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Chapter 20 The Origin and Evolution of Life
In the beginning…
Explain the big bang theory
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When did the solar system form?
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Origin of Earth
How would the Earth be described when it was first formed?
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What were atmospheric gases when the Earth was first formed?
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What two gases that was not present at Earth first formation?
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When the Earth’s crust cooled was begin to form_________________________
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Synthesis of Organic Compounds
Evidence from neighboring bodies in our solar system indicates that precursors for building
_____________________ molecules must have been present on primitive Earth.
What energy was present when the Earth was first formed?
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What did Stanley Miller show in his lab apparatus?
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What did Sidney Fox experiment show?
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Origin of Agents of Metabolism
During the early history of the earth, enzymes, ATP, and other molecules could have
assembled ________________________________.
Origin of Self-Replicating Systems
From accumulated organic compounds emerged replicating systems consisting of DNA,
____________ and __________________.
What have similar structure to RNA?
Perhaps RNA templates set up an RNA world that preceded DNA’s dominance as the main
informational molecule.
How DNA entered the picture is not clear, but we do know that some reactions were more
probable than others.
Origin of Plasma Membrane
What must a cell for metabolism to occur in cell?
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What was used as a template for proteins?
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Origin of Prokaryotic and Eukaryotic Cells
The original prokaryotes line split into archaebacteria, eubacteria and a line leading to
______________________.
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What did the evolution of the cyclic pathway of photosynthesis in eubacteria tap?
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In what eon did the noncyclic pathway evolve the eubacteria and then later the eukaryotic
cells?
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Where did the organelles come from?
Origin of the nucleus and ER
What cell organelle was thought to have come from the prokaryotic cells infolding of the
plasma membrane?
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Theory of Endosymbiosis:
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What are the two organelles responsible for endosymbiosis? What are the evidence of the
organelles to suggest endosymbiosis?
Paleozoic Era (550-240 million years ago)
Period
Plants (found in
Animals (found in
thes period)
this period)
Cambrian
Ordovician
Siluarian and
Devonian
Carboniferous
Permian
Major changes to
the
plates/environment
Mesozoic Era (240-65 million years ago)
Period
Plants (found in
thes period)
Animals (found in
this period)
Major changes to
the
plates/environment
Triassic
Jurassic
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What happen at the end of the Mesozoic era with the temperature?
 What is one hypothesis of why the dinosaurs died/evolved? Where did it supposedly happen?
Cenozoic Era (most recent era)
Period
Plants (found in
Animals (found in Major changes to
this period)
this period)
the
plates/environment
Quaternary
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What did the break up of Pangaea suggest during the Cenozoic Era?
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When did the human civilization begin? What has this human civilization toward civilization
suggest about extinction?