Transcript Protists
Kingdom Protista Protists most diverse kingdom all eukaryotic mostly unicellular aquatic organisms asexual reproduction generally by binary fission 3 different groups 1. plant-like 2. animal-like 3. fungi-like September 12, 2012 2 1. Plant-like Protists: Algae all autotrophs contain chlorophyll have cell walls 2 major groups a) unicellular algae phytoplankton b)multicellular algae seaweed diatoms brown algae September 12, 2012 3 Plant-like Protists: Algae a) unicellular algae very important because: begin every aquatic food chain 2. produce 67% of atmospheric O2 3. overpopulation causes algal blooms which can cause: i) dead algae decomposed by saprophytes consume large amounts of O2 – none left for fish swamp produced ii) produce toxins which kill fish can also be harmful to humans ex. red tide 1. September 12, 2012 4 Plant-like Protists:Seaweed b) multicellular algae (seaweed) no real tissues i.e. colonies food source for fish and humans cell walls of red algae used to make: i. agar ii. gel caps iii. cosmetics September 12, 2012 Volvox 5 2.Fungus-like Protists (Slime Moulds) multicellular body (like giant amoeba) called a plasmodium roll over forest floor feeding on dead organic matter move very slowly (few mm/day) reproduce asexually with spores (like fungi) in fruiting bodies September 12, 2012 6 3. Animal-like Protists all heterotrophs classified by how they move a) pseudopods: move with cytoplasmic projections called pseudopods (false feet) ex. amoeba • some pathogenic •i.e. amoebic dysentery September 12, 2012 7 Animal-like Protists b) flagellates move with long whip-like flagella some parasitic pathogens ex. African sleeping sickness Giardia lamblia (beaver fever) trypanosome September 12, 2012 8 Animal-like Protists c) ciliates move with cilia (short hair-like projections) that can cover cell ex. paramecium September 12, 2012 9 Animal-like Protists d) sporozoa reproduce by asexually by spores have no means of locomotion many parasites, which depend on host body fluids to move ex. Malaria RBC anopheles mosquito September 12, 2012 10 Paramecium Structure cilia contractile vacuole cytoplasm micronucleus macronucleus oral groove gullet food vacuole forming anal pore food vacuole September 12, 2012 11 Paramecium spiral movement September 12, 2012 12 Paramecium Reproduction Binary fission (asexual reproduction) same 2 organisms (genetically different ) Conjugation • • (sexual reproduction) have two nuclei exchange micronucleus with another paramecium 2 new organisms (genetically identically ) September 12, 2012 13 Amoeba Structure contractile vacuole endoplasm food vacuole pseudopod ectoplasm nucleus Note: contractile vacuole cytoplasm •collects all the H2O that diffuses in by osmosis •contracts & pumps H2O out to stop amoeba from bursting September 12, 2012 14 Amoeba Feeding phagocytosis pseudopod food September 12, 2012 pseudopod surrounds food food enters a food vacuole enzymes break down food in vacuole 15 Amoeba Reproduction Binary Fission (asexual) one amoeba divides into 2 identical amoebas September 12, 2012 16