What is a Protist? Unicellular or multicellular Microscopic or very large Heterotrophic or Autotrophic What do they have in common? –All protists are eukaryotic, meaning they have membrane bound organelles. (like us!) Live in moist environments. Categorized by their method of nutrition. g3sywC7k

Animal-like Protists Called protozoa (protozoan singular) All protozoa are unicellular Heterotrophic Are grouped on how they move –Cilia (Ciliates) Reproduce asexually and use its cilia, oral groove, gullet and food vacuoles in the process of digestion –Flagella (Flagellates) African Sleeping sickness, help termites digest wood –Cytoplasm containing pseudopodia (Amoeboid) Amoebas reproduce asexually and can form cysts in extreme conditions One group causes disease called sporozoans –Most produce spores (a reproductive cell that forms without fertilization and produces a new organism) –Parasites –300 Million people globally have Malaria Examples: –Paramecium –Foraminiferans –Amoebas atch?v=F_Xi3hnhtbg

Fungus-like Protists Decompose dead organisms Heterotrophic / Decomposers Unlike Fungi… –Can move around during some point in their life –Do not have chitin in their cell walls Examples: –Slime Molds –Water Molds –Downy Mildews om/watch? v=9pNGh W9BiZE Ewww.. we’re gross! Dude, I know.

Plant-like Protists Called algae (alga singular) Do not have organs like roots, stems and leaves Produce most of the Oxygen in the atmosphere and the basis for aquatic food chains. Undergo the process of photosynthesis to make their own food (Autotrophic) –Note: Euglena can also be heterotrophic Examples: –Euglena –Diatoms (silica shells) –Dinoflagellates (red tides) –Red, Brown, Green algae Green algae were likely ancestral plants. be.com/watch?v =0rNI8Bos_BQ& feature=related

Plant-like Protists: Alternation of Generations The life cycles of some algae and all plants have a pattern called alternation of generations. Alternates between haploid and diploid generations Haploid form is called the gametophyte because it produces gametes. The gametes fuse to form a zygote which form the diploid part of the organism is called the sporophyte. Eventually these cells become haploid spores that can develop into a new gametophyte. 06/protista.htm