Kingdom Protista (Protists) pp. 128 to 133

What are Protists? Characteristics: –Eukaryotic (nucleus) –Most are unicellular (few are multicellular) –Most reproduce asexually (binary fission); some reproduce sexually (exchange of DNA) –Thrive in moist or damp environments Three groups: 1.Protozoa (animal-like) 2.Algae (plant-like) 3.Moulds (fungi-like)

Protozoa (Animal-like) Unicellular and microscopic Heterotrophs  Usually feed on bacteria, some feed on dead matter Lack cell walls Must move to obtain food  classification based on type of locomotion

1.Ciliates Cilia (hairlike) Swimming, surface attachment, sweeping food into food cavity Paramecium – cilia sweeps food into oral groove that leads to gullet (stomach). Food moves to food vacuole where digestion takes place. Wastes are rid through anal pore and water through contractile vacuole. Defense mechanism – similar to poison barbs Control reproduction Control cell activities

2.Flagellates Flagella Propulsion or food gathering Trypanosoma – tsetse fly (sleeping sickness) 3. Sarcodines Extension of cell membrane/cytoplasm to form pseudopod (“false foot”) Amoeba Feed by phagocytosis (pseusopod wraps around food to make food vacuole. Water diffuses along membrane and collected by contractile vacuole.

4.Sporozoans Non-mobile Forms spores  can develop into an individual without fertilization Parasitic (depend on host for movement) Plasmodium – causes malaria. Mosquito infected with disease releases spores into human RBC when bitten. Spores then reproduce asexually. When another mosquito bites infected human, it picks up the disease and passes it on. Life cycle on p. 131

Algae (Plant-like) Aquatic and contain chlorophyll (autotrophs) Can switch to heterotroph if not enough light Not true plants (do not have roots, stems and leaves) 6 sub-groups (4 will be covered briefly)

1. Euglenoids Unicellular Euglena has stigma eyespot (sensory) and flagellum (to propel) Chloroplasts help make food and food stored in vacuoles In harsh conditions, cell thickens up to protect contents

Algae  multicellular (except green, which is unicellular) and highly adaptable –Makes 80% of global O 2 (imp. to aquatic systems) –Great source of vitamins and minerals 2. Green Algae Primary food producers in aquatic systems Marine (salt) and freshwater 3. Brown Algae “seaweed”  marine waters Decomposition of B.A.  crude oil for us 4. Red Algae “seaweed”  marine waters Material for drug capsules, gels, makeup

Moulds (Fungi-like) Cool, shady, moist places: in water, fallen leaves and rotting logs Heterotrophs Produce spores and may have flagella/pseudopods at some stage Eg. Irish potato famine (potato blight disease)