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11 Cards in this Set
- Front
- Back
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Cell |
- Is the basic unit of life - Today all cells come from pre-existing cells |
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FACT: Oceans were chemically rich, includingcompounds such as cyanide, methane,formaldehyde, ammonia, etc |
FACT 2: The Earth formed as a hot mass of molten rockabout 4.5 billion years ago (BYA)– As it cooled, chemically-rich oceans wereformed from water condensation |
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What are the fundamental propertied of life? |
-Cellular organization -Sensitivity -Growth -Development -Reproduction -Regulation -Homeostasis -Heredity |
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Panspermia |
hypothesis that earth may have been“infected” with life from some other planet
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Earths first organisms emerged around when? |
3.8 and 2.5 BYA |
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When Earths first organisms emerged they lived in what Temperatures? |
Very high temperatures |
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THEORY: -Organic molecules may have extraterrestrial orgins |
THEORY: -Organic molecules may have originated spontaneouslyon early earth |
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Early atmosphere composition not agreed on
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– May have been a reducing atmosphere
- Would have made it easier to form carbon-rich(organic) molecules from inorganic molecules -These organic molecules eventually assembled intofunctional, interdependent units to eventually form cells |
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1953 |
Miller and Urey did and experiment that reproduced early atmosphere |
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Miller and Urey experiment |
– Assembled reducing atmosphere rich in hydrogen with no oxygen gas
– Atmosphere placed over liquid water – Temperature below 100ºC– Simulate lightning by bombarding it withenergy in the form of sparks |
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Miller and Ulrey discovered in a week what? |
• that methane gas (CH4) was converted into other simple carbon compounds – Compounds combined to form simple molecules and then more complex molecules • Later experiments produced more than 30 carbon compounds including amino acids (glycine and alanine) and adenine (component of DNA and RNA) • Thus, the key organic molecules of life could haveformed in the reducing atmosphere of the early earth |
