Kingdom Protista

September 12, 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, Plant-like Protists: Algae  all autotrophs  contain chlorophyll  have cell walls  2 major groups a) unicellular algae b)multicellular algae phytoplankton seaweed diatoms brown algae

September 12, Plant-like Protists: Algae a) unicellular algae  very important because: 1. begin every aquatic food chain 2. produce 67% of atmospheric O 2 3. overpopulation causes algal blooms which can cause: i) dead algae decomposed by saprophytes  consume large amounts of O 2 – none left for fish  swamp produced ii) produce toxins which kill fish can also be harmful to humans  ex. red tide

September 12, 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 Volvox

September 12, 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, 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, Animal-like Protists b) flagellates  move with long whip-like flagella  some parasitic pathogens ex. African sleeping sickness trypanosome Giardia lamblia (beaver fever)

September 12, Animal-like Protists c) ciliates  move with cilia (short hair-like projections) that can cover cell ex. paramecium

September 12, 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 anopheles mosquito RBC

September 12, Paramecium Structure cilia contractile vacuole cytoplasm micronucleus macronucleus oral groove gullet food vacuole forming anal pore food vacuole

September 12, Paramecium spiral movement

September 12, Paramecium Reproduction Binary fission (asexual reproduction) Conjugation (sexual reproduction) have two nuclei exchange micronucleus with another paramecium 2 new organisms (genetically identically ) same 2 organisms (genetically different )

September 12, Amoeba Structure nucleus ectoplasm endoplasm contractile vacuole food vacuole pseudopod cytoplasm Note: contractile vacuole collects all the H 2 O that diffuses in by osmosis contracts & pumps H 2 O out to stop amoeba from bursting

September 12, Amoeba Feeding phagocytosis food pseudopod pseudopod surrounds food food enters a food vacuole enzymes break down food in vacuole

September 12, Amoeba Reproduction Binary Fission (asexual) one amoeba divides into 2 identical amoebas