protists chapter 20. any organism that is not a plant, animal, fungus, or bacteria. all eukaryotes...
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ProtistsProtistsChapter 20
Any organism that is not a plant, animal, fungus, or bacteria.
All EukaryotesMost are unicellular; a few
multicellularClassify according to method of
nutrition◦Animal-like – heterotrophs◦Plant-like – photoautotrophs◦Fungus-like – decomposers
Protozoans – animal-likeProtozoans – animal-likeGrouped by how they moveZooflagellates
◦ Swim w/ flagella (most have 1 or 2)◦ Absorb nutrients through cell membrane
Sarcodines ◦ Use pseudopodia (cytoplasmic extensions) to
move and feed – aka amoeboid movement◦ Feed by surrounding food w/
pseudopodia and forming a food vacuole around it
◦ Ex. Amoebas, heliozoans◦ Ex. Foraminiferans – have shells of
calcium carbonate – White Cliffs of Dover, England
Protozoans cont.Protozoans cont.
Ciliates◦Use cilia (hairlike projections) to move◦Ex. Paramecium – has a macronucleus
(uses every day) and a micronucleus (a reserve copy of all the genes)
Sporozoans◦Parasites - Do not move on their own◦Complex life cycles w/ more than one
host
Protozoans cont.Protozoans cont.Diseases
◦Malaria – caused by sporozoan Plasmodium Carried by female Anopheles mosquito In human – infects liver cells where it moves to
red blood cells – causes rbcs to burst = chills and fever
◦African sleeping sickness – caused by zooflagellate Trypanosoma Carried by tsetse fly Infects nerve cells = unconsciousness
◦Amebic dysentery – caused by sarcodine Entamoeba – Invade intestines
Protozoans cont.Protozoans cont.Ecological importance
◦Break down organic matter, provide food for small aquatic animals
◦Trichonympha – lives in guts of termites Breaks down cellulose in wood for termite to digest
Algae – plant-likeAlgae – plant-likeGrouped by type of
photosynthetic pigmentsAre found in phytoplankton –
carry out ½ of the photosynthesis on Earth & provide nourishment for many ocean creatures
Euglenophytes – unicellular ◦2 flagella◦Heterotrophic if no sun
Algae cont.Algae cont.Chrysophytes – unicellular
◦Gold-colored chloroplasts◦Ex. Yellow-green algae,
golden-brown algaeDiatoms – unicellular
◦Box-like shells of silicaDinoflagellates – unicellular
◦2 flagella◦Autotrophs and heterotrophs◦Bioluminescent◦Release toxins – produce red
tide
Algae cont.Algae cont.Red algae – multicellular
◦Contain phycobilins (absorb blue light) which allow them to live at great depths
Brown algae – multicellular ◦Contain fucoxanthin – brown pigment ◦Largest◦Ex. kelp
Algae cont.Algae cont.Green algae
◦uni/multicellular; some colonial◦Cell walls of cellulose◦Fresh/salt water◦Ex. Ulva (sea lettuce), volvox
Uses◦Treat stomach ulcers, arthritis◦Food – wrap sushi, ice cream, pudding,
salad dressing, eggnog, pancake syrup◦Industry – paints, plastics, transistors
Fungus-like protistsFungus-like protistsSimilar to fungi – are decomposersDifferent from fungi – lack chitin cell
wallsSlime molds
◦Like damp places rich with organic matter
◦Cellular slime molds Have distinct cell membranes
◦Plasmodial slime molds No cell membranes Form a plasmodium with many
nuclei
Fungus-like cont.Fungus-like cont.Water molds
◦Live on dead material in water or as plant parasites
Ecological effects◦Decomposers◦Mildews and blights on plants◦Ex. Phytophthora infestans – caused
the Irish potato famine
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