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Published byEvangeline Goodman Modified over 9 years ago
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History of Life Chapter 14 sections 2 and 3 (test will also include 1)
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Big Bang Condensed matter exploded into basic particles Matter cooled and began to coalesce
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Earth and Other Planets Gravity pulled in more debris to form solar systems Planets were further shaped Earth formed about 4.6 bya Excessive rain produced oceans 4 bya
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Radiometric Dating Review – mass number, isotopes Method to determine age of mineral samples Comparison between the level of radioactive isotopes to a known level of stable isotope Measured by the time it takes to convert half of the radioactive isotopes to a stable state
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Early Organic Compounds Early atmosphere was thought to have ammonia, hydrogen, water, methane Oparin – with energy added to catalyze, these compounds would react to form… ?
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Basic Life Molecules Miller-Urey
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Different Theories Miller-Urey simulated primordial soup model – many of those early atmosphere molecules may not have existed Bubble Model – rxns that were thought to have occurred in the atmosphere occurred inside of protected bubbles Beyond Earth – basic organic compounds came from meteors
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Pre-cells Cells Under the extreme conditions of early earth, macromolecules form spheres NOT cells yet because they do not have hereditary material – RNA can store information and act as an enzyme Earliest competition – who can replicate the most? Who can break down the most?
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Early Cell Development FIRST CELL was extremely basic in structure and function – Increasing competition as resources dwindled CHEMOSYNTHESIZERS PHOTOSYNTHESIZERS – cyanobacteria Consider changes and competition amongst the population of earth!
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Adjusting to New Conditions Oxygen is now in the atmosphere! O wow. – Damage – Ozone layer – Aerobic respiration
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Eukaryotes Contain membrane-bound organelles Small aerobic prokaryote was engulfed by a large anaerobic prokaryote = mitochondria Small photosynthetic prokaryote engulfed = chloroplast Evidence = membranes, DNA
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