Exploring the Kingdom Protista: Diversity and Characteristics

1. Kingdom Protista

2. Characteristics of Kingdom Protista • Very diverse. • Eukaryotic. • Mostly unicellular. • Appeared about 1.5 bya. • Formed by endosymbiosis.

3. Classification of Protists • Animal like protists Zooflagellates Sarcodines Ciliates Sporozoans

4. Classification of Protists Plant Like Protists • Unicellular Euglenophytes Chrysophytes Diatoms Dinoflagellates • Multicellular Red Algae Green Algae Brown Algae

5. Classification, con’t Fungus like Protists • Slime molds • Water molds

6. Zooflagellates • Swim using flagella. • Absorb food through cell membrane. • Asexual (most) and sexual (some).

7. Sarcodines Click to See Amoeba in Motion • Move and eat by PSEUDOPODIA – false feet – cytoplasm projections. • Ameobas are best known. • Form food vacuoles. • Reproduce by mitosis and cytokinesis. Foramnifera – secrete shells of CaCO3 White Cliffs of Dover

8. Ciliates Click to see stalked ciliate • Move with hair like projections called cilia. • Also use cilia for feeding – sweep food particles into the gullet which are then incorporated into food vacuoles. • Use trichocysts for defense. • Contractile vacuole – a way to maintain homeostasis. • Macronuclei and micronuclei. • Reproduce by conjugation and then mitosis. Click to compare flagella and cilia http://upsidedownhippo.com/archives/2005/07/index.html

9. Sporozoans • Do not move on their own. • Parasitic. • Complex life cycles. • Malaria has a vector – Anopheles mosquito. Plasmodium – a sporozoan in Blood – causes MALARIA

10. Other Protozoa Diseases • Trypanosome – African Sleeping Sickness, a zooflagellate – vector is tsetse fly. • Amoeba (sarcodine)– dysentery – Giardia, Entamoeba.

11. The Good Guys Click here to see trichonympha • Trichonympha – lives in gut of termite – digests cellulose into glucose

12. Plant Like Protists Click Here to see a Euglena Party • Euglena. • Unicellular. • No cell wall. • Live as autotrophs in light, as heterotrophs in dark. • Eyespot helps find light. • Pellicle – fancy cell membrane. • Reproduce by binary fission.

13. Chrysophytes • Golden Algae. • Unicellular. • Store food as oil rather than starch. • Sexual and asexual.

14. Diatoms - Bacillariophyta • Unicellular. • Cell walls rich in silicon. • Two pieces like a petri dish.

15. Pyrrophyta - Dinoflagellates • Unicellular. • Some autotrophic, some heterotrophic. • Can luminesce. • Enormous growth called algal bloom – Red Tides – produce toxins.

16. Ecology • Plantlike protists common in fresh and saltwater. • 50% of photosynthesis on Earth from phytoplankton. • Important in ecosystems because they are the base of food chain. • Algae Blooms can deplete resources and disrupt equilibrium.

17. The Algaes • Red, Brown and Green. • Most are multicellular. • Have different proportions of chlorophylls. • Brown Algaes are the giant kelps (Example: Sargassum). • Red Algaes important in coral reefs. • Green algae most like plants- found all over – fresh and salt water. • Cell walls of cellulose. • Same chlorophyll as plants. • Store food as starch.

18. Algae

19. Reproduction – Green Algae

20. Human Uses of Algae • FOOD • Treating ulcers, high blood pressure, arthritis. • Seaweed wrapping for sushi. • Algal products used in ice cream, pudding, salad dressing, candy bars, pancake syrup, eggnog… • Chemicals from algae used to make plastics, paints, waxes, deodorants... • Agar for growing bacteria derived from seaweed.

21. Fungus like Protists Slime molds Click to see slime mold • Like fungi, slime molds absorb nutrients from dead/decaying matter • Some have stages with large multi-nucleated cells formed from by cells fusing together.