What Are Protists?

1. What Are Protists? • Kingdom Protista • “odds and ends” • Eukaryotic organisms • Heterotroph, autotroph, or decomposer

2. Several important characteristics: • membrane-bound organelles • complex cilia and flagella • sexual reproduction with gametes • Multi – cellularity

3. Reproduction • Asexually by binary fission, budding, and fragmentation • Sexually by fusion of gametes

4. Sexual Reproduction • Occurs as a response to environmental stress • Zygospore • Adaptation that allows the zygote to survive freezing, drying out, and sun exposure • Multicellular protists can reproduce both sexually and asexually via alternation of generations. • consists of multi - cellular haploid and multi - cellular diploid phases.

5. Classifying Protists • How they they obtain nutrition • Photosynthesis • Breakdown organic material • Capture and eat other protists • Ecological role

6. Animal– Like Protists • Protozoa “first animals” • Ingest other organisms to obtain energy • Unicellular, most can move, and most reproduce asexually by binary fission

7. Amoeboid Protists • Move by using extensions of their cells called pseudopodia • Pseudopodia are also used to surround and engulf food particles • Live in fresh water, in salt water, and in soil • Free-living, but some are parasites

8. Ciliates • Some of the most complex single - celled organisms • Most or all of the body is covered by short, hair - like structures called cilia • Move and hunt for food by beating their cilia

9. Flagellates • Protists that have whip-like structures called flagella. • Some flagellates also have cilia or form pseudopodia. • Can be free-living or parasitic

10. Sporozoans • Animal-like protists that form spore – like cells when they reproduce • They lack flagella, cilia, and pseudopodia and do not move. • All sporozoans are parasitic and cause diseases. (Malaria)

11. Plant – like Protists • Include the organisms known as phytoplankton and algae. • Obtain energy through photosynthesis • Vary in the types of pigments used in photosynthesis and the kinds of molecules used to store energy • Diatoms, Dinoflagellates, algae

12. Diatoms • Photosynthetic, unicellular protists with unique double shells • Their shells are made of silica or calcium carbonate and have distinct patterns.

13. Dinoflagellates • Unicellular protists that typically have two flagella. • Most are photosynthetic, but some are heterotrophic • Most have protective coats that contain silica.

14. Euglenoids • Freshwater protists that have one or two flagella. • Many are photosynthetic, heterotrophic, or both. • Some have an eyespot that helps direct them toward light.

15. Red Algae • Most are multicellular and are usually found in warm ocean waters. • The pigments in red algae absorb blue light that penetrates deep into water. • Red algae grow at greater depths than other algae. • Some have calcium carbonate in their cell walls. • These coralline algae play an important role in the formation of coral reefs.

16. Brown Algae • Multicellular protists that are found in cool ocean environments. • The largest brown algae are kelp that can reach 60 m (197 ft) in length. • The body of a kelp has is made up of a holdfast, a stipe, and blades

17. Green Algae • Very diverse group of protist that form a major part of marine plankton. • Some inhabit damp soil and resemble plants. • Some are symbiotic within the cells of other organisms. • Use chlorophyll for photosynthesis, starch to store energy, and their cell walls contain cellulose.

19. Fungus – like Protists • Absorb nutrients from their environment and reproduce by releasing spores. • Slime Molds • Water Molds and Downy Mildews

20. Protists and Humans • Dysentery • Contaminated water • Giardia, amebiasis • Toxoplasmosis • Litter boxes and uncooked meat • Flu – like symptoms

21. Trichomoniasis • Very common S.T.I • Cryptosporidiosis • Dysentery from uncooked meat and contaminated water • Chagas disease • Kissing bug feces • Few to no symptoms then can become chronic with heart failure, swollen esophagus and large intestine

22. Protists and the Environment • Oxygen production and nutrient recycling • Produce at least half of the Earth’s oxygen • Food webs • Primary producers • Algal blooms • Red tide and eutrophication • Protists symbiosis • Coral, lichen, ungulate digestion