1. Kingdom Protista

2. Protists Protists are all around us, but we seldom notice them.
Protists are part of nearly every type of moist habitat on Earth from high mountain peaks and rain forests to rivers, lakes, and oceans.
They form the foundation of many ecosystems.

3. Protist Diversity
Kingdom Protista is the most diverse of the six kingdoms.
The more than 200,000 species come in many different shapes, sizes and colors.
They may be unicellular or multicellular.
Some are jellylike blobs; others have shells or cell walls.
They may live as single cells or as a colony.

4. So What IS a Protist?
Basically, any organism that is not a plant, an animal, a fungus, or a prokaryote.
ALL are eukaryotic.
MOST are unicellular.
Multicellular protists are grouped in this kingdom because they are very similar to unicellular protists.

5. Three General Groups
Animal-like Protists—unicellular heterotrophs, most are mobile
Plantlike Protists—photosynthetic autotrophs
Funguslike Protists—look like fungi and function as decomposers
Problem: Categories do not reflect phylogeny

6. Protozoans:Animal-like Protists
Unicellular
Heterotrophs
Feed on other organisms or dead organic matter
Grouped into phyla by the way they move
Some are nonmotile and live as parasites

7. Sarcodines: Bloblike Protozoans
Amoebas, foraminiferans, and heliozoans
Most are marine
Some have shells
Most reproduce asexually
Some can form cysts to survive extreme conditions

8. Amoeba Features Move and feed with pseudopodia No cell wall
No definite shape
Contains food vacuoles to store food

9. Entamoeba: Sarcodine Causes Amebic Dysentery
Cysts form and are passed through feces
Contaminated water, food, dishes spread the disease
Excessive bleeding
“Don’t drink the water!”

10. Zooflagellates: Protozoans with Flagella
Move by whipping one or more flagella from side to side
Absorb food through their cell membranes
May live in lakes and streams
Trichomonas vaginalis causes an STD

11. Trichonympha: Zooflagellate
Lives in the intestines of termites
Help digest the cellulose in wood
Example of mutualism

12. Trypanosoma: Zooflagellate
Cause African Sleeping Sickness
Carried by the tsetse fly
Chills and rashes
Some lapse into a deep, sometimes fatal sleep

13. Ciliates: Protozoans with Cilia
Considered the most complex protozoans
Move by beating the cilia that cover their bodies
Found in every kind of aquatic habitat

14. Paramecium Structures
Macronucleus – “working library” of DNA
Micronucleus – “reserve copy” of DNA
Trichocyst – bottle-shaped structure for defense
Contractile Vacuole – removes excess water
Gullet – food goes in
Anal Pore – waste materials leave

16. Sporozoans: Parasitic Protozoans
Nonmotile
Many produce spores
Toxoplasma – danger for pregnant women
                                                                                             

17. Plasmodium: Sporozoan
Causes malaria
Carried by the Anopheles mosquito
Fever, severe chills, headache, fatigue
Not all strains can be treated
There is no completely effective vaccine

18. Algae: Plantlike Protists
Photosynthetic
No roots, stems or leaves
Contain chlorophyll and other pigments
Pigments important in classification
Major producers of nutrients in aquatic ecosystems
Produce more than half of the oxygen generated by photosynthetic organisms

19. Euglenoids: Plants or Animals?
Autotrophs as well as heterotrophs
Unicellular
Flexible pellicle
Contain chlorophyll
Move with flagella
Can ingest food
Red eyespot

20. Diatoms: Golden Algae Unicellular Photosynthetic Marine and freshwater
Silica shells are like pillboxes with lids
Each species has its own unique shape
Asexual and sexual reproduction

21. Dinoflagellates: Spinning Algae
Unicellular
Cell walls made of cellulose plates
Two flagella cause spinning when they beat
Most are marine
Some symbiotic
Some bioluminescent
Some produce toxins

22. RED TIDES
One species of dinoflagellate produces an extremely strong nerve toxin that can be lethal
Summer population explosions can turns the ocean red and kill tons of fish
Harvesting of shellfish is banned during these times

23. Red Algae: Red Seaweeds
Multicellular
Marine
Tropical waters or along rocky coasts in colder water
Attach to rocks with holdfasts
Contain red and blue pigments for photosynthesis at low light levels

24. Brown Algae: Kelp and Friends
Almost all marine
Almost all cool water
Largest is kelp
Use holdfasts
Many have air bladders to help them float

25. Green Algae: The Most Diverse
Major pigment is chlorophyll
Most are freshwater
Wide variety of forms
Complex reproductive cycles
Many biologists feel ancient green algae were the ancestors of plants

26. Fungus-like Protists
Form delicate, netlike structures on the surface of their food supplies
Obtain energy by decomposing organic materials
Two phyla contain slime molds, and a third phylum contains water molds and downy mildews
Some varieties cause disease

27. Slime Molds Many are beautifully colored
Live in cool, moist places on organic matter
Cellular or plasmodial
Reproduce with spores
Able to move during much of their lifecycle

28. Water Molds & Downy Mildews
Most live in water or moist places
Some feed on dead organisms
Some parasitize plants
Water molds produce flagellated reproductive cells