Kingdom Protista

1. Kingdom Protista

2. Objectives • Become familiarized with the kingdom Protista. • Know some general characteristics. • Identify three major groups of protists. • Learn a few major protest diseases.

3. The Link Between Bacteria and the Multicellular World • Protista comprise a kingdom that is important for several major evolutionary adaptations that led to the evolution of the three other major kingdoms. • Nucleus • Multicellularity • Mobility • Sexual Reproduction • There are three main groups of protists • Plant-like • Animal-like • Fungal-like

4. The Link Between Bacteria and the Multicellular World • There are plant-like protists that photosynthesize • Dinoflagellates • Euglena • Diatoms • Algae • Plants evolved from some plant-like, photosynthesizing protists.

5. The Link Between Bacteria and the Multicellular World • Some are carnivorous protists that are hunters • Amoebas • Ciliates • Animals evolved from some animal-like protists.

6. The Link Between Bacteria and the Multicellular World • Finally, some are like fungus, because they absorb nutrients from the surroundings and produce spores. • Slime molds. • Fungus evolved from fungal-like protists.

7. Protist: Characteristics • All are Eukaryotic… Have a nucleus • Some motile, some not • Some single-celled, some multicellular. • Variety of Ways to Get Energy • Some are • Carnivorous • Photosynthetic • Chemoautotrophic • Detritivores • Some reproduce sexually, others asexually.

8. Characteristics • Reproduction • Primarily Asexual • Budding • Fragmentation • Spores • Sexual (less common but does happen) • Many events happen in times of stress • Male + Female gametes • Sometimes, protists

9. Characteristics: Mobility • Protists evolved with a variety of ways to get around. • Flagella (though not exclusive to protists) • Cilia (same) • Pseudopodia

10. Protista: Classification • Protista has significant diversity. • You are not expected to remember all the phyla, just some significant species.

11. Protists: Major Groups

12. Protista: Significant Species • Paramecium • Euglena • Amoeba • Volvox • Algae • Plankton (some)

13. Paramecium • Unicellular • Heterotrophic • Cilia • Requires oxygen to live • = aerobic environment • Asexual & Sexual Reproduction • Special Quality • 2 nucleii • Found in most aquatic environments

14. The Euglenoids • Euglenoidsare flagellated protists related to kinetoplastids that do not infect humans • Most prey on bacteria • Some have chloroplasts that evolved from green algae and can detect light with an eyespot • Most live in freshwater and have contractile vacuoles that expel excess water

15. Plankton • The diverse collection of organisms that live in the water column of large bodies of water and are unable to swim against a current. • Includes bacterial, protist, plant, and animal species • They provide a crucial source of food to many large aquatic organisms, such as fish and whales. • Kingdom Protista: grouping of microscopic and mostly single-celled organisms; autotrophs and heterotrophs • Phylum Chrysophyta: golden-brown algae; yellow to golden autotrophic single cells in groups or chains; contributing to deep-sea sediments; phytoplankton. • Phylum Pyrrophyta: fire algae; single cells with flagella, producing most red tides; bioluminescence common; usually considered phytoplankton. • Class Dinophyceae: dinoflagellates • Phylum Sarcodina: radiolarians, foraminiferans, zooplankton. • Phylum Ciliophora: ciliates; zooplankton

16. Group: Amoebozoans • Amoebozoans send out pseudopods, move about, and capture food • Most have no cell walls, shell, or pellicles • Amoebas live as single cells • Example: Amoeba proteus, a freshwater predator • Slime moldsare “social amoebas” • Plasmodial and cellular slime molds • Plasmodial slime moldsspend most of their lives as a plasmodium • A streaming multinucleated mass that feeds on microbes and organic matter • Undergoes mitosis many times without cell division • Develops into spore-bearing fruiting bodies

17. Group: Green Algae • Most green algae are chlorophytes • Chlorella: Single celled, grown as health food • Chlamydomonas: Single celled, freshwater alga • Volvox: Colonial, freshwater alga • Cladophora: Forms long filaments • Ulva: “Sea lettuce” • Codiumfragilis: Branching marine alga • Charophyte algaeinclude several lineages that form a clade with land plants • Desmids: A single-celled, freshwater group • Spirogyra: Forms long filaments • Stoneworts (Chara): Closely related to land plants

18. Group: Red Algae • Red algaeare mostly multi-celled marine algae that live in clear, warm waters • Red accessory pigments (phycobilins) allow red algae to live at greater depths than other algae • Red and green algae share a common ancestor with chloroplasts derived from cyanobacteria • Life cycles vary and are often complex, with both asexual and sexual phases; there is no flagellated stage.

19. Group: Stramenopiles • “KELP” • Brown algaeare multi-celled protists that live in temperate or cool seas; ranging from microscopic filaments to giant kelp • Some brown algae are used commercially • Thickeners (algins), food, fertilizer, herbal supplements (bladderwrack)

20. Group: Flagellated Protozoans • Flagellated protozoans are single-celled protists covered by a pellicle (proteins that help cells retain shape) • They swim in lakes, seas, and the body fluids of animals • They are typically heterotrophic and reproduce asexually by binary fission

21. The Euglenoids • Euglenoidsare flagellated protists related to kinetoplastids that do not infect humans • Most prey on bacteria • Some have chloroplasts that evolved from green algae and can detect light with an eyespot • Most live in freshwater and have contractile vacuoles that expel excess water

22. Foraminiferans & Radiolarians • Heterotrophic single cells with chalky or glassy shells live in great numbers in the world’s oceans; cytoplasm extends through many pores. • Most forams live on the seafloor; others drift as part of the plankton.

23. Phylum Actinopoda • Radiolarians • Silica test • Pseudopodia used for food getting • Asexual reproduction • Mostly marine

24. Phylum Foraminifera Forams • Locomotion and food getting by pseudopodia • Calcium carbonate test • Environment- primarily marine

25. Group: Alveolates/ Ciliates • Ciliates are heterotrophic single cells that move about with the help of cilia • Ciliates reproduce asexually by binary fission or sexually by conjugation.

26. Phylum Ciliophora • Locomotion and food getting by cilia • Pellicle present maintains shape • Contractile vacuoles remove excess water • Sexual reproduction by conjugation • Environment- aquatic • Heterotrophic & parasitic

27. Phylum Ciliophora Stentor • Largest freshwater protozoan • Can regenerate body parts • Cilia covers body for movement & feeding

28. Phylum Ciliophora Didinium This organism is aggressive and has a huge appetite

29. Didinium feeding Attaches to paramecium Starts to ingest Almost completely engulfed

30. Phylum Apicomplexa • Protozoan that causes malaria • Plasmodiumenters bloodstream, travels to liver cells, where they divide and release new spores into the bloodstream. • Parasitic • No locomotion • Reproduce asexually • Transmitted by bite of infected mosquito • Destroys red blood cells

31. Diatoms: probably the coolest looking microorganisms • Diatoms are single-celled or colonial protists that have a two-part silica shell • Shells accumulate on the seafloor (diatomaceous earth) • Most are photosynthetic, with a brown accessory pigment (fucoxanthin) • Major components of phytoplankton