Kingdom Protista What is a Protist A Protist

Kingdom Protista

What is a Protist? �A Protist is any organism that is not a plant, animal, fungus, or prokaryote. �Very diverse kingdom �Single celled Multicellular �Range in size from μm to 50 m+ �Plant like, animal like and fungus like!

Evolution of Protists �Protista comes from Greek words meaning “the very first” �First eukaryotes (1. 5 billion years ago) �May have evolved through the endosymbiosis of prokaryotic cells

Classification of Protists �Grouped according to how they obtain nutrition. � 3 main groups: animal like plant like fungus like

Animal-like Protists �Once called protozoa (first animals) �Heterotrophs �unicellular �Grouped according to their method of movement. � 4 Groups: Zooflagellates Sarcodines Ciliates Sporozoans

Zooflagellates �Belong to phylum Zoomastigina �Swim using flagella �Feed by absorbing �Live in lakes, streams, and bodies of other organisms �Examples: Trichonympha & Trypanosoma

Sarcodines � Belong to phylum Sarcodina � Live in water � Use pseudopods for movement and feeding � Example: Amoeba � move by streaming cytoplasm into pseudopods (amoeboid movement) � http: //www. youtube. com/watch? v=7 p. R 7 TNz. J_p. A

� Other sarcodines: � Foraminiferans have shells made of Ca. CO 3 � Heliozoans (radiolarians) have shells made of Si. O 2

Ciliates � Belong to phylum Ciliophora � Use cilia for movement and feeding � Most complex unicellular protists � Example : Paramecium � http: //www. youtube. com/watch? v=fmw. N_m. D 7 Tv. Y

�Special features of ciliates: �Trichocysts for defense �Macronucleus – working nucleus �Micronucleus – “back up copy” of genes �Become genetically different by conjugation

Sporozoans �Belong to phylum Sporozoa �No means of movement �All parasitic with complex life cycles involving more than one host �Example: Plasmodium (causes malaria)

Diseases caused by Animal-like Protists �African sleeping sickness �Dysentary �Malaria

Ecology of Animal-like Protists �Some live symbiotically within other organisms �Parasites �Decomposers �Part of food chain