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Kingdom Protista. Chapter 19. General Characteristics of Protists :. ALL Eukaryotes that cannot be classified as a plant, animal, or fungus. They have a nucleus and membrane bound organelles; some are autotrophic, some are heterotrophic; some are multicellular, most are unicellular.
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Kingdom Protista Chapter 19
General Characteristics of Protists: • ALL Eukaryotes that cannot be classified as a plant, animal, or fungus. • They have a nucleus and membrane bound organelles; • some are autotrophic, some are heterotrophic; • some are multicellular, most are unicellular.
Three kinds of protists • Animal-like (consume food) • Plant-like (make their own food) • Fungus-like (decomposer)
KEY CONCEPTAnimal-like protists are single-celled heterotrophs that can move.
Animal-like Protists • Called Protozoans- meaning “first animals” • Examples: • Zooflagellates • Sarcodines • Ciliates • Sporozoans
Protozoans • these are “Animal-like” protists that consume their food (heterotrophs) • Unicellular • characterized by modes of locomotion (how they move) • Cilia • Flagella • Pseudopod
Zooflagellates Trichomonas • Characteristics: move by flagella (one or two) • Reproduction: mostly asexual by mitosis, some sexual reproduction- produce gametes that fuse • Role/Function: • Mostly free swimming • Some are parasites • Trypanosoma causes African Sleeping Sickness, Giardia causes diarrhea • Termites have a zooflagellate living inside them that helps them digest wood
Zooflagellates nucleus flagella
Sarcodines • Characteristics: move by pseudopods- extensions of cytoplasm • Reproduction: asexually by mitosis • Role/Function: • free-swimming in aquatic environments • Amebic dysentery (diarrhea) Pseudopod Nucleus Ameba proteus
Ciliates • Characteristics: • use cilia for movement and feeding • Have a macronucleus (active nucleus) and micronucleus (reserve copy) • Reproduction: asexually by mitosis, can exchange material through conjugation (Figure 20-6 in book) • Role/Function: free-living Paramecium
Ciliates Macronucleus Cilia Micronucleus
Sporozoans • Characteristics: Do not move on their own • Reproduction: complex reproduction with two phases- a sexual phase and asexual phase inside two different organisms! • Role/Function: • Parasitic • Malaria is caused by the sporozoan Plasmodium
Sporozoans Nucleus
Unicellular Euglenophyta Chrysophyta Bacilliarophyta (Diatoms) Pyrrophyta (Dinoflagellates) Plant-like (Algae) • Multicellular • Rhodophyta • Phaeophyta • Chlorophyta
Unicellular Algae • (describe their ecology/uses): • autotrophic, capture sunlight with chlorophyll and other accessory pigments to make food • base of many aquatic food chains • Example: phytoplankton- floating photosynthetic organisms
Euglenophyta • Characteristics: two flagella, no cell wall • Reproduction: asexually by mitosis • Role/Function: • free-swimming • can absorb material for food- recycling sewage • can lead to algal blooms choking waters of nutrients
pellicle contractile vacuole nucleus flagellum chloroplast eye spot • mostly photosynthetic • some heterotrophic • single-celled • one or two flagella • Euglenoids are a large group of plantlike protists.
Euglenophyta Chloroplast Flagellum Nucleus
Chrysophyta • Characteristics: • cell walls sometimes of pectin • Gold-colored chloroplasts • Reproduction: asexually and sexually • Role/Function: free-floating • Known as “golden algae”
Diatoms • Characteristics: secrete thin cell walls of silica (main component of glass) • Reproduction: asexually and sexually • Role/Function: • Free-floating, or • live in soil
Diatoms are plantlike protists with glasslike shells. • shells made of silica • produce large amounts of oxygen
Pyrrophyta-Dinoflagellates • Characteristics: have two flagella and thick cell wall • Reproduction: asexually by mitosis • Role/Function: responsible for red tides (algal bloom of dinoflagellates that secrete toxins that can cause illness paralysis, and death in fishand humans)
have two flagella • may be bioluminescent • have stiff protective plates • can cause red tide • Dinoflagellates are mostly marine plantlike protists. Dinoflagellates
Dinoflagellates Nucleus Flagella
Green algae contain chlorophyll a and b. • Brown algae contain chlorophyll c. • Multicellular algae are classified by their pigments. • Red algae contain chlorophyll a and phycoerythrin.
Multicellular Algae • (describe their ecology/uses)- • Autotrophic • Multicellular • some have specialized tissue • seaweeds and kelp • used in foods such as sushi, ice cream, salad dressing, candy, etc.
Red Algae (Rhodophyta) • Characteristics: contain pigments- Chlorophyll a and Phycobilins (red) • Reproduction: sexually • Role/Function: • Deeper sea, great at harvesting light • Help form coral reefs • Some used in foods and to make agar
Brown algae (Phaeophyta) • Characteristics: contain pigments Chlorophyll a and c and Fucoxanthin (brown) • Reproduction: sexually by mitosis and meiosis • Role/Function: • Form large habitats in aquatic ecosystems • Used some in food
Volvox- colonial Green algae (Chlorophyta) • Characteristics: • unicellular, colonial, or multicellular • chlorophyll a and b • Reproduction: sexually by mitosis and meiosis like true plants • Role/Function: some form symbiotic relationships with other organisms Ulva- multicellular Spirogyra- multicellular
Some species alternate generations. • Some algae produce sexually. • Sexual reproduction can be triggered by environmental stress.
Fungus-like • Slime Molds • Water Molds
Slime molds and water molds are funguslike protists. • Slime molds have both funguslike and animallike traits. • decomposers, like fungi • can move, like animals
Fungus-like • (describe their ecology/uses): • heterotrophic using external digestion to break down dead and decaying organic matter
Slime Molds • Characteristics: • cellular or acellular (masses with several nuclei) • Unicellular but can gather and act multicellular • Reproduction: sexually • Role/Function: Forest floor or composting- recycle organic matter
Slime molds can be plasmodial or cellular. • Plasmodial slime molds are giant cells with many nuclei. • Cellular slime molds contain independent cells.
Water Mold • Characteristics: • also called oomycetes (O-O-my-sets) • Produce filaments called hyphae • Reproduction: sexually and asexually • Role/Function: • dead decaying matter in aquatic environments • some are plant parasites • attack tomatoes and potatoes
Water molds are freshwater, funguslike protists. • one type of water mold caused Great Potato Famine of Ireland in the 1800’s • made of branching strands of cells • can be parasites of plants or fish