1. Eukaryotes Protista

2. What do Eukaryotes have that Prokaryotes do not?  Membrane-bound nucleus  Mitochondria, chloroplasts, and endomembrane system  Cytoskeleton  Flagella of microtubule construction  Multiple chromosomes of linear DNA compactly arranged with proteins  Diploid life stages  Mitosis and Meiosis and Sex

3. Compartmentalization of functions occurs in eukaryotes

4. Endosymbiotic theory of eukaryotic evolution  Evidence of mitochondria and chloroplast origin –Appropriate size –Replication by binary fission –Inner membranes containing enzymes and transport systems similar to prokaryotic plasma membranes –DNA is circular and not complexed with histones –Have their own ribosomes, tRNAs and other components for transcription/translation –Ribosomes are more similar to prok. than euk.

5. A model of the origin of eukaryotes A model of the origin of eukaryotes

6. Protistan taxonomy is in a state of flux (a mess) Your Lab book and your text book approach protists in very different manners using different terminology. Your lab book is the more “classic” approach and we will follow that more closely

7. Traditional hypothesis for how the three domains of life are related Traditional hypothesis for how the three domains of life are related

8. An alternative hypothesis for how the three domains of life are related An alternative hypothesis for how the three domains of life are related

9. A tentative phylogeny of eukaryotes (Campbell 6 th Edition) A tentative phylogeny of eukaryotes (Campbell 6 th Edition) We are going to look at protists using a more ‘Classic”, simpler scheme

10. First a couple definitions  Plankton –Communities of organisms, mostly microscopic, that drift passively or swim weakly near the surface of oceans, ponds, and lakes  Encystment –Cyst formation –A response to adverse conditions –Allows a parasitic species to survive outside a host, allows others to survive hostile environmental conditions –Only some protists can do this

11. Archezoans  Lack mitochondria or chloroplasts  Have prokaryotic-like ribosomes  Simple cytoskeletons

12. Archezoans Giardia lamblia Unicellular flagellate. Most commonly transmitted in the cyst form through water contaminated with human feces

13. Trichomonas vaginalis An inhabitant of vaginal tract of human females. Can be sexually transmitted. Has flagella and an undulating membrane for movement

14. The Protozoa (animal-like protists)  Diverse group of heterotrophic protists  Classically grouped into different Phyla based upon their movement and how they feed

15. The Protozoa Rhizopoda – the amoebas  Very simple protists, unicellular  Pseudopodia  Entamoeba histolytica –( human pathogen)

16. Amoeba proteus

17. Use of pseudopodia for feeding Use of pseudopodia for feeding

18. The Protozoa Actinopoda – (Helizoans and Radiozoans)  Axopodia = projections reinforced by bundles of microtubules thinly covered by cytoplasm  Most are planktonic  Heliozoans – fresh water  Radiozoans- marine, silica shells

19. Actinopods: Heliozoan (left), radiolarian (right)

20. Radiolarian skeleton

21. The Protozoa Foraminifera (Forams)  Marine organisms  Porous shells of organic material hardened by calcium carbonate  Many have algae living beneath the shell which provide nutrients via photosynthesis

22. Foraminiferan Foraminiferan

23. The Protozoa Apicomplexa (Sporozoans)  All species are obligate intracellular parasites of animals  Toxoplasma gondii –Toxoplasmosis  Cryptosporidium –Diarrhea. Transmitted via fecal contamination –Water supply outbreaks have been reported  Plasmodium –Malaria

24. The two-host life history of Plasmodium, the apicomplexan that causes malaria

25. The Protozoa Zoomastigophora (flagellates)  Move by whip-like flagella  Trichonympha –Inhabits the gut of termites  Trypanosoma –Hemoflagellate –African Sleeping sickness

26. Trichonympha Trichonympha

27. Trypanosoma, the kinetoplastid that causes sleeping sickness Trypanosoma, the kinetoplastid that causes sleeping sickness

28. The Protozoa Ciliophora (ciliates)  Move by cilia  Most are free-living in fresh water  Paramecium  Stentor  Vorticella Vorticella StentorParamecium

29. Ciliates: Paramecium Ciliates: Paramecium

30. Fungus-like Protists  Filamentous body structure at times makes them appear to be like molds, but they are more closely related to amoebas than to true fungi.  Myxomycota (plasmodial slime molds)  Acrasiomycota (cellular slime molds)  Oomycota (water molds, white rusts, downy mildews)

31. The life cycle of a plasmodial slime mold, such as Physarum The life cycle of a plasmodial slime mold, such as Physarum

32. Plasmodial slime mold Plasmodial slime mold

33. Slime mold Sporangia Slime mold Sporangia

34. The life cycle of a cellular slime mold (Dictyostelium) The life cycle of a cellular slime mold (Dictyostelium)

35. Dictyostelium life cycle Dictyostelium life cycle

36. Stages of Dictyostelium

37. The life cycle of a water mold (Layer 3) The life cycle of a water mold (Layer 3)

38. Water mold: Oogonium Water mold: Oogonium

39. Powdery mildew Powdery mildew

40. Algae  Diverse group of photoautotrophic aquatic organisms  Major role in aquatic food chains  Fix carbon dioxide into organ carbon  Produce somewhere between 50% and 80 % of the Earth’s oxygen

41. Algae Dinoflagellata (dinoflagellates) –They have two flagella and may have armor (cellulose plates) or may be naked (without armor). Dinoflagellates have pigments and can carry on photosynthesis. Major component of phytoplankton. –Gonyaulax  Red tide  Paralytic shellfish poisoning –Peridinium (lab) –Noctiluca miliaris  Bioluminescent

42. Dinoflagellate Dinoflagellate

43. Dinoflagellates

44. Swimming with bioluminescent dinoflagellates

45. Algae Bacillariophyta (Diatoms)

46. a diatom, a unicellular "alga"

47. Chrysophyta Golden algae

48. Phaeophyta (Brown algae)  Largest and most complex of the algae  Kelp is a brown algae –Giant kelp - up to 100 meters in size  Seaweeds = large, multicellular marine algae of coastal waters which include members of the Brown, Red, and Green algae groups

49. Australian bull kelp (Durvillea potatorum)

50. Kelp forest

52. Red algae: Dulse (top), Bonnemaisonia hamifera (bottom) Rhodophyta Red Algae

53. Chlorophyta (green algae)  Over 7000 species known –Freshwater and marine –Unicellular and multicellular forms  Chlamydomonas  Volvox  Spirogyra  Cladophora  Lichens=a mutualistic relationship between a green algae and a fungus

54. Colonial and multicellular chlorophytes: Volvox (left), Caulerpa (right) Colonial and multicellular chlorophytes: Volvox (left), Caulerpa (right)

55. Chlamydomonas

56. Volvox

57. Spirogyra

58. Chladophora

59. Lichens