1. The Hodge Podge Kingdom
PROTISTS
The Hodge Podge Kingdom

2. Protists are Divided into 3 Catagories
The animal-like protists
The plant-like protists
The fungi-like protists

3. Protists are Eukaryotic Can be unicellular or multicellular
Can be motile or not (flagella and cilia)
Can be photoautotrophs or chemoheterotrophs or both
Contain 2 or more chromosomes with many histones and other proteins.

4. Animal-like Protists Phylum Sarcodina (Locomotion is via psuedopodia)
Amoebas: Naked, soft-bodied cells that live in freshwater, marine and soil.
Foraminiferans (many chambered test; composed of CaCO3): primarily marine
Heliozoans: Have fine needle-like psuedopodia radiating from body like sun rays. Largely fresh water
Radiolarians (test is composed of silicon dioxide) found in open, shallow waters.

5. Amoebida

6. Foraminiferans

7. Heliozoida

8. Radiolarian

9. More Radiolarians

10. Sarcodina
Use ameoboid movement made possible by cytoplasmic streaming to get around.
Endoplasm (inner) pushes on ectoplasm (outer) to create the arm-like extention.
Because they live in an aquatic environment they need a contractile vacuole to regulate water pressure inside the cell.

11. Diseases associated with Sarcodina
Ameobic dysentery: Entameoba histolytica
Reproduction
- Binary fission
- Budding
- formation of cysts during times of stress.

12. Animal-like protists (cont.)
Phylum Ciliophora
Paramecium
Reproduces via conjugation and binary fission.
Important parts include oral groove, pellicle, mouth pore, gullet, anal pore, macronucleus and micronucleus.

13. Animal-like protists: Ciliaphora cont.
Reproduction:
Conjugation followed by binary fission
Binary fission alone
Parameciums divide along a transverse line

14. Paramecium

15. Cilliate (Bursaria)

16. Animal-like Protists (cont.)
Phylum Mastigophora
Movement via flagella
Trypanosoma brucei (African trypanosomiasis or sleeping sickness)
Vector: tsetse fly
Trypanosoma cruzi (Chaga’s disease)
Vector: Kissing bug
Trichonomas vaginalis
Giardia lamblia (giardiasis)

17. Trypanosoma

18. Tsetse Fly

19. Giardia

20. Animal-like Protists (cont.)
Phylum Sporozoa
Malaria: life cycle
Toxoplasmosis

21. Anopheles mosquito

23. Toxoplama gondii (intracellular)

25. Plant-like Protists Characteristics Autotrophs
Lack tissue differentiation
Unicellular and muticellular
Aquatic
Contain pyrenoids (organelles that synthesize and store starch.

26. Plant-like Protists cont.
Structure of thallus: body portion of the algae.
Body structure is divided into 3 types.
Unicellular E.g. phytoplankton
Colonial E.g. volvox
Filamentous e.g. Spirogyra
Multicellular e.g. Ulva

27. Plant-like Protists cont.
Classification
They are classified based on color, type of chlorophyll, form of food-storage and cell wall composition.
Reproduction
Some reproduce only via asexual reproduction while other have both asexual and sexual reproduction. See later slides for details.

28. Plant-like Protists cont.
Phylum: Euglenophyta
Euglena (euglenoid)
Photosynthetic pigments
Chlorophylls a and b, carontenoids, xanthophyll.
Movement by flagella. Stigma detects light and euglena move towards it.
Can be heterotrophic if deprived of light.

30. Plant-like Protists cont.
Phylum: Chrysophyta (the golden algae) Yellow-green algae
Most are fresh water algae but a few are found in a marine environment.
golden color due to the pigment fucoxanthin (a carotenoid) which masks the chlorophyll
Stores much of its surplus energy as oil and are important in the formation of petroleum deposits

32. Plant-like Protists cont.
Bacillariophyta: the diatoms
Abundant in both freshwater and marine.
Have shells that are pill box-like that consist of silicon dioxide. Each half of the shell is called a valve.
Some shells are centric (circular or triangular) and are marine.
Others are pennate (rectangular) and are found in freshwater. Move by threads that attach to water surface.

35. Plant-like Protists (cont.)
Phylum Dinoflagellata
dinoflagellates
red tides (Gonyaulax catanella) produces neurotoxin
Some have bioluminescence (Noctiluca)
All have 2 flagella, are unicellular, mostly marine and contain pigments chlorophyll, carotenoids, and other red pigments.

36. Noctiluca scintillans

38. Plant-like Protists (cont.)
Phylum: Rhodophyta (the red algae) but may appear green, purple, or greenish-blk.
Multicellular
Tropical waters and along rocky coasts in colder waters.
Pigments: chlorohyll, phycobilins (red/blue) Good at absorbing green and blue/green light waves which can penetrate below 100 m in water.

39. Rhodophyta cont.
Some have cell walls coated with a sticky substance called carageenan (used in cosmetics, gelatin capsules and cheese).
The cell walls contain agar which is extracted and used to make media for culturing microorganisms.

42. Plant-like Protists (cont.)
Phylum: Phaeophyta (the brown algae)
All are multicellular
Largest are kelp
Pigments include chlorophyll and fucoxanthin
Food is stored as laminarin
Macrocysitis cell walls contain alginate (used as a stabilizer in ice cream).

43. Plant-like Protists (cont.)
Phylum: Phaeophyta (cont.)
Parts of kelp
Body is called thallus
“Roots” are called holdfasts
“Stems” are called stipe.
“Leaves” are called blades.
Air bladders keep thallus afloat allowing access to light
Sargassum serve as floating ecosystem
Contains a commercially important substance called alginate. Alginate is used as a stabilizer in most ice creams.

44. The Sargasso Sea

45. Plant-like Protists(cont.)
Phylum: Chlorophyta (the green algae)
It is believed that this group gave rise to land plants.
Most diverse (7000 identified species)
Can be unicellular or multicellular, colonial or sheets.
Found in fresh water and marine environments
Pigment mostly chorophyll
Store food as starch.
Many reproductive methods
See Ulva for life cycle
Often have symbiotic relationships with fungi (lichens).

46. Fungi-like Protists Chytrids (Phylum Chtidiomycota)
Water molds (Phylum Oomycota)
Slime molds
Acrasiomycota: Cellular slime molds
Myxomycota: Plasmodial slime molds (acellular)

47. Chytrids (Phylum Chtidiomycota)
Are believed to be the evolutionary link between protists and fungi (Share enzymes and biochemical pathways).
Live in fresh water and marine
Some are saprobic decomposers while others are parasites.
Single-celled species produce flagellated asexual spores (1 reason it is in Protista).
Chitin reinforces cell wall.
Cell walls are sieve like between cells allowing flow of cytoplasm throughout mycelium.

48. Water molds (Phylum Oomycota)
Distantly related to red algae
Reproduction
Produce flagellated asexual zoospores which germinate into long thread-like cells forming a thallus.
Sexual reproduction occurs when a connecting tube is formed between oogonia and antheridia. Zygote (2n) develops into new thallus.
Key decomposers of aquatic habitats
Some parasitize
Phytophtlora infestans caused “late blight” and the great Irish potato famine.
Blight is a disease of plants characterized by decay and discoloring of leaves.

49. Fungi-like protists cont.
Slime molds contain 2 phylum
Acrasiomycota: Cellular slime molds
Live as haploid cells that move like amoebas.
Asexually reproduce. Sexual reproduction rare or absent.
When food/water is scarce a chemical is released causing them to gather into a pseudoplasmodium.
Pseudoplasmodium produces fruiting body which produces haploid spores.

50. Acrasiomycota fruit bodies

51. Fungi-like protists cont
Mxyomycota: plasmodial (acellular) slime mold
Acellular because the plamodium (group of feeding cells) lack cell walls & appear as a mass of cytoplasm with thousands of nuclei.
Each nuclei is diploid.
Mass phagocytizes decaying leaves/debris.
When food/water is scarce the plasmodium crawls to an exposed area and forms a stalked fruiting body which undergoes meiosis to produce haploid spores. These spores will give rise to haploid reproductive cells which fuse to form a diploid nucleus.
Mitosis occurs but cytokinesis never does.

52. Fuligo septica: The dog vomit slime mold