BIO153H5 Lecture 5: Lecture 5-6 Protists I-II.docx
Document Summary
Mystery of mitochondria constructing phylogeny of eukaryotes. Protists are at the base of aquatic food chains imp for aquatic env. ->look at evolutionary history to get insight on species. All eukaryotes have this its a synapomorphy other organisms don have it. Nuclear envelope originated from folds of the plasma membrane. Plasma membrane folds in ( encloses chromosomes ) formation of nuclear envelope (lose connection to outside membrane) Question1: given this evidence of origin of nuclear envelope, what would you expect in today"s eukaryotes: structure should be similar as cell membrane and nuclear envelope came from same space. Er is around the nucleus by infolding of membrane In today"s eukaryotes, you would expect the er to be connected to the nuclear membrane this is what you see! Similar structures and make up of cell membranes. Archaea and bacteria: transcription & translation occur in same area. Eukaryotes: transcription and translation seperated: diff forms of rna processing, gene expression could be better controlled.
