Chapter 20

What is a protist? any organism that is not a plant, animal, fungus, or prokaryote. Domain Eukarya, Kingdom Protists Eukaryotic – HAVE A NUCLEUS Mostly unicellular Heterotrophic or autotrophic Aquatic or moist habitats

Heterotrophic feed on bacteria, organic matter, other protozoans, and fungi

Grouped according to movement Sarcodines – move by pseudopod “false feet” Ciliates – move with cilia Tiny hair-like projections Zooflagellates – move by flagella Long whip-like structure Sporozoans - parasitic

Autotrophic – carry out photosynthesis

Phytoplankton (small, unicellular algae found near the surface of bodies of water) produce about 75% of the Earth’s oxygen Basis of most aquatic food chains

Dinoflagellates Red tides – increased nutrients cause protists to grow out of control Some species produce a strong nerve toxin that gets into shellfish and can harm you if you eat it.

Diatoms cell walls made of silicon used to make toothpaste abrasive and road paint

Algae used in sushi, ice cream, agar, deodorant, hair conditioner, salad dressing, pudding

Fungus-like protists decomposers, have cell walls, and reproduce by spores slime molds, water molds, and mildew Attack potatoes, cabbage, and corn The Great Hunger was caused by this group of protists

Plasmodium—carried by Anopholes mosquito causes malaria Trypanosoma—carried by the tsetse fly causes African sleeping sickness Giardia, Entamoeba, Cryptosporidium causes amoebic dysentery Diseases cause by Sporozoans :

Toxoplasma gondii Causes toxoplasmosis, can be contracted from an infected cat or poorly cooked meat. Harmful to a developing fetus.