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Ch. 20 Protists

Ch. 20 Protists. Ch. 20 Outline. 20-1: The Kingdom Protista What is a Protist Classification of Protists 20-2: Animal-like Protists: Protozoans Zooflagellates Sarcodines Ciliates Animal-like Protists and Disease Ecology of Animal-like Protists. Ch. 20 Outline.

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Ch. 20 Protists

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  1. Ch. 20 Protists

  2. Ch. 20 Outline • 20-1: The Kingdom Protista • What is a Protist • Classification of Protists • 20-2: Animal-like Protists: Protozoans • Zooflagellates • Sarcodines • Ciliates • Animal-like Protists and Disease • Ecology of Animal-like Protists

  3. Ch. 20 Outline • 20-3: Plant-like Protists: Unicellular Algae • Chlorophyll and Accessory Pigments • Euglenophytes • Chrysophytes • Diatoms • Dinoflagellates • Ecology of Unicellular Algae

  4. Ch. 20 Outline • 20-4: Plant-like Protists: Multicellular Algae • Red Algae • Brown Algae • Green Algae • Human Uses of Algae • 20-5: Fungus-like Protists • Ecology of Fungus-like protists

  5. What is a Protist? • Protist: Any eukaryotic organism that is not a plant, animal, or fungus. • Kingdom Protista is the most diverse kingdom. They can be unicellular or multicellular

  6. Classification of Protists • One way to classify protists is by how they obtain nutrition: • Heterotrophs – animal like • Autotrophs – plant like • Decomposers/Parasites – fungus like

  7. Phyla Tree

  8. Zooflagellates • Animal-like protists that swim using a flagella are classified in the Phylum zoomastigma and are often referred to as zooflagellates. • Flagella: Long, whiplike projection that enable movement.

  9. Sarcodines • Sarcodines are animal-like protists that use pseudopods for feeding and movement • Ex. Amoebas • Amoebas capture food by surrounding it, then taking it in and forming a food vacuole. • Food Vacuole: small cavity in the cytoplasm that temporarily stores food.

  10. Amoeba Pseudopods

  11. Ciliates • Members of the phylum Ciliophora, known as ciliates, use cilia for feeding and movement. • Cilia beat like oars • Ex. Paramecium • Anatomy of a Paramecium • Macronucleus: “Working Library” of a genetic information • Micronucleus: contains a “reserve copy” of all the cell’s genes • Gullet: Indentation on one side of the organisms (food enters here) • Anal Pore: Region where waste is emptied • Contractile vacuole: Expels excess water

  12. Paramecium

  13. Sporozoans • Members of the Phylum Sporozoa do not move one their own and are parasitic.

  14. Animal-like Protists and Disease • Protists can causes some diseases. • Example: Malaria • Caused by the sporozoans Plasmodium, which is carried by the Anopheles mosquito • Plasmodium infects liver cells and RBC’s where it reproduces causing those cells to burst

  15. Malaria

  16. Ecology of Animal-like Protists • Recycle nutrients in the environment • Serve as food for larger animals • Live symbiotically with other organisms • Ex. Trichonympha live in the guts of termites and enable them to digest wood (by the enzyme cellulase)

  17. Chlorophyll and Accessory Pigments • Many protists contain the green pigment, chlorophyll and carry out photosynthesis. One the ways plant-like protists are categorized is by the type of photosynthetic pigment they contain. • Accessory pigments: absorb light at different wavelengths than chlorophyll • Review: The energy from sunlight is used by photoautotrophs to make sugars for food

  18. Euglenophytes • These protists have two flagella but no cell wall. • Ex. Euglena • Eyespot: Reddish pigment near the gullet • Senses light • Euglena can also be heterotrophic

  19. Euglena Chloroplast Carbohydrate storage bodies Gullet Pellicle Contractile vacuole Nucleus Flagella Eyespot

  20. Chrysophytes • These protists have gold-colored chloroplasts • Ex. Yellow-green and golden-brown algae

  21. Diatoms • Diatoms produce thin, delicate cell walls rich in Silicon (Si) – the main component in glass. • Used in pesticides – Like Shrapnel!

  22. Dinoflagellates • Many of these are lumniscent. • About half are photosynthetic and half are heterotrophs. • They have two flagella also.

  23. Dinoflagellates

  24. Ecology of Unicellular Algae • Plant-like protists serve as the base of a food chain in many aquatic ecosystems • Phytoplankton: population of small, photosynthetic organisms found nears the surface of the ocean. • Protists make up much of phytoplankton

  25. Agal Blooms • When waste is high the number of plant-like protists increases greatly (since they use the organic matter for food). This is called a bloom • A “red tide” is a bloom of dinoflagellates. They give off a toxin that harms both humans and fish.

  26. Red Algae • Red Algae are able to live at great depths due to their efficiency in harvesting light energy. Red Algae contain chlorophyll a and reddish accessory pigments called phycobilins.

  27. Brown Algae • Brown Algae contains chlorophyll a and c, as well as a brown accessory pigment called fucoxanthin.

  28. Green Algae • Green Algae share many characteristics with plants, including their photosynthetic pigments and cell wall composition. • Pigments: a and b

  29. Human Uses of Algae • Photosynthesis  oxygen in atmosphere • Chemicals in algae used in medicines • Food source • Chemicals used to make plastics, waxes, paints and more!

  30. Fungus-like Protists • Like fungi, funguslife protists obtain their food by digesting outside their bodies (heterotrophs), but they do not have cell walls of chitin like fungi. • Two types of mold: • Slime Molds • Water Molds

  31. Water Mold

  32. Slime Mold MEIOSIS FERTILIZATION Zygote Germinating spore Spores Mature sporangium Feeding plasmodium Young sporangium Mature plasmodium Haploid (N) Diploid (2N)

  33. Ecology of Fungus-like Protists • Important recyclers of organic material • Decomposers of dead things! • Some cause plant diseases • Potato Blight in Ireland caused by water mold • Lead to Irish immigration to America

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