“The Junk Drawer” of Classification KINGDOM PROTISTA “The Junk Drawer” of Classification

Classified based on what they are NOT – they are NOT fungi, plants, or animals, but they are eukaryotes (in fact, they were probably the FIRST of the Eukarya) Most are unicellular & microscopic Groups (phyla) are based on physical characteristics (such as motility) and nutritional characteristics (heterotroph/autotroph)

First to reproduce sexually; first multicellular organisms Live where ever there is moisture Historically, divided into algae (plant-like) and protozoa (animal-like)

Rhizopods Ex) Amoeba Flexible surface, no cell wall, pseudopodia Heterotrophs – engulf prey with pseudopodia; endocytosis/phagocytosis nucleus pseudopodia

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

Heliozoans and Radiolarans * Related to amoebas – pseudopodia & phagocytosis Note the long, slender pseudopodia coming from the heliozoan on the left Heliozoans are freshwater; radiolarans are marine Both form the ooze on the floor of these bodies of water with the shells left from their dead bodies

Foraminiferans – another organism related to the amoebas; note the long pseudopodia coming out of the shell of calcium carbonate - compose sedimentary rock - both heterotrophic and photosynthetic (depending on the species)

Euglenoids/flagellates Example – Euglena Called flagellates because of their mode of motility Have an eyespot for phototaxis Have a contractile vacuole for water balance Autotrophic/photosynthetic (look at the chloroplasts!) AND heterotrophic

Trypanosoma – genus of the protist that causes African sleeping sickness in humans (host) following the bite of the tsetse fly (vector) Closely related to the euglenoids because they have similar body coverings.

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

Ciliophora - ciliates Example - Paramecium All members of this group have cilia. Note there are even cilia lining the oral groove *Have a contractile vacuole *Have micro and macro nuclei *Heterotrophic – food enters through oral groove, food vacuole forms, lysosomes help digest food LOOK! Waste leaving cell via exocytosis

Another look at Ciliophorans: Stentor and Paramecium FYI – Not in your notes Another look at Ciliophorans: Stentor and Paramecium

Dinoflagellates Planktonic, photosynthetic protists – called phytoplankton (phyto = plant) AND heterotrophic species as well Responsible for red tide (named for the photosynthetic pigment they contain); “blooms” of these organisms cause massive fish deaths due to the toxins they produce Heterotrophic species use the toxins to stun prey (like fish) and then feed on its body fluids

Shells made of silica house the photosynthetic organism inside Diatoms Another group of protists (actually related to water molds and golden & brown algaes) Shells made of silica house the photosynthetic organism inside The shells are in two parts, fitting together like a shoe box or Petri dish

The Algae Algae – collective term referring to all of the photosynthetic, plant-like protists; alga – singular; algal – adjective Multicellular Photosynthetic – the algae along with other photosynthetic protists are the largest group of producers on Earth, producing 1/3 of the oxygen Algae rocks. Chuck knows.

Algae Have a variety of pigments, on which the name of each group is based (remember, -phyta means “plant”) Golden algae – Chrysophyta; related to diatoms Brown algae – Phaeophyta; “seaweed”; also closely related to the diatoms; kelp Red algae – Rhodophyta; includes some “seaweeds” but not all. Form a separate group from the golden & browns algaes and the green algae; some species are heterotrophic Green algae – Chlorophyta; “seaweeds”; have chlorophyll similar to plants; gave rise to the plant kingdom Volvox (microscopic)

Water Mold Oomycota – heterotrophic protist commonly found in very wet environments growing on dead or decaying organisms, such as on the fish below; called “mycota” because they look like fungi (but they’re NOT) - late blight, a water mold, was responsible for the Irish potato famine

Slime Molds Protists that aggregate in times of stress to form spore-producing bodies Heterotrophic Look like fungi but are NOT

Diseases caused include: Sporozoans Protists that are: Nonmotile *Unicellular Parasitic *Spore-forming Disease-causing *Heterotrophic Diseases caused include: Malaria (host – vertebrates; vector - mosquito) 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