PROTISTS

Domains

Classification Review Domain Kingdom Phylum Class Order Family Genus Species

Protists Protists:Protists: Unicellular eukaryotic organisms – very diverseUnicellular eukaryotic organisms – very diverse Over 115,000 speciesOver 115,000 species Eukaryotic cells - contain membrane-bound organelles (particularly mitichondria & chloroplasts)Eukaryotic cells - contain membrane-bound organelles (particularly mitichondria & chloroplasts) Three major classes of protists (old system but still used)Three major classes of protists (old system but still used) –Animal-like protists –Plant-like protists –Fungus-like protists

First Eukaryotes 1.5 billion years ago

Animal-like Protists Ciliates (Cilia bearing protists)Ciliates (Cilia bearing protists) –Have cilia (short hairlike structures) on their plasma membranes

Paramecium Important features:Important features: Have 2 nucleiHave 2 nuclei MacronucleusMacronucleus MicronucleusMicronucleus Feed by forcing H2O into Gullet forming food vacuolesFeed by forcing H2O into Gullet forming food vacuoles Excrete wastes through anal poreExcrete wastes through anal pore Excrete excess water through use of contractile vacuolesExcrete excess water through use of contractile vacuoles

More ciliates

Phylum Sporozoa Usually parasitic in natureUsually parasitic in nature Example is Plasmodia which causes malaria.Example is Plasmodia which causes malaria. –One of the most deadly diseases to man –Malaria is transmitted by the Anopheles mosquito.

Lifecycle of Plasmodia

Phylum Sarcodina Protists with false feet Use extensions of cytoplasm to move and feed.Use extensions of cytoplasm to move and feed. Extensions are called pseudopods (false feet)Extensions are called pseudopods (false feet)

Amoebas

More amoebas

Plant-like Protists Are usually photosynthetic, and also heterotrophic.Are usually photosynthetic, and also heterotrophic. Most are unicellular, most are motileMost are unicellular, most are motile

Example is euglena. Has a flagellum, is motile Is both heterotrophic & autotrophic

Euglena

Dinoflagellates Have 2 flagella for motilityHave 2 flagella for motility Often have a cellulose coveringOften have a cellulose covering

Diatoms Most abundant form of marine algae.Most abundant form of marine algae. Form silicon (glass) shells to protect themselvesForm silicon (glass) shells to protect themselves

Red Algae (Rhodophyta) Red Algae (Rhodophyta)Red Algae (Rhodophyta) Red TideRed Tide Red algeal bloom

Brown Algae (Rhodophyta) Brown Algae (Rhodophyta)Brown Algae (Rhodophyta) –Most Plant-like of all algae. –Include kelps –Can grow to huge sizes (100') –. Giant Kelp Forest

Fungus like Protists: Fungus like Protists:Fungus like Protists: –Act as decomposers –Often have a slimy appearance/texture, hence their name. –3 types: Plasmodial slime moldsPlasmodial slime molds Cellular slime moldsCellular slime molds Water moldsWater molds

Plasmodial Slime Molds Plasmodial Slime MoldsPlasmodial Slime Molds –Can grow very large, however, is still a single cell (with many nuclei) –Feeding stage is called a plasmodium. –Forms fruiting bodies under stress.

More slime molds

Cellular Slime Molds: Exists a majority of its life cycle as an amoebaExists a majority of its life cycle as an amoeba In times of stress these amoebas unite to form a Pseudoplasmodium, which crawls to another location (slug form), and forms a fruiting bodyIn times of stress these amoebas unite to form a Pseudoplasmodium, which crawls to another location (slug form), and forms a fruiting body

Water molds Water molds : Water molds:Water molds: –Completely aquatic –Often decomposers –Sometimes parasitic Water mold attacking a fish