PROTISTS

CHAPTER 19

KINGDOM PROTISTA (most diverse kingdom)

All are eukaryotic

Unicellular or multi-cellular

Microscopic or very large

Heterotrophic or autotrophic

Plant-like, animal-like or fungus-like

ORIGIN OF

PROTISTS

ALGAEPlant-like protists

Autotrophs Lack true leaves, roots and stems

Most are aquatic

Produce much of the earth’s oxygen

Basis of the aquatic food chain

Spirogyra

Volvox

Mixed green algae

FUNGAL PROTISTSUnlike fungi, fungus-like protists are able to move and lack chitin in their cell walls.

Decompose dead materials (saprobes)

Make nutrients available to living organismsSlime molds

SLIME MOLD

PROTOZOA (singular: protozoan)

Animal-like protists

All are unicellular heterotrophs

Move by means of cilia, flagella, pseudopodia

Reproduce asexually (some sexually)

Some are parasiticsporozoans

AMOEBASProtozoans with pseudopodia

“False foot”

Extensions of cytoplasm

Aid in movement & feeding

Shapeless

Most live in salt water

Some have shellsForaminiferans

radiolarians

Most reproduce asexually

Some form cystsSurvive unfavorable conditions

FLAGELLATES

Protozoans with one or more flagella

Some are parasiticAfrican Sleeping Sickness

CILIATESProtozoans with cilia

Salt or fresh water

Includes:Paramecium

Vorticella

Stentor

SPOROZOANS

Parasitic protozoansMalaria

Sleeping sickness

Trichimonas

Most produce sporesReproductive cell

Produces a new organism

Plasmodium (causes Malaria)

FUNGUS-LIKE PROTISTSSlime molds

Grow on rotting leaves or decaying tree stumps & logs

Water moldsLive in water or moist places

Appear as fuzzy, white growths

Downy mildewsLive in water or moist places

Cause plant diseases

WATER MOLD

ALGAEPhotosynthesizing protistsFresh or salt waterContain chlorophyllProduce more than half the earth’s oxygenInclude:

Red algaeGreen algaeBrown algaeDiatoms - contain silicaEuglenoidsDinoflagellates DIATOMS

RED ALGAE BROWN ALGAE

DIATOMS

Dinoflagellates: known as “fire algae” (cause red tides)