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28 Cards in this Set
- Front
- Back
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How old is Earth
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4.5 billion years |
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During formation |
-Heavy toward core |
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4bya |
earths surface began solidifying and for liquid water to accumulate |
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"Hadean" time |
no o2 |
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4 Overlapping stages
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-Origin of organic molecules -Polymerization -Boundaries -RNA world |
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Haldane & Oparin (1920) Stage 1: Origin of organic molecules |
prebiotic/Abiotic synthesis |
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Stanley Miller Experiment (1953) |
-lack of O2 -Lots of H2O, H, CH4, NH3 |
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Extraterrestrial Hypothesis
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Meteorites containing organic molecules hit and introduces them to earth |
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Deep-sea Vent hypothesis |
extreme temperature gradient |
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Protobiont |
-Distinct internal environment -Metabolic and catalytic functions -crude self-replication |
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Coacervates |
Skin of water and solid droplet of protein and carbonhydrate |
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Liposomes
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Phospholipid bilayer hollow sphere of phospholipid filled with water |
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Key RNA functions
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-Store infor in base sequence -Self-replication (base pairing) -Enzymatic function - ribozymes |
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Types of preservation
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-peat bogs -Ice -mud,gravel,sand -sedimentary rock |
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Radioisotope Dating |
-underestimates |
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Half life |
-decay product accumulates over time |
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How many mass extinctions have we had? |
5
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History divided into? |
Eras Periods |
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Archaean Eon |
first cells (fossils) -prokaryotes little free o2 |
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Proterozoic Eon
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First animals apperared |
-soft bodied aquatic invertebrates first |
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Phanerozoic Eon |
-Paleozoic -Mesozoic -Cenozoic 543 mya- present |
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Paleozoic Era:
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-Cambrian Period d(iversity of animals) -Silurian Period (Colonization of land) -Denovian Period (First tetrapod vertebrates) -Permian Period (Largest known mass extinction 90-95) 550-290mya |
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Mesozoic Era
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Triassic Jurassic Cretaceous Age of dinosaurs mammals appear mass extinction |
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Theropods later lead to?
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Cenozoic Era
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65my to present mammals and flowering plants diversify
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7mya
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ancestors of humans, chimps, gorillas |
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Homo sapiens fossils appears |
170,000 years ago
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