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.