BIOL 1202 Lecture : CLASS 3 Notes
Document Summary
The 1st livingorginisms were likely anaerobic prokaryotes: stromatolites: 1st signs of photosyntestic life. Endosymbiont hypothesis: certain organelles especially chloroplasts and mitochondria, arose as mutually beneficial associations between the ancestors of eukaryotic cells and captured bacteria that lived within the cytoplasm of the pre-eukaryotic cells. Evidence that supports the endosymbiont hypothesis: distinctive biochemical features shared by eukaryotic organelles and living bacteria, mitochondria and chloroplasts each contain their own genomes, modern intracellular symbiosis. Origin of mitochondria and chloroplasts: anaerobic, predatory prokaryotic cell engulfs an aerobic bacterium, descendants of engulfed bacterium evolve into mitochondria, mitochondria-containing ell engulfs photosynthetic bacteria. Multicellular organisms: advantages of multicellularity, the first multicellular organism 1 bya. Plants-primitive marine algae: animals-marine invertebrates, the cambrian explosion -544 mya, the number of species of animals drastically increased at that time, almost all modern forms of animals arose at this time. Know the order of events in the evolution of life on earth.
