Kingdom Protista

Characteristics

• ALL are eukaryotic

• MOST prefer aquatic environment

• “junk drawer” of the natural world

Classification

• Animal-like

• Plant-like

• Fungus-like

Animal-like Protists

• called protozoans = “first animals”

• no cell wall

• heterotrophic

• classified by how they move

Sarcodines

• move by pseudopodia

• ex: amoeba

• many have shells used in formation of limestone, chalk

• use pseudopodia to engulf food

• reproduce by binary fission

Ciliates

• move by cilia

• reproduce by binary fission or conjugation

• ex: stentor, vorticella, paramecium

Paramecium

Flagellates/Mastigophorans

• move by flagella

• many live inside animals (symbiotic relationship)

• ex: Trypanosoma - causes African Sleeping Sickness

• ex: Giardia - causes severe diarrhea

Sporozoans

• no means of locomotion

• must rely on host

• most are parasitic

• ex: Plasmodium - cause malaria

Plasmodium Life Cycle

Plant-like Protists

• autotrophic

• unicellular or multicellular, some are colonial

• thought to supply approx. 70% of Earth’s oxygen

Euglenoids

• unicellular

• move by flagella

• found in fresh water

• have an eye spot

• ex: euglena

Diatoms

• unicellular

• over 10,000 different species

• found in fresh and salt water

• silicon dioxide shell (glass)

• many commercial uses - pest repellant, car paint, nail polish, tooth paste, cat litter, toxic spill clean up…..

• (technically golden algae)

Dinoflagellates

• unicellular

• 2 flagella

• often have colorful pigments & many produce bioluminescence

• ex: Red Tide

Green Algae

• may be unicellular, multicellular, or colonial

• ex: Chlamydomonas, Volvox, Chlorophyta

Golden Algae

• found mostly in fresh water

• very small group

• AKA: Chrysophyta

Red Algae

• most are multicellular & marine

• can be found very deep

• used as food additive (carrageenan), in cosmetics and hair products and to make agar :)

• also used as Asian food

Brown Algae

• “seaweed”

• most are marine, can be found in very cold water

• range in size from very small to over 100 meters

• many have air bladders

• ex: Giant Kelp

• uses: algin - food stabilizer, Asian food

Fungus-like Protists

• heterotrophic

• have cell walls

• many move by flagella during life cycle

Slime Mold

• begin as single cells that collect together

• prefer moist, nutrient-rich environment

• commonly found in mulch

Water Mold

• AKA downy mildew & white rusts

• feed on decaying organic material (rotting trees, mulch)

• responsible for Ireland’s Great Potato Famine of mid-1800s