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Biology II. Protists. General Characteristics. Any organisms not classified as a plant, animal, fungus, or bacteria. Protists are eukaryotic having a distinct nucleus and organelles Most protists are unicellular but some are multicellular. Similar to Bacteria. Unicellular
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Biology II Protists
General Characteristics • Any organisms not classified as a plant, animal, fungus, or bacteria. • Protists are eukaryotic having a distinct nucleus and organelles • Most protists are unicellular but some are multicellular
Similar to Bacteria • Unicellular • One of the first groups of living things on Earth • Microscopic • Can cause diseases • Can be a parasite
Different from Bacteria • Has a nucleus • Live in watery environment • Generally live as individual cells • Protists vary greatly in appearance and function.
3 Categories of Protists • Animal-like protists • Plant-like protists • Fungus-like protists
Animal Like Protists • Protozoan means “First Animal” • Cells contain a nucleus • Cells lack a cell wall • They are heterotrophs • Most can move on their own • Eat other organisms just like animals
4 Groups of Animal Like Protists • Sarcondines • Ciliates • Flagellates • Sporozoans
Sarcodines • Have pseudopods (False Foot) • Extensions of the cell membrane and cytoplasm • Pseudopods are used for movement and to capture food • Many have shells • These shells form limestone, marble and chalk • Example: Amoeba
Ciliates • Have cilia on the outside of their cells • Tiny hair like projections used for movement, to gather food, and to feel objects around them • Example: Paramecium
Flagellates • Have a flagellum that is used for movement of the protist • Many live in animals • Symbiosis: a close relationship where at least one organisms benefits • Mutualism: when both organisms benefits
Sporozoans • All sporozoans are parasites • They feed on cells and body fluids • Form from spores (tiny reproductive cells) • Pass from one host to another • Such as ticks, mosquitoes, or other animals to humans.
Importance of Animal-Like Protists • Beneficial • Recycles nutrietns by breaking down dead matter • Food source- for other organisms • Mutualism- both benefit
Plant-Like Protists • Unicellular and Multicellular • They contain chloroplasts and make their own food (photosynthesis) • Can move on their own • 70% of the earth’s oxygen is produced by plant-like protists
6 Groups of Plant Like Protists • Euglenoids • Diatoms • Dinoflagellates • 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 • Heterotrophs • Have cell walls • Many have flagella and are able to move at some point in their lives • Three types: Slime molds, Water & Downy molds • Reproduce with Spores
Importance of Fungus-Like Protists • Beneficial • Recycles dead organic material. • Which results in rich, topsoil providing nutrients for plants. • Harmful • Water mold caused the Great Potato Famine in Ireland