1. Unit 6--Microbiology Chapter 20 Protists

2. Endosymbiotic theory Heterotrophic bacteria have plasmids (DNA loop) & simple ribosomes in their cytoplasm Mitochondria have circular DNA & bacteria-like ribosomes So…Eukaryotic cells may have engulfed prokaryotic cells & by mutualism created the “first mitochondria.”

3. Autotrophic bacteria are Cyanobacteria with chlorophyll So, Eukaryotic cells may have engulfed prokaryotic cyanobacteria & by mutualism created the “first chloroplast.”

5. Characteristics Mostly unicellular Eukaryotic cells Most diverse kingdom: –Photosynthesis, like plants (algae) –Ingest food, like animals (protozoans) –Absorb food, like fungus (slime mold)

6. Classifying protists DNA evidence shows that some archaebacteria may have been ancestors of protists.

7. Phylum…example… distinguishing characteristics Zoomastigina… Trypanosome Causes Sleeping sickness All are flagellated Other examples include those living symbiotically within termite intestine

8. Phylum…example… distinguishing characteristics Rhizopoda…ameba Moves by pseudopods = cytoplasmic extensions Feed by phagocytosis = surrounding & engulfing

9. Phylum…example… distinguishing characteristics Foraminifera… Forams Ameba-like body within a shell-like test Often build-up accumulates after many years

10. Electron microphotograph of Radiolarian, a marine Protist

11. Phylum…example… distinguishing characteristics Ciliophora … paramecium All are ciliated Macro & micronuclei Oral groove & gullet bring food into vacuole Contractile vacuole pumps out water

12. See page 501

13. Phylum…example… distinguishing characteristics Sporozoa… Plasmodium Causes Malaria Carried by female Anopheles mosquito During bite: insect saliva inserted or infected blood ingested by insect

14. See page 503

15. Plasmodium attacking red blood cells and rupturing RBC

16. Phylum…example… distinguishing characteristics Euglenophyta… Euglena Animal-like flagella, eyespot, and reservoir (to ingest) Plant-like chloroplasts for photosynthesis

17. Euglena structures Pellicle – EM image

18. See page 507

19. Phylum…example… distinguishing characteristics Bacillariophyta… Diatoms Unicellular marine algae; main producer in the sea Glass-like cell walls of silica Unique shapes

21. Phylum…example… distinguishing characteristics Dinoflagellata… dinoflagellates Unicellular algae; 2 nd only to diatoms as main producer Often has flagella, plates, spikes, and other projections Causes “red tide”

22. Bioluminescence

23. Phylum…example… distinguishing characteristics Rhodophyta…red algae Small, multicellular algae May be an epiphyte on larger algae Used to make agar

24. Phylum…example… distinguishing characteristics Phaeophyta… brown algae Largest, multicellular algae Includes Kelp, which may grow 100 ft Plant-like body with holdfasts, stalks and blades, & air bladders for support

25. Sargasso Sea Sargassum Many square kilometers of the open Atlantic Ocean between the islands of the Azores and the Bahamas are covered by huge, floating algae called Sargassum. Known as the Sargasso Sea, this area of warm water is named for the brown algae that dominate its surface.

26. Uses of red and brown algae Carrageenan Agar Seaweed

27. Phylum…example… distinguishing characteristics Chlorophyta… green algae Ancestors of plants In all environments, even on land Unicellular to multicellular (sea lettuce) Ex: Volvox and Spirogyra

29. Conjugation in Paramecium

30. Phylum…example… distinguishing characteristics Myxomycota… plasmodial slime mold A mass of cytoplasm containing many nuclei Uses spores to survive harsh conditions

31. Acellular slime mold plasmodium

32. Cellular slime mold