1. Ch. 7
Protists

2. Section 3: Protists What is a Protist?
Protists: are eukaryotes that cannot be classified by animals, plants, or fungi
All protists live in moist surroundings
Protists are diverse because most are unicellular, but some are multicellular, some are heterotroph, and autotrophs
Some protists don’t move, while others zoom around their moist surroundings

3. Section 3: Protists Animal-Like Protists
Like animals, animal-like protists are heterotrophs, and most are able to move from place to place to obtain food
Protozoans: animal-like protists, unicellular

4. Section 3: Protists Animal-Like Protists Protozoans with Pseudopods
Pseudopods: “false foot”
Pseudopods form when cytoplasm flows toward one location and the rest of the organism follows
An Amoeba is an example of a protozoan that live in fresh water
Small particles, like those of water, pass easily through the cell membrane into the cytoplasm
If excess water were to build up inside the cell, the amoeba would burst
Contractile vacuole: a structure that collects the extra water and then expels it from the cell

5. Section 3: Protists Animal-Like Protists Protozoans with Cilia
The second group of animal-like protists are the ciliates
Cilia: which are hair-like projections from cells that move with a wavelike motion
Ciliates use their cilia to move and obtain food
The cells of ciliates, like the paramecium has two contractile vacuoles that expel water from the cell.
Has more than one nucleus
Produce asexually by binary fission
What are cilia?

6. Section 3: Protists Animal-Like Protists Protozoans with Flagella
Third group is flagella which are protists that use long, whip-like flagella to move
Some live inside the body of other organisms
Example: one type of flagella live inside the intestines of termites
Symbiosis: interaction between two species; a close relationship in which at least one of the species benefits
Mutualism: when both partners benefit from living together
Example: Giardia is a parasite that lives in humans; comes from wild animals such as beavers

7. Section 3: Protists Animal-Like Protists Protozoans that are Parasites
Fourth type is characterized by the way they live then by the way they move
They are parasites that feed on the cells of body fluids of their hosts
Many have more than one host
Example: Plasmodium: protozoan that causes malaria (disease of the blood)
What is symbiosis?

8. Section 3: Protists Plantlike Protists
Algae: are autotrophs using the suns energy to make their own food
Algae play a significant role in the environment
Example: algae that live near the surface of ponds, lakes, and oceans are an important food source for other organisms in the water
Algae very in size
Unicellular
Multicellular
Live in colonies
Algae very in color
They consists of many pigments

9. Section 3: Protists Plantlike Protists Diatoms
Unicellular protists with beautiful glasslike cell walls
Some float on the surface of water, some attach to rocks in shallow water
Food source for heterotrophs
Move by oozing chemicals out of slits in their cell walls
When they die, their cell walls collect on the bottom of lakes or oceans
Diatomaceous: layer forming coarse substance

10. Section 3: Protists Plantlike Protists Dinoflagellates
Unicellular algae surrounded by stiff plates that look like a suit of armor
Exists in different colors such as green or orange
Glow in the dark
Have 2 flagella help in grooves between their plates
When the flagella beat, the dinoflagellates twirl like toy tops as they move through the water

11. Section 3: Protists Plantlike Protists Euglenoids
Green, unicellular algae that are found mostly in fresh water
Can be either autotrophs or heterotrophs
Whiplike flagellum to help it move

12. Section 3: Protists Plantlike Protists Red Algae Multicellular seaweed
Grow more than 260m below the ocean’s surface
People use red algae in many ways:
Ice cream
Hair conditioner
Eat it fresh, dried, or toasted (Asian cultures)

13. Section 3: Protists Plantlike Protists Green Algae
Very diverse, unicellular, but some form colonies and are multicellular
Live in fresh, salt water, or on land found on rocks, crevices on tree bark, or in moist soils
Green algae and plants that live on land have similar characteristics
Same chlorophyll

14. Section: Protists Plantlike Protists Brown Algae
Example: seaweed, Giant kelp
Different pigments besides brown are: green, yellow, and orange
Plantlike structures: holdfasts, stalks (leaf-like structures), and gas-filled sacs called bladders
Live in cool, rock waters off the coast of the Atlantic Ocean
People eat brown algae and its used as a thickener in pudding
What color pigments can brown algae contain?

15. Section 3: Protists Funguslike Protists
Spore: is a tiny cell that is able to grow into a new organism
Like fungi, funguslike protists are hetertrophs, have cell walls, and use spores to reproduce
Slime Molds
Brilliantly colored
Live on forest floors
Ooze on the surfaces of decaying materials, feeding on bacteria and other microorganisms
Life cycle: tiny amoeba-like cells, use pseudopods to feed and creep around, cells grow bigger and form a jellylike mass
When the environment conditions become harsh, the mass releases spores

16. Section 3: Protists Funguslike Protists Water Molds and Downy Mildews
Live in water or moist places
Grow as tiny threads and look like fuzz
Attack many food crops such as: potatoes, corn, and grapes
In what environments are water molds found?