1. Protists

2. Characteristics Most diverse kingdom eukaryotic., 1.5 bya Primarily unicellular/multicellular, heterotrophic/autotrophic Usually asexual, some sexual Found in water, damp soil and sand, leaf litter Some are parasitic 14 phyla

3. Characteristics Characteristics first seen in Protista kingdom Sexual reproduction (varies, mitosis and meiosis – usually in harsh enviro.) Multicellularity (coordination among specialized cells) Complex flagella and cilia (as opposed to simple seen in bacteria)

4. Protist diversity Heterotrophic protists = protozoans, slime molds, parasites Photosynthetic protists = Algae Some are classified further by how they move: Amoebas – pseudopodia Ciliates – cilia, ex. paramecium Flagellates – flagella, ex. Euglena

5. Amoeba Pseudopodia – false foot, cytoplamsic extensions Food vacuole – food enters and moves throughout cell Contractile vacuole – regulates water

6. Diatoms Photosynthetic Double shell made out of silica Move by excreting chemicals through holes in shell Found in oceans and lakes Important to food chain Diatomaceous earth – abrasives

7. Algae – Green, Red and Brown Strict autotrophs, some multicellular Distinguished by type of pigment they contain Red Multicellular, warm ocean waters Red pigment can absorb light in deep water Brown Multicellular, marine Kelp, grows along coasts, food and shelter Green Most freshwater, uni and multicellular Contains chlorophyll a and b

9. Dinoflagellates 2 flagella Unicellular Most are marine, make up part of the plankton Some produce powerful toxins – “red tide”

10. Euglena Fresh water with 2 flagella Some photosynthetic with chloroplasts Pellicle – protein fiber inside cell membrane, allows for flexibility and shape change Eyespot – light sensitive organ, toward light

11. Paramecium Freshwater streams and ponds Unicellular, heterotrophic Cilia to move Two nucluei Macro – cell activities, includes DNA Micro –cell reproduction, contains chromosomes

12. Protistan slime molds Cellular slime mold Behave like amoebas Ingest bacteria During stress, form multicellular colonies Plasmodial slime molds Mass of cytoplasm that looks like ooze Eat bacteria and other organic material

13. Sporozoans – parasitic protists Form spores during their reproductive cycle Nonmotile, unicellular parasites Ex. Malaria, caused by Plasmodium parasite Life cycle page 616, figure 21-14

14. Beneficial protists Commensal protists that live in digestive tracts of humans and livestock (hay, cellulose) Plankton – food, shelter, producers Largest group of photosynthesizers Abrasives Detritivores – recycle chemicals in environment Symbiotic relationships - coral