1. Protists
Chapter 20

2. Any organism that is not a plant, animal, fungus, or bacteria.
All Eukaryotes
Most are unicellular; a few multicellular
Classify according to method of nutrition
Animal-like – heterotrophs
Plant-like – photoautotrophs
Fungus-like – decomposers

3. Protozoans – animal-like
Grouped by how they move
Zooflagellates
Swim w/ flagella (most have 1 or 2)
Absorb nutrients through cell membrane
Sarcodines
Use pseudopodia (cytoplasmic extensions) to move and feed – aka amoeboid movement
Feed by surrounding food w/
pseudopodia and forming a food
vacuole around it
Ex. Amoebas, heliozoans
Ex. Foraminiferans – have shells of
calcium carbonate – White Cliffs of Dover, England

4. Protozoans cont. Ciliates Sporozoans
Use cilia (hairlike projections) to move
Ex. Paramecium – has a macronucleus (uses every day) and a micronucleus (a reserve copy of all the genes)
Sporozoans
Parasites - Do not move on their own
Complex life cycles w/ more than one host

5. Protozoans cont. Diseases Malaria – caused by sporozoan Plasmodium
Carried by female Anopheles mosquito
In human – infects liver cells where it moves to red blood cells – causes rbcs to burst = chills and fever
African sleeping sickness – caused by zooflagellate Trypanosoma
Carried by tsetse fly
Infects nerve cells = unconsciousness
Amebic dysentery – caused by sarcodine Entamoeba – Invade intestines

6. Protozoans cont. Ecological importance
Break down organic matter, provide food for small aquatic animals
Trichonympha – lives in guts of termites
Breaks down cellulose in wood for termite to
digest

7. Algae – plant-like Grouped by type of photosynthetic pigments
Are found in phytoplankton – carry out ½ of the photosynthesis on Earth & provide nourishment for many ocean creatures
Euglenophytes – unicellular
2 flagella
Heterotrophic if no sun

8. Algae cont. Chrysophytes – unicellular Diatoms – unicellular
Gold-colored chloroplasts
Ex. Yellow-green algae,
golden-brown algae
Diatoms – unicellular
Box-like shells of silica
Dinoflagellates – unicellular
2 flagella
Autotrophs and heterotrophs
Bioluminescent
Release toxins – produce red
tide

9. Algae cont. Red algae – multicellular Brown algae – multicellular
Contain phycobilins (absorb blue light) which allow them to live at great depths
Brown algae – multicellular
Contain fucoxanthin – brown pigment
Largest
Ex. kelp

10. Algae cont. Green algae Uses uni/multicellular; some colonial
Cell walls of cellulose
Fresh/salt water
Ex. Ulva (sea lettuce), volvox
Uses
Treat stomach ulcers, arthritis
Food – wrap sushi, ice cream, pudding, salad dressing, eggnog, pancake syrup
Industry – paints, plastics, transistors

11. Fungus-like protists Similar to fungi – are decomposers
Different from fungi – lack chitin cell walls
Slime molds
Like damp places rich with
organic matter
Cellular slime molds
Have distinct cell membranes
Plasmodial slime molds
No cell membranes
Form a plasmodium with many
nuclei

12. Fungus-like cont. Water molds Ecological effects Live on dead material
in water or as plant
parasites
Ecological effects
Decomposers
Mildews and blights on plants
Ex. Phytophthora infestans – caused the Irish potato famine