Protists: the JUNK DRAWER Kingdom

If an organism doesn’t “fit” into another kingdom, it goes into kingdom Protista. Protists are simple, eukaryotic organisms that live in moist environments.

Three types Animal-like Plant-like Fungus-like

Animal-Like Protists Called Protozoans Heterotrophic Motile Unicellular vorticella

Helpful/Harmful Cause disease Food for other organisms

Protozoans classified by how they move: Giardia: Water containing cysts are consumed by people. The cysts burst inside the small intestine and attach with suckers to the intestinal lining. There they rapidly reproduce, inhibiting the intestine’s ability to digest food. Causes stomach pain, diarrhea, lack of appetite. Each year 30,000 people are infected Protozoans classified by how they move: Ciliates – move with hairlike cilia. Pseudopods – move with a “foot”. Zooflagellates – move with a whiplike tail.

Plant-like Protists Called Algae Autotrophic May be unicellular or multicellular

Provide home for organisms Additive in food; the source of carageenan – a thickener in pudding, ice-cream, etc. Diatoms; tiny and bountiful – may be a million to a liter of water. Added as abrasives in cleaners, detergents, etc.

Algae and the environment: Very sensitive to environmental conditions – they will change position in the ocean in response to temperature change. Often the beginning of a food chain. Red tide – caused by dinoflagellates.

Fungus-like Protists Water molds and slime molds Heterotrophic Motile Reproduce with spores Watermold on mayfly larvae

Responsible for the potato famine in Ireland in 1845, killing over one million people.

Amoeba Don’t ever tease a wee amoeba By calling him a her amoeba. And don’t call her a he amoeba Or never he a she amoeba. ‘Cause whether his or hers amoeba, They too feel like you and meba.