1. Characteristics of Protists
Are unicellular or simple multicellular
Eukaryotic
Not plants, fungi or animals
Many are autotrophs and others are heterotrophs
Use flagella, cilia or pseudopodia for locomotion
Reproduce asexually
Reproduce sexually by conjugation

2. Animal-like Protists Sometimes called protozoa Amoeba
Have pseudopodia that are large, rounded cytoplasmic extensions that function both in movement and feeding
Moves by amoeboid movement-cytoplasmic streaming
Prey on smaller protists and bacteria
Live freely , some live in human intestines and cause disease (ulcers)

3. Amoeba

4. Animal-like cont… Paramecium Move by cilia
Found in ponds and slow moving streams that contain plants and decaying organic matter
Asexual-binary fission
Sexual-conjugation (exchange genetic material with the micronucleus)

5. Animal like protist

6. Animal-like…. Sporozoans
Animal parasites (complex life cycle and usually need 2 host)
Plasmodium causes malaria and needs both mosquitoes and humans
Absorb nutrients and destroy host cells
May have killed more people than any other group of pathogens

7. Malaria life cycle
Begins life cycle in mosquito and transfers to a human
Attacks healthy red
Blood cells

8. Animal-like…
Trypanosomes live in the blood of fish, amphibians, reptiles, birds and mammals and are carried from host to host by blood sucking insects
Tsetse fly which lives only in Africa transmits these parasites causing sleeping sickness (increasing fever, lethargy, mental deterioration and coma)

9. Plantlike Protists Most are known as algae
Have chloroplasts and produce their own carbohydrates by photosynthesis but have no true roots, stems or leaves.
Examples: green algae, brown algae, red algae, diatoms, dinoflagellates, golden algae and euglenoids.

10. Multicellular algae

11. Euglena

12. Dinoflagellates – Cause red tide

13. Plantlike… Euglenoids Both plantlike and animal-like
Most are autotrophic but lack a cell wall
Highly motile
Live in fresh water, but a few occupy moist environments such as soil or the digestive tracts of certain animals

14. Funguslike protists (Slime Mold)
Live as individual haploid cells that move about like amoebas
Move as an independent organism, creeping over the ground or swimming in fresh water and ingesting food but when short on food, will cause them to gather together by 1000’s
Produce fruiting bodies that resemble those of fungi

15. Slime mold

16. Funguslike (water molds)
Some are parasitic with fish
Similar means of obtaining nutrients, cell walls made of the same type of material, filamentous bodies and similar enzymes and biochemical pathways
Some biologists hypothesize that chytrids (water mold) are a link between protists and fungi

17. Water mold on a potato

18. Protists and Humans
Produce larger amounts of oxygen, form the foundation of food webs, recycle materials and play a role in several symbiotic relationships
Algal blooms can lead to the depletion of oxygen in water. Red tides produce harmful toxins

19. Protists and humans
Can help scientists understand the movement of leukocytes (White blood cells), provide food and provide important byproducts, such as alginate and agar
Parasitic protists cause malaria, giardiasis (diarrhea, intestinal cramps), cryptosporidiosis (intestinal cysts), trichomoniasis (STD)