CHAPTER 19

PROTISTA

Protists

All Eukaryotes (Domain Eukarya)

Most unicellular, some multicellular, some colonial (volvox)

Autotroph or heterotrophSome have chloroplastsSome have cell walls of cellulose

Classifcation

Classified by what they are not rather than what they are

By their method of obtaining nutrition

Eukaryotes that do not belong to the plant, animal, or fungi kingdom

Categories of Classification

How they obtain nutrition:Animal-Like – ex. AmeobasPlantlike – ex. Green algaeFunguslike – ex. Mildew

Table 19.1 (p.543)

Animal-Like Protists

Like animals:Heterotrophs - (this means?)

Why are they not in the animal kingdom?Unlike animals:

These are unicellular whereas organisms in the animal kingdom are multicellular

Plantlike Protists

Like plants:Autotrophs - make own food through photosynthesis

Unlike plants:Mostly unicellularDo not have roots, leaves, or other typical plant structures

Fuguslike Protists

Like Fungus:Absorb their nutrients from other decaying organisms

Unlike Fungus:Cell walls are differentThese do not have chitin in their cell walls (Fungi do)

Environment

Found in damp or aquatic environments

Diverse Kingdom

These organisms do not fit into the other kingdom categories

This way they can still be classified in an organized fashion

Animal-Like Protists (protozoans)

Classified by how they moveCiliaPseudopodSporozoansFlagella

Cilia

Short, hair-like projections (Fig. 19.4)

Used:To propel themselves through water

To move food particles into the cell

Amoebas

Use a pseudopod to surround a smaller organism, forming a food vacuole

Oxygen and waste products diffuse in and out of the cell

Fig. 19.7 (p.550)

Plantlike Protists

AlgaeDo not have roots, leaves or other structures typical of plants

Fig. 19.11

Plantlike Protists

EuglenaHave plantlike and animal-like characteristics

Usually contain chloroplasts and photosynthesize

Are green in color Fig. 19.16

Volvox

An alga that has a colonial growth patternGrows as a colony

May include hundreds or even thousands of cells that form a hollow ball

Fig. 19.19 (p.558)

Uses of Algae

Food source for animals and people

Very nutritious due to high protein content, minerals, and vitamins

Table 19.2 (p.559)

Where Algae Live

Why must algae live at or near the surface of the water?

Funguslike Protists - Slime Molds

Use spores to reproduceFeed on decaying organic matterAbsorb nutrients through their cell walls

Found in damp, shady placesCell walls usually contain cellulose NEVER chitin (like true Fungi)