Protista Kingdoms

The Big Picture

Kingdom Protista– Animal-like Protists– Plant-like Protists

– Fungus-like Protists

Kingdom Protista

All are Eukaryotic Any organism that is not a member of the

other kingdoms (the junk drawer) Classified based on how they obtain

nutrition– Animal-like Protists are heterotrophic.– Plant-like Protists are photoautotrophic.– Fungus-like Protists are decomposers or

parasites.

I. Animal-Like Protists

4 Phyla classified by movement:

1) Zooflagellates: - swim using 1 or 2 flagella- reproduce asexually by binary fission and can absorb nutrients through cell membrane

2) Sarcodines:- use pseudopodia (false feet) for movement

and have food vacuoles for storage

- examples: Amoeba, Foraminiferans (CaCO3 shells, White Cliffs of Dover), Heliozoans (silica shells look like sun’s rays)

I. Animal-Like Protists3) Ciliates:

- unicellular & use cilia to move and feed

- usually reproduce asexually but can use conjugation (sexual reproduction)- have complex organelles including:macronuclei (holds “day-to-day” genes) micronuclei (holds all genes) important for reproductioncontractile vacuoles (gets rid of excess water)anal pores (region where waste is excreted) gullets (depressed regions where food gathers)- example: Paramecium

4) Sporozoans:

- sessile (do not move)

- parasites

What do Animal-Like Protists Do?

Trichonympha lives in termite digestive systems allowing them to digest cellulose in wood (What kind of ecological relationship is this?)

Animal-Like Protists can Cause Diseases like:– African Sleeping Sickness (Trypanosoma)- fly born– Malaria (Plasmodium)- mosquito born (in 2008- 190 to 311

million cases. 708k- >1 mil people died)

– Amoebic Dysentery (Entamoeba)– Giardia in water can cause digestive problems if

water is not boiled or iodized.

II. Plant-Like Protists 7 types (unicellular types in red):

1) Euglenophytes – 2 flagella, no cell wall

2) Dinoflagellates – ½ photosynthetic, ½ heterotrophic 3) Chrysophytes – gold-colored chloroplasts

4) Diatoms – beautiful, silicon-rich cell walls

5) Red Algae – can live deep in ocean due to phycobilins (pigments)

6) Brown Algae – largest, most complex algae containing fucoxanthin (brown pigment)

7) Green Algae – have same pigments and cell wall composition as plants; can be colonial, uni-, or multicellular

II. Plant-Like Protists

Euglenophytes:– Live in freshwater– unicellular– 2 flagella– no cell wall– Can be photosynthetic

OR heterotrophic

II. Plant-Like Protists Dinoflagellates

– 2 flagella– Spin through the water like a top– Protective coat made of cellulose and silica– Some produce toxins and cause “red tide” in

coastal areas.

Red tide- algae in bloom

Can affect humans- if contaminated shell fish is consumed

II. Plant-Like Protists

Chrysophytes:– Golden algae– Large amounts of

carotenoids– Store energy as oil – Are important in the

formation of petroleum deposits

II. Plant-Like Protists Diatoms:

– Both fresh- and saltwater– Cell walls (shells) made of 2 silicon pieces that fit

together like a box with a lid– When they die, their cell walls sink and accumulate,

creating diatomaceous earth (abrasive used for toothpaste, detergents, insulation, dynamite, filters,etc)

II. Plant-Like Protists Red Algae (Rhodophyta):

– Most are salt-water species– Smaller than brown algae– Contain phycobilins, pigments

that can absorb wavelengths of light deep in the water

– Some are coated with carageenan, a sticky coating used for cosmetics, gelatin capsules, and some cheeses

– Porphyra, or nori, is used in sushi rolls.

II. Plant-Like Protists

Brown Algae (Phaeophyta):– Mostly marine– Contain fucoxanthin, a pigment giving it its brown

color– Multicellular and large (often > 45 m)– Example: Kelp grows along coasts, produce

underwater “forests,” and are among the largest organisms on Earth.

– Brown Algae can be used as a thickener in foods like ice cream or pudding.

II. Plant-Like Protists Green Algae

(Chlorophyta):– Can be freshwater or

marine– Have same pigments

as plants– Major component of

marine plankton– Thought to be

ancestors of the plant kingdom.

What are Plant-Like Protists Used For?

Algae is the “grass” of the sea for many animals.

Photosynthesis: about ½ of all photosynthesis is done by algae

III. Fungus-Like Protists

Heterotrophs that decompose dead/decaying organic matter.

Unlike fungi, they have centrioles and lack chitin in their cell walls.

Slime Molds and Water Molds

III. Fungus-Like Protists Slime Mold http://youtu.be/GScyw3ammmk

– Cellular Slime Molds: • individual cells remain distinct

throughout life• Single cells migrate to one uniform

colony• Colony produces a fruiting body

with spores

– Plasmodial Slime Molds (Acellular)

• Single-celled with many nuclei (can be several meters long)

• Produces sporangia which release spores

III. Fungus-Like Protists Water Molds

• White, fuzzy organisms that grow on dead organic matter in water and are plant parasites

The Water Mold Phytophthora infestans caused the Irish Potato Famine of 1845.– Potatoes were a major food crop in

Ireland since being introduced from South America.

– This water mold destroyed entire potato crops, ultimately causing more than 400,000 people to starve.

– Many Irish migrated to America after this event.