Kingdom Protista

General Characteristics Any organism not classified as a—plant, animal, fungus, or bacteria (prokaryote). Protists are eukaryotic having a distinct nucleus and organelles. Most protists are unicellular (one-celled) but some are multicellular.

4. Protists are primarily classified according to how they obtain nutrition: Animal-like—heterotrophs (eat other organisms) b. Plant-like—autotrophs They contain chloroplasts and make their own food (photosynthesis). Fungus-like— Decomposers/Heterotrophs Didinium Paramecium eating Green like plants! Water mold

Animal-like Protists (Protozoans) Method of Movement: Cilia—hair-like projections used for movement and feeding Cytoplasmic streaming—pseudopod (false foot) extends and cytoplasm streams into it. Video Video

2. Paramecium: Contractile Vacuole Nucleus Cilia Oral Groove 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)

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

Beneficial Recycles nutrients by breaking down dead matter Food source—for other organisms Mutualism—both organisms benefit Example: Trichonympha—makes it possible for termites to eat wood. Termites do not have the enzymes to digest wood.

a. Flagellum—whip-like structure used for movement 2. Euglena: Plant-like Protists 1. Method of Movement: a. Flagellum—whip-like structure used for movement 2. Euglena: Eyespot For photosynthesis (light) Flagella Nucleus Contractile Vacuole Chloroplasts

Unicellular Algae: Phytoplankton provides a source of nourishment for other organisms b. Protists recycle sewage and waste materials.

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.

Multicellular Algae: Examples--- Red Algae Green Algae Brown Algae

Uses of Algae: Algae is a good food source for life in the oceans. Algae produces much of Earth’s oxygen through photosynthesis. Algae is used to make sushi, ice cream, salad dressing, plastics, paint, agar.

Fungus-like Protists: Examples— Slime molds Water molds

Importance of Fungus-like Protists: Beneficial— Recycles dead organic material. Results in rich, topsoil providing nutrients for plants.

Harmful— P. Infestans (water mold) caused Great Potato Famine in Ireland. This lead to the mass starvation of 1 million Irish people.