Bio 201 Review

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  • Topic: Evolution, DNA, Snowball Earth
  • Pages : 2 (644 words )
  • Download(s) : 22
  • Published : April 22, 2013
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Origin of Life
1. The four stages of hypothesis for the origin of life on Earth by chemical evolution is * Abiotic synthesis of small organic molecules
* The joining of small molecules into macromolecules
* Packaging of these molecules into protobionts
* The origin of self replicating molecules that made inheritance possible. 2. A.I. Oparin, and J.B.S. Haldane hypothesized a reducing environment. Stanley Miller and Harold Urey did lab experiments that showed that the abiotic synthesis of organic molecules in a reducing atmosphere is possible. These would occur in water for oceans. 3. The first genetic material was probably RNA. Early protobionts with self replicating, catalytic RNA would have been more effective at using resources and would have increased in # through natural selection. Ribozymes catalyze many reactions. Ie. Ribozymes can make complementary copies of short stretches of their own sequence or other short pieces of RNA. 4. Natural selection may have worked in an early RNA world because early protobionts with self replicating, catalytic RNA would have been more effecting at using resources and would have increased in number through natural selection. 5. (I know it’s the same as 4) Natural selection may have worked in an early RNA world because early protobionts with self replicating, catalytic RNA would have been more effecting at using resources and would have increased in number through natural selection. Major Events in the History of Life

1. The fossil record provides an incomplete chronicle of evolutionary change because the fossil records favors species that existed for a long time, were abundant and wide spread in certain kinds of environment and had hard shells. 2. Radiometric dating can be used to determine the absolute age of rocks strata because a radioactive parent isotope decays to a daughter isotope at a constant rate. The rate of decay is measured in half life. Measurement of magnetism of...
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