ZOO 2700 Lecture Notes - Lecture 3: Symbiogenesis, Mesosome, Polyphyly

• School: University of Guelph
• Department: Zoology
• Course: ZOO 2700
• Professor: Alex Smith

Document Summary

No true nucleus: has a septum(during fision, mesosome, cell membrane, cell wall, dna, ribosomes. Eukaryotes: eu= the presence of a nucleus (true, karyo= kernel or seed. Evidence for the serial endosymbiotic theory: mitochondria and chloroplasts have their own dna, mitochondria and chloroplasts divide, different genetic code in mitochondria, double membranes, recent endosymbiotic events in protists. Secondary endosymbioses rrna similarities (btwn bacteria, mitos, chloros) Food vacuole temporarily acts as photosynthetic unit: recently ingested algal cell in food vacuole (benefits from photosynthesis) Theme issue " eukaryotic origins: progress and challenges: defining feature, nucleus, cytoskeleton. Choanoflagellata ~600 spp: heterotrophic, choan= funnal (greek) Animals first appearing: ~600 mya, ediacaran fauna, cambrian explosion Protist vs protozoa: protist- small, single celled eukaryotes, protozoa - "first animals" - animalcule, motile, heterotrophic, 215000 decribed species. Groups are (cid:448)ery di(cid:448)ergent, (cid:449)e don"t kno(cid:449) (cid:449)hich ones are ancestral. Some can switch to heterotrophic mode of life. Kinetoplastida: gut parasites of insects and blood parasites of vertebrates.