1. Introduction to Protists

2. First eukaryotic organism thought to have evolved about 1.5 billion years ago Endosymbiosis – process where one prokaryote lives inside another becoming dependent upon each other Origin of Eukaryotes

3. Infolding of membrane system forming nucleus and ER Origin of Eukaryotes Endomembrane infolding

4. Origin of Eukaryotes Evolution of eukaryotic cell- Endosymbiosis – a theory Mitochondria and plastids were prokaryotes that invaded larger cells Relationship began as parasitic or undigested prey

5. Endosymbiosis Hypothesis A A prokaryote ingested some aerobic bacteria. The aerobes were protected and produced energy for the prokaryote Chloroplasts Aerobic bacteria Mitochondria Cyanobacteria Prokaryote Animal Cell Plant cell B C D A N N N N

6. Endosymbiosis Hypothesis B Over a long period of time the aerobes became mitochondria, no longer able to live on their own A B C D Chloroplasts Aerobic bacteria Mitochondria Cyanobacteria Prokaryote Animal Cell Plant cell N N N N

7. Endosymbiosis Hypothesis C Some primitive prokaryotes also ingested cyanobacteria, which contain photosynthetic pigments A B C D Chloroplasts Aerobic bacteria Mitochondria Cyanobacteria Prokaryote Animal Cell Plant cell N N N N

8. Endosymbiosis Hypothesis D Cyanobacteria became chloroplasts, unable to live on their own A B C D Chloroplasts Aerobic bacteria Mitochondria Cyanobacteria Prokaryote Animal Cell Plant cell N N N N

9. LUCA model places the archaea as more closely related to eukaryotes than they are to prokaryotes.

10. Kingdom Protista Plantae Fungi Animalia Protista Eubacteria & Archaea prokaryotic eukaryotic

11. Kingdom Protista Eukaryotic Mostly unicellular but some multicellular A very heterogeneous group include both heterotrophic and autotrophic forms

12. binary fission splits into two asexually sexually by conjugation (opposite mating strains join & exchange genetic material) Sexually by producing gametes (meiosis) Reproduction:

13. 3 informal groups Animal-like protists Fungus-like protists Plant-like (algal) protists Kingdom Protista ~ 45,000 species

14. Amoeba (phylum Cercozoa) Cilliates (phylum Ciliophora) Flagellates (phylum Zoomastigina) Sporozoans (phylum Sporozoa) Animal-like Protists 13,000 species

15. Classified by the way they move Animal-like Protists cilia flagella pseudopodia

16. Heterotrophs ingest small food particles & digest it inside food vacuoles containing digestive enzymes

17. Phylum Cercozoa “Amoeba” Have pseudopods for feeding and movement Animal-like Protists

18. Foramenifera: Globigerina ooze Covers about 36% of the ocean floor

19. Phylum Ciliophora (“ciliates”) Largest, most homogeneous Share few characteristics with others Movement coordinated Animal-like Protists 8,000 species

20. Paramecium

22. Asexual reproduction Binary fission

23. Paramecium reproduction 1. Individuals fuse 2. Micronucleus produces 4 haploid nuclei

24. Phylum Zoomastigina (“zooflagellates”) Move using flagella Move using flagella:1 to thousands of flagella Some parasites African trypanosomiasis – sleeping sickness – tsetse flyAfrican trypanosomiasis – sleeping sickness – tsetse fly Chagas Disease – kissing bugChagas Disease – kissing bug Leishmaniasis – sand flyLeishmaniasis – sand fly giardiasisgiardiasis Animal-like Protists 1,500 species

25. African sleeping sickness Tsetse fly Trypansoma

26. The Kissing Bug Chagas disease

27. Leishmaniasis Sand fly Leishmania

28. Malaria Mosquito & “victim” Africa = kills 1 million children per year Thousands of sporozoites injected Vaccine? (US support?) Anopheles Mosquito Plasmodium sporozoite gameteocyte

29. The Sporozoans: Phylum Sporozoa Parasites of animals Alternate between sexual & asexual production

30. Plasmodium, the parasite that causes malaria, spends part of its life in mosquitoes and part in humans.

31. Fungus-like Protists Phylum Oomycota (“water molds”; mildew, blights) Some unicellular; others consist of hyphae Decomposers,parasites Cell walls- cellulose Related to algae based on cell wall composition Named after reproductive method 475 species No “septa”

32. water molds

33. Downy Mildew

34. Mildew hyphae

35. Oomycota Reproduction: the “egg fungi”, a relatively large egg cell is fertilized by a smaller “sperm nucleus,” forming a resistant zygote.

36. Fungus-like Protists Phylum Myxomycota (“slime molds”) Bizarre Bright colors Moving “slime” mass 550 species

37. Fungus-like Protists Phylum Acrasiomycota Resemble amoebas Ingest bacteria and yeast Known as cellular slime moulds

40. Plant-like Protists Dinoflagellates Diatoms Euglena Cocolithophore Green algae Brown Algae Red algae Diatoms Dinoflagellates Radiolarian Cocolithophore

41. Plant-like Protists Phylum Pyrrophyta (“dinoflagellates”) 1,100 species Cause “red tide” Some live in corals Marine and Freshwater

42. Zooxanthellae in Coral Polyp

43. Pyrocystis fusiformis Bioluminescence

44. HAB (harmful algal blooms) can result in PSP (paraletic shellfish poisoning) Gonyaulax polyhedra, Gymnodium

46. The numbers are representative values of the concentration in the tissues of dinoflagellate toxin (ppm) Primary producers Primary consumers Secondary consumers Tertiary consumers 0.04 ppm 0.23 ppm 2.07 ppm 13.8 ppm

47. Plant-like Protists Phylum Chrysophyta - diatoms 13,000 species

48. epithecate hypothecate Diatom Reproduction- asexual auxospore Discards shell and grows new one

49. Phylum Euglenophyta (“euglenoids”) Plant-like Protists 800 species

50. Division Chlorophyta “Green algae” Most freshwater or terrestrial Some marine 7,000 species

51. Halimeda opuntia Chlorophyta: Green Algae Caulerpa racemosa Caulerpa sertularioides Dictyosphaeria cavernosa Codium edule

52. Division Phaeophyta “Brown algae” Marine habitats Example: giant kelp forests 1,500 species

53. Example of complex morphology: Macrocystis a.holdfast - attaches to substrate b.stipe c.blade - main organ of photosynthesis d.bladder - keeps blades near the surface Blade Bladder Stipe Holdfast

54. Laminaria Life Cycle

57. Sargassum polyphyllum Sargassum echinocarpum Phaeophyta: Brown Algae Turbinaria ornata Padina japonica Hydroclathrus clathratus

58. Division Rhodophyta “Red algae” Most in marine habitats 4,000 species

59. Hypnea chordacea Asparagopsi s taxiformis Galaxaura fastigiata Acanthophora spicifera Ahnfeltia concinna Rhodophyta: Red Algae