ex. Plasmodium viviax (malaria) see pg. 355 fig. 10

Plant – like Protists autotrophic  contain chlorophyll and are photosynthetic pigments Unicellular or multicellular Aquatic 6 phyla based on type of chloroplasts and pigments E.g. euglena, algae

Fungus–like Protists Referred to as slime moulds Most are saprotrophic (live dead organic matter) Aquatic or terrestrial Some are parasites E.g. plasmodium

IMPORTANCE OF PROTISTS Found almost everywhere in the biosphere Provide a food source for other organisms (even other protests) Algae perform 50% to 75% of all photosynthesis on Earth and so produce most of the world’s free oxygen Algae also provides agar, which is used in drug capsules, gels and cosmetics Diatoms contain silica, which is used in insulation and filtration materials Algae are instrumental in the creating of petroleum resources