Chapter 20: Protists Name___________________________________ Period_____________• What is a Protist? o _______________________ cell o Most protists are _____________________ but some are ______________________ o Not members of the kingdoms ________________________________________________________ o Protists are a diverse group that may include more than ______________ species• Origin of Eukaryotic Cells o ___________________________ bacteria evolved in the seas of the Precambrian o By 2.2 bya, _______________ filled the water, and the Earth rusted o ________________began accumulating in the atmosphere, and the sky turned_____________…in several hundred million years o Precambrian Seas (figure) o With all the oxygen in the atmosphere, ________________________________ evolved as a more efficient method of organic energy use o Prokaryotes that used this new form of metabolism began evolving __________________________ o By _______________ eukaryotes’ ancestor had evolved Endosymbiotic theory o Theory that eukaryotic cells o Arose from ________________________ formed by prokaryotic cells o Formed from a ____________________among several different prokaryotic organisms o By __________________________________, Boston University o Evidence: mitochondria and chloroplasts are similar to bacteria _____________________________ _____________________________DNA _____________________________structure Divide by _____________________________ __________________________&________________________________machinery
• Classification of Protists o Protists are so diverse that biologists suggest that they should be broken up into several kingdoms o Polyphyletic, two or more ancestors _______ sequencing _________ structure o Currently five candidate kingdoms (Others listed do not yet have suggested kingdoms.) Candidate Kingdom: Archaezoa Lack _____________________________ _____________________________ similar to prokaryotes Diplomondida o _____________________________ o Free-living and commensal o Giardia--parasite Giardiasis—Hiker’s diarrhea Candidate Kingdom: Euglenozoa All _____________________________ Euglenozoa o ______ flagella o _____________________________: chlorphylls a and b o Euglena Euglena movement Kinetoplastids o _____________________________flagella o parasites o Trypanasoma—_____________________________ Candidate Kingdom: Alveolata Alvoeoli—small cavities under cell surface _____________________________ or _____________________________ Dinoflagellates o Dinoflagellate ceratium o _____________________________ Apicomplexans o Apicomplexan—Plasmodium o _____________________________ Ciliates o Paramecium caudatum Vorticella sp.
Protists with _____________________________ Motile o “False Feet” extension of cytoplasm & cell membrane _____________________________ o Feed on algae, bacteria and other protists o Detritvores o Parasites Rhizopods--Amoebas Actinopods o Heliozoan o Radiozoan Foraminifera Candidate Kingdom: Stramenopila Algae o Photosynthesis, but use Chlorophyl _____ not_____ as in plants o Store energy in a different starch o Diatoms o Golden algae o Brown Algae Oomycetes o _____________________________ Absorptive nutrition & parasitic o Cell walls _____________________________, not chitin as fungi o _____________________________cells, absent in fungi Water Molds Achlya Downy mildews Phytophythora infestans Potato Blight caused _____________________________in Ireland, 1845-51 Plant rusts Plasmopara viticola
Candidate Kingdom: Rhodophyta Red Algae No _____________________________flagella, ever Photosynthetic o Phylocobilin pigments, absorb _________________________of deep waters o Store energy as “Floridean starch” Cell walls with agar & carageenan Human Uses o _____________________________ o _____________________________ Chlorophyta—Green Algae Photosynthetic Chlorophyl __________________________________________________________ Storage as _____________________________ Mutualistic, _____________________________ Ancestors of modern plants o Sometime included in _____________________________ Sprirophyta Volvox Ulva Phytoplankton o The population of small _____________________________ organisms near the surface of the ocean o About _____________________________on earth occurs in phytoplankton Algal Blooms o Sometimes populations of algae grows in enormous masses o deplete the water of _____________________________ and can _____________________________ the water
Fungus-like Protists: Slime Molds Like fungi, o _____________________________, decomposers o _____________________________ Unlike fungi o Have centrioles o Lack _____________________________cell walls Myxomycota: Plasmodial Slime Mold o A _____________________________-like protoplasm that contains _____________________________within a single cell membrane o When food grows scarce, they stop moving and grow _____________________________. Dictyosteliomycota : Cellular Slime Mold o live as _____________________________-like cells moving about feeding on bacteria. o When food becomes scarce, they combine into a ____________ ______________________________________________. o This migrates to a new area before developing into a ____________ ________________that produces and releases spores. o Each spore then develops into a _____________________________-like cell.