KINGDOM PROTISTA

“The Junk Drawer” of Classification

•Classified based on what they are NOT – they are NOT fungi, plants, or animals, but they are eukaryotic (in fact, they were probably the FIRST organisms to evolve a nucleus)

•First to reproduce sexually; first multicellular organisms

•Most are unicellular & microscopic

•Live where ever there is moisture (water)

•Historically, divided into algae (plant-like) and protozoa (animal-like)

Types of Protists

Use the following slides to complete the table in your notes. Look for:

* Distinguishing characteristics

* How they obtain nutrition

* Examples and illustrations

Types of Protists

• Ameboids

– Amoeba

– Foraminifera

• Algae

– Green

– Red

– Brown

• Diatoms

• Flagellates

– Dinoflagellates

– Euglenoids

– Kinetoplastids

– Cilliates

• Molds

• Sporozoans

Ameboid: Ameoba (phylum Rhizopoda)

• No cell wall, no flagella, extremely flexible

• Pseudopodia: for eating and motility

Pseudo = “false” podium = “feet”

• Heterotrophic: engulf prey with pseudopodia by endocytosis/phagocytosis

• Reproduction:

mostly asexual

through binary fission

Amoeba engulfing a paramecium with pseudopodia – An example of phagocytosis (a form of heterotrophy)

Ameboid: phylum Foraminifera

• note the long pseudopodia coming out of the shell of calcium carbonate

• nutrition: heterotrophic and photosynthetic (depending on the species)

• compose sedimentary rock

Ameboid: Heliozoans and Radiolarans

• Related to amoebas – pseudopodia & phagocytosis

• Long, slender pseudopodia coming from the heliozoan on the left

• Heliozoans are freshwater; radiolarans are marine (saltwater)

• Both form the ooze on the floor of these bodies of water with the shells left from their dead bodies

Phylum Algae

• Autotrophic: photosynthesis

• Unicellular or multicellular

• Named according to pigment

– Pigment is what makes color

• Produce 1/3 of oxygen in atmosphere (more than the plantae kingdom)

25 nm

60 m

Golden algae - microscopic Brown algae - macroscopic; this is a kelpforest, supplying habitat and food for an entire ecosystem

multinucleate green algae; these

are NOT leaves

Volvox (microscopic)

Red Algae Green Algae

Diatoms: Phylum Bacillariophyta

• Photosynthetic

• Unicellular

• Two part shell (like a box and lid) made of silica

• When the shell separates, each half regenerates another matching half

• Shell deposits are mined and used for commercial purposes

Flagellates: phylum Euglanoid

• Use flagella for motility

• Have an eyespot for phototaxis

• Have a contractile vacuole for water balance

• Autotrophic/ photosynthetic (chloroplasts) AND heterotrophic

Flagellates: phylum Dinoflagellate

• Photosynthetic AND heterotrophic

• Planktonic, phytoplankton (phyto = plant)

• Responsible for red tide (named for the photosynthetic pigment they contain); “blooms” of these organisms cause massive kills due to the toxins they produce

• Heterotrophic species use the toxins to stun prey (like fish) and then feed on its body fluids

• Some are bioluminescent (bio = life, lumin = light)

• Also related to the euglenoids (note the presence of the flagella)

Phylum Flagellates: • Trypanosoma – genus of the protist that causes African sleeping

sickness in humans (host) following the bite of the tsetse fly (vector)

• Giardia – genus of another flagellated protist that causes disease in humans

• Closely related to the euglenoids because they have similar body coverings

Paramecium: phylum Ciliophra All members of this group have cilia. Note there are even cilia lining the oral groove

*contractile vacuole

*micro and macro nuclei

*Heterotrophic – food enters through oral groove, food vacuole forms, lysosomes help digest food

LOOK! Waste leaving cell (exocytosis)

Ciliophorans: Stentor and Paramecium

Slime molds: phylum Myxomycota

• Protists that aggregate (clump together) in times of stress to form spore-producing bodies

• Look like fungi but are NOT (no chitin in cell walls)

• Heterotrophic – engulf bacteria and organic material

Molds: plylum Oomycota

• heterotrophic

• commonly found in very wet environments growing on dead or decaying orgahnisms, such as on the fish below; called “mycota” because they look like fungi but are NOT (no chitin in cell walls)

• Many are pathogenic

– Late blight was responsible for the Irish potato famine

Sporozoan: phylum Apicomplexa

CHARACTERISTICS

• Spore-forming

• Non-motile

• Unicellular

• Parasitic

DISEASES

• Malaria: host – vertebrates; spread by mosquitoes

• Toxoplasmosis: host – humans & cats

• Cattle tick fever: host – cattle, mice, humans, deer, dogs

• Cryptosporidiosis: host – cattle humans, birds, deer, dogs, cats

Malaria sporozoans of genus Plasmodium

Protista Vocabulary This list may not be complete for YOU.

If you don’t know these words (or any others in this unit), look them up or ASK!

Colony Nonmotile/motile/sessile

Aggregation Conjugation

Multicellular Alternation of generations

Complex multicellularity Heterotroph/autotroph

Pseudopodia Photosynthetic

Flagella Gamete

Cilia Spore

Planktonic/plankton Host

Silica Vector

Spore Parasitic/saprophytic

Phototaxis Contractile vacuole

Rhizopoda

Amoeba, related organisms

Flexible, no cell wall, pseudopodia, related – shells

Heterotrophs – phagocytosis

p. 464

Euglenophyta

Euglena and related flagellates

Flagella

Eye spots

Autotrophic – photosynthetic & heterotrophic

p. 467

Ciliophora

Paramecium and related ciliates

Cilia

Contractile vacuole

Oral groove

Heterotrophic p. 469

Dinoflagellates Planktonic

Flagellated

Toxic – red tide

Heterotrophic & autotrophic/photosynthetic

p. 467

Bacillariophyta

Diatoms

Shells of silica

Shoe box like shell

Planktonic

Photosynthetic p. 466

Algae (golden, brown, red & green)

Many multicellular Photosynthetic p. 461, 465

“-mycota” groups; water molds & slime molds

Fungus-like

Some aggregate in times of stress; spores

Heterotrophic p. 470

Sporozoans

Complex life cycle - Apicomplexa

nonmotile, unicellular, parasitic, spore-forming, disease-causing

Heterotrophic p. 471 & p. 473