BIOL2010 Lecture Notes - Lecture 25: Lynn Margulis, Alphaproteobacteria, Nuclear Membrane
Document Summary
Different cell morphology than bacteria and archaea. Lecture 21: larger, membrane bound organelles, extensive cytoskeleton. Nuclear envelope: holds chromosomes separate from the rest of the cell. Multiple lineages with multicellular: has appeared on multiple branches on the tree, homoplasy, multiple origins, convergent evolution. Different mode of reproduction: can reproduce asexually and sexually. Main synapomorphies of eukarya: nuclear envelope linear chromosomes, membrane-bound organelles. Nuclear envelope: originated by infoldings of cell membrane, advantage: separates transcription dna rna and translation rna protein. If they break away and pinch off, they could surround and protect dna: cell has more control of when and how often genes are expressed. Lecture 25: early photosynthetic chloroplast similar to cyanobacteria. Multicellularity: only found in eukarya, huge difference between human and bacteria and archaea, arose multiple times independently, happened by unicellular organisms sticking together and transfer things back and forth.
