Eukaryotes Unicellular or multicellular Very varied group

Origin and Diversity Probably formed by cells taking in prokaryotic cells and keeping them as organelles –Ex – mitochondria andchloroplasts were probably monerans that were captured

Colonies formed before multicellular Protists Once cells were growing together, they eventually developed specialized functions. –These eventually became attached and relied on each other for those functions. (Kind of like people who live in groups – they become specialized and begin to rely on each other.

Protists are conveniently divided into three groups 1.Animal-Like Protists heterotrophs 2.Plant-Like Protists autotrophs 3.Fungus-Like Protists Decomposers (heterotrophs that eat dead organic matter)

Animal-like protists Often called protozoans Unicellular and don’t have specialized tissues, organs or organ systems.

Animal-like protists - Sarcodines Amoebas – move using pseudopods

Amoeba

Animal-like protists- Zooflagellates Move using flagella

Animal-like protists - ciliophorans Move using cilia These are paramecia These are cilia This is its oral groove

Here is a paramecium dividing by binary fission

Paramecium structure Oral groove

Animal-like protists – sporozoans – always parasites and no way to move on their own Plasmodium is a parasite that you get from a mosquito bite. The disease it causes is malaria, which kills about 3 million people a year around the world. It lives in your red blood cells and destroys them.

Plant-Like protists - algae Autotrophic – by photosynthesis Commonly called algae or seaweed Unicellular or multicellular

Unicellular algae Food for other organisms Dinoflagellates cause red tides and some other harmful algae blooms in the oceans.

diatoms Diatoms – live in glass cases

Diatoms – in fresh and salt water Bottom of food chain Case made of silica (glass-like) Used for abrasives and filters

euglenoids

euglena

Multicellular algae Volvox – colony of Flagellated single cells almost multicellular

Green algae Predominant pigment is chlorophyll Found in all types of water

Red algae Grow in warm salt water Some grow very deep in the ocean or on ice

Brown algae Mostly saltwater Grow in cool salt water Includes largest Protists

Fungus-like protists Slime molds – creep along in an amoeba- like fashion

Protists in the Biosphere Some cause disease –Red tide –African sleeping sickness –Giardia –Potato blight –Malaria

Good uses of protists Plankton – bottom of the food chain Food – carageenan, agar, algin – thickeners and flavor enhancers Seaweed as food Diatoms for filters and as abrasives Indicators of the general health of the environment

The end