Chapter 21: Protista

The Kingdom Protista A. What is a Protist? 1. Eukaryotes that do not fit in the plant, animal or fungus kingdom. - Cannot be classified as animals, plants or fungi, but share many characteristics with plants (algae), animals (protozoan) and fungi (slime molds) 2. Have a nucleus with DNA and membrane bound organelles. 3. Most are unicellular, but some are multicellular (algae)

The Kingdom Protista A. What is a Protist Continued? 4. Mobility - flagella - cilia - pseudopod 5. Can be photosynthetic or heterotrophic 6. Most- asexual reproduction- binary fission OR Sexual reproduction through conjugation. Protista video

B. Evolution of Protists. Lynn Margulis hypothesized that B. Evolution of Protists Lynn Margulis hypothesized that eukaryotic cells evolved from prokaryotic cells. Known as the Endosymbiotic Theory Video 1 Animation Video 2

II. Animal-Like Protists: Protozoans A. Protozoan Phyla- classified by their method of movement 1. Move using flagella - Absorb food through their cell membranes (decaying organic material) - Live in lakes and streams, or in other organisms - Reproduce asexually or sexually, by forming gametes Ex:Trypanosomes - cause African sleeping sickness Video

II. Animal-Like Protists: Protozoans A. Protozoan Phyla- classified by their method of movement. 2. Move using pseudopods (temporary projections of cytoplasm) - Also known as a false foot. - Amoebas eat by surrounding their food with their pseudopods and forming food vacuoles. - Known as phagocytosis. Example: Amoebas - amoebic dysentery (Entamoeba)

Feeding amoeba Feeding amoeba 2 http://www.enchantedlearning.com/subjects/protists/amoeba.shtml Feeding amoeba Feeding amoeba 2 http://www.microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-uk.org.uk/mag/artsep01/amoeba.html

II. Animal-Like Protists: Protozoans A. Protozoan Phyla- classified by their method of movement. 3. Move using cilia (hair-like extensions) - Found in fresh and salt water - Most are free-living. - Feed by an oral groove. - Contractile vacuole – used to pump out excess water. Example: Paramecium Video

III. Plant-like Protists A. Unicellular Algae - Contain chlorophyll and accessory pigments to harvest the energy from the sunlight. - Contain eyespot. - No cell wall. - Found in ponds and lakes. - Move by a flagellum - Example: Euglena video

B. Red, Brown, and Green Algae 1. Most are multicellular 2. Differ in their photosynthetic pigments 3. Uses of Algae a. Food for other organisms b. Humans use/eat algae product (ice cream, salad dressing, pudding and candy bars) c. Used to make plastics, waxes, deodorants, paint and artificial wood. d. Chemicals in algae can be used to treat high blood pressure, arthritis, and other health problems. Volvox video Mixed Protists video

IV. Fungus-like Protists A. Characteristics 1. Heterotrophs that absorb nutrients from dead or decaying matter. 2. Lack Chitin cell walls like true fungus B. Examples - slime molds and water molds

Kingdom Fungi Eukaryotes. Multicellular, except yeast. Absorptive heterotrophs (digest food outside their body & then absorb it). * decomposers Feed by releasing digestive enzymes to break down food. Cell walls made of chitin. Molds and mushrooms are also examples. Asexual reproduction by spreading of spores. Sexual reproduction Produce antibiotics to help fight bacterial diseases. Fungi video

Spores - Reproductive cells that form new organisms without fertilization