PROTISTS: THE UNICELLULAR EUKARYOTES

PROTISTS Eukaryotic Usually unicellular Diversely shaped Not a fungus, plant or animal Three types: - Animal-like - Fungus-like - Plant-like ** Refer to the table on page 72 **

ANIMAL-LIKE PROTISTS Also known as Protozoans Heterotrophs Some are parasitic

ANIMAL-LIKE PROTISTS THE CERCOZOANS: PHYLUM CERCOZOA Ex: Amoebas -Cell membrane without a cell wall: change shape using their cytoskeleton -Pseudopods: temporary extensions of cytoplasm (false feet), used for feeding and locomotion -Live in salt water, fresh water and mud; few are parasites in an animal

ANIMAL-LIKE PROTISTS THE CERCOZOANS: PHYLUM CERCOZOA Ex: Amoebas -Ex: Entamoeba hystolitica -Feeds on lining of small intestine causing amoebic dysentery -Spread by contaminated water or produce

ANIMAL-LIKE PROTISTS THE CILIATES: PHYLUM CILIOPHORA Ex: Paramecia -Large and complex -Have many cilia covering their surface for locomotion and sweeping food into themselves -Free-living; other types are parasites

ANIMAL-LIKE PROTISTS THE CILIATES: PHYLUM CILIOPHORA Ex: Paramecia -Ex: Balantidium coli -Lives in large intestine and causes diarrhea

ANIMAL-LIKE PROTISTS THE FLAGELLATES: PHYLUM ZOOMASTIGINA Ex: Flagellates -Have one or more flagella with protective coverings -Some are free-living, some are parasites, some are in mutualistic relationships

ANIMAL-LIKE PROTISTS THE FLAGELLATES: PHYLUM ZOOMASTIGINA Ex: Flagellates -Ex: Flagellates living in termite intestines -Convert cellulose to sugar in return for food and habitat

ANIMAL-LIKE PROTISTS THE SPOROZOANS: PHYLUM SPOROZOA Ex: Sporozoans -Parasites of animals -Most with alternating sexual and asexual reproduction, even alterning between two hosts

ANIMAL-LIKE PROTISTS THE SPOROZOANS: PHYLUM SPOROZOA Ex: Sporozoans - Ex: Plasmodium - Cause malaria in humans

FUNGUS-LIKE PROTISTS Heterotrophs Absorb nutrients from living organisms, dead organisms, and wastes Produce spores Different from fungi at the cellular level

FUNGUS-LIKE PROTISTS PLASMODIAL SLIME MOULDS: PHYLUM MYXOMYCOTA Ex: Plasmodium -Many nuclei -Tiny slug-like organisms -Creep over damp, decaying plant material in forests and fields -Engulf small particles of food into their cytoplasm -Part of cytoplasm is concentrated to form a skeleton-like structure

FUNGUS-LIKE PROTISTS CELLULAR SLIME MOULDS: PHYLUM ACRASIOMYCOTA -Individual amoeboid cells with one nucleus each -Feeds by ingesting tiny bacteria or yeast -Can also feed by releasing a chemical that causes them to gather together to form a pseudoplasmodium (only when food is scarce)

FUNGUS-LIKE PROTISTS WATER MOULDS: PHYLUM OOMYCOTA -Filamentous (resembles fungi) -Can extend fungus-like threads into their host’s tissues where they release digestive enzymes and absorb resulting nutrients -Live on dead organic matter -Some are parasites on fish, insects, and plants

PLANT-LIKE PROTISTS Contain pigments in their chloroplasts (Ex: chlorophyll) to carry out photosynthesis

PLANT-LIKE PROTISTS DIATOMS: PHYLUM CHRYSOPHYTA Ex: Diatoms (type of phytoplankton) -Single celled aquatic organisms -Free floating -Rigid cell walls with an outer layer of silica -Two unequal parts to cell wall -Reproduce asexually by mitosis or sexually when conditions are unfavourable -Important food source for larger marine organisms

PLANT-LIKE PROTISTS DINOFLAGELLATES: PHYLUM PYRROPHYTA -Type of phytoplankton -2 flagella at right angles to one another -Flagella allow organisms to spin -Reproduce quickly (causing an algal bloom) -Some living inside other organisms

PLANT-LIKE PROTISTS DINOFLAGELLATES: PHYLUM PYRROPHYTA -Ex: Red Tide -Dinoflagellates with red photosynthetic pigments -Red bloom -Produce a toxin that can accumulate in plankton-eating-shellfish which can be fatal to humans

PLANT-LIKE PROTISTS DINOFLAGELLATES: PHYLUM PYRROPHYTA -Ex: Symbiodinium -Reef building corals -Use nitrogen and carbon dioxide from corals in return for photosynthetic products -In high termperatures: coral bleaching occurs which breaks the coral-protist partnership

PLANT-LIKE PROTISTS EUGLENOIDS Ex: Euglena -Found in shallow fresh water -Have chloroplasts which allow for photosynthesis (in sunlight) -Have flagella and can absorb nutrients (in darkness) -Have an eyespot for light detection