Introduction to Eukaryotes

Prokaryote/Eukaryote/Both? 1.“before nucleus” 2.“true nucleus” 3.absence of a cytoskeleton 4.absence of nucleus and membrane-bound organelles 5.animals 6.archaea 7.asexual reproduction 8.bacteria 9.binary fission 10.capsule 11.cell wall 12.cilia 13.circular DNA with no proteins 14.cytoplasm 15.flagellum 16.fungi 17.large ribosomes (80S) 18.larger cells (> 10  m diameter) 19.linear DNA associated with proteins 20.mitosis and meiosis 21.multicellular forms 22.plants 23.plasma membrane 24.presence of a cytoskeleton 25.presence of nucleus and membrane-bound organelles 26.protists 27.sexual reproduction 28.small ribosomes (70S) 29.smaller cells (<5  m diameter) 30.unicellular forms

Endosymbiotic Theory EukaryotesProtistaFungiPlantaeAnimalia Eukaryote Evolution

Evolution of Eukaryotes: ENDOSYMBIOTIC THEORY eukaryotic cells arose from living communities formed by prokaryotic organisms Lynn Margulis Boston University, 1967 Mitochondria & chloroplasts – internal parasite – ingested but not digested Benefits: source of molecules for biochemical activities (e.g., ATP, organic molecules) Evidence/support – Mode of reproduction: splitting – W/ own circular DNA & ribosomes – Surrounding membranes: inner, outer Modern-day symbiosis: Cyanophora paradoxa and Legionella 05%20SJ%20Images/MargulisCheadR.jpghttp:// 05%20SJ%20Images/MargulisCheadR.jpg,

Endosymbiotic Theory EukaryotesProtista Plant-like (unicellular algae) Animal-like (protozoa) Fungus-like (slime molds) FungiPlantaeAnimalia Kingdom Protista

Classification of Protists: ACCORDING TO MODE OF NUTRITION Plant-like protists Animal-like protists Fungus-like protists  photosynthetic  a.k.a unicellular algae  ingestive  a.k.a protozoa  absorptive: decomposers, parasites  Artificial classification! Because of their diversity, biologists cannot agree on how to best classify the protists; best approach for now is the traditional single kingdom

Kingdom Protista: EVOLUTIONARY SIGNIFICANCE First ones arose from prokaryotes, and their descendants gave rise to all plants, fungi, and animals, as well as modern protists.arose from prokaryotes

Protista Plant-like (unicellular algae) Euglenophytes Dinoflagellates Chrysophytes Diatoms Animal-like (protozoa) Zoomastigina Ciliophora Sarcodina Sporozoa Fungus-like (slime molds) Myxomycota Acrasiomycota Oomycota

Plant-like/Fungus-like/Animal-like 1.acrasiomycetes 2.algal blooms, red-tide toxins, and eutrophication indicators 3.apical complex 4.calcium carbonate and silica shells 5.classified according to kind of photosynthetic pigments possessed 6.classified according to means of locomotion 7.coenocytic 8.decomposers 9.diatoms 10.dinoflagellates/bioluminescent algae 11.euglena 12.flagella, cilia, pseudopodia 13.foraminiferans 14.hyphae 15.indicate presence of oil in marine environments 16.myxomycetes 17.non-motile animal parasites that cause african sleeping sickness, amoebiasis, and malaria 18.photosynthetic unicellular algae 19.phytoplankton 20.plant and animal parasites 21.plasmodium 22.protozoa 23.pseudoplasmodium 24.radiolarians 25.recycle sewage and waste materials 26.slime molds 27.symbiotes of corals and giant clams 28.symbiotes of termites that help them digest cellulose 29.water molds/downy mildew 30.yellow-green and golden-brown algae