BSC 2011L- Midterm Exam Guide - Comprehensive Notes for the exam ( 13 pages long!)
Document Summary
4. 6 - 3. 9 bya meteoritic bombing & volcanic activity create reducing atmosphere. 3. 9 bya onwards first cells appear = protobionts. How life started: abiotic synthesis of organic molecules, monomers to polymers, self-replicating hereditary material, protobionts. Deep sea vents cause reducing atmosphere and likely where early life started; life relied of sulfur for energy clay minerals lattice structures that facilitates organic matter & provides protection from uv radiation. Rna less stable than dna; does not need enzymes; self replicates; self splices; has geno & phenotype. Coacervates droplet protein/ carbohydrates formed abiotically; self replicate & metabolize. Liposomes lipid bi-layer vesicles formed abiotically; self replicate & metabolize. Endosymbiotic model: small prokaryotes enter host as prey/ parasite, host gain selective advantage, host & endosymbiotic become single organism. ~ 1. 5 bya single cells began aggregating into colonies; multicellularity first evolves. Endosymbiotic model evidence: organelle biochem homologous to prokaryotes, organelles replicate by binary fission, organelles posses own dna.
