BIO 124 Chapter Notes - Chapter 25: Choanoflagellate, Red Algae, Ediacaran Biota
16 Mar 2016
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Document Summary
Eukaryotes arose by endosymbiosis more than 1. 8 ba (proterozoic era) o o. Eukaryotes have a nucleus and other membrane enclosed organelles (like mitochondria. & golgi) which allows for more specializaion and compartmentalizaion. Eukaryotes have cytoskeleton that provides support and asymmetric form and allows them to change shape when needed. Early evoluion of eukaryotes o o o o o o. Fossil record for them goes back1. 8 ba but could have been earlier. Earlier eukaryotes had more lexible skeleton - supported irregular cell shape. Origins of complex mulicellularity, sexual life cycles, & eukaryoic photosynthesis is given way to. Because of severe ice ages and environmental changes, eukaryotes began to decline. Rise of large eukaryotes began in ediacaran biota (sot bodied organisms) o o. Iniial diversiicaion, origin of mulicellularity ad other novel features and then 600 ma was rise of large eukaryotes - before this, life was microbial.
