1. Any organism not classified as a—plant, animal, fungus, or bacteria (prokaryote). 2. Protists are eukaryotic having a distinct nucleus and organelles. 3. Most protists are unicellular (one-celled) but some are multicellular. 4. Protists are primarily classified according to how they obtain nutrition: a. Animal-like—heterotrophs (eat other organisms) b. Plant-like—autotrophs They contain chloroplasts and make their own food (photosynthesis). Didinium eating Paramecium Green like plants! a. Fungus-like— Decomposers/Heterotrophs Water mold Animal-like Protists (Protozoans) 1. Method of Movement: a. Cilia—hair-like projections used for movement and feeding b. Cytoplasmic streaming—pseudopod (false foot) extends and cytoplasm streams into it. Video Video 2. Paramecium: Contractile Vacuole Collects and removes excess H2O (Maintains homeostasis) Nucleus Cilia Oral Groove Used to collect food Cell Membrane 3. Amoeba: Nucleus Contractile Vacuole Pseudopod (False foot) 4. Importance of Animal-like Protists: a. Harmful i. Disease-causing parasites spread by insect bites 1. Malaria—Plasmodium spread by mosquito 2. African Sleeping Sickness— Trypmosoma spread by Tsetse fly Video 2:56 b. Beneficial i. Recycles nutrients by breaking down dead matter ii. Food source—for other organisms iii. Mutualism—both organisms benefit Example: Trichonympha—makes it possible for termites to eat wood. Termites do not have the enzymes to digest wood. Plant-like Protists 1. Method of Movement: a. Flagellum—whip-like structure used for movement 2. Euglena: Eyespot For photosynthesis (light) Nucleus Flagella Video Contractile Vacuole Chloroplasts 3. Unicellular Algae: a. Phytoplankton provides a source of nourishment for other organisms b. Protists recycle sewage and waste materials. C. Algal blooms are harmful when overgrown—deplete water of nutrients consequently killing fish. Algal blooms called Red Tides cause illness, paralysis, and death of fish and even humans. 4. Multicellular Algae: a. Examples--i. Red Algae ii. Green Algae iii. Brown Algae 5. Uses of Algae: a. Algae is a good food source for life in the oceans. b. Algae produces much of Earth’s oxygen through photosynthesis. c. Algae is used to make sushi, ice cream, salad dressing, plastics, paint, agar. Fungus-like Protists: 1. Examples— a. Slime molds b. Water molds 2. Importance of Fungus-like Protists: a. Beneficial— Recycles dead organic material. Results in rich, topsoil providing nutrients for plants. b. Harmful— P. Infestans (water mold) caused Great Potato Famine in Ireland. This lead to the mass starvation of 1 million Irish people.