Ch.12 Geology 1401 – Flashcards
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How is Earth unique from other planets?
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-Earth's core creates a magnetic field that is just strong enough to protect the surface from solar wind
-Earth's atmosphere supports varied forms of life
-Earth's distance from the Sun produces surface temperatures that support varied forms of life
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How long ago did life first appear on Earth?
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at least 3.5 billion years ago
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What is the relationship between planetesimals and protoplanets?
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-Planetesimals are smaller than protoplanets.
-Planetesimals combine to form protoplanets.
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What is the age of the oldest rock found on Earth?
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4 billion years old
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What era marks the final formation of the Rocky Mountains?
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Cenozoic era
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When did the supercontinent Pangaea form?
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250 million years ago
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What was the "Cambrian Explosion"?
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a sudden large increase in life forms, during which all major groups of invertebrates came into being
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What hypotheses have been proposed to explain the demise of the dinosaurs?
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-huge volcanic eruptions
-asteroid impact
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How did the Cretaceous-Paleogene extinction influence evolution?
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The demise of the dinosaurs led to diversification of mammals.
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When did dinosaurs go extinct?
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65 million years ago, at the Cretaceous-Paleogene boundary
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What best describes conditions on Earth during the Hadean?
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The surface was hot and molten. Nickel and iron mere melted by the heat and eventually settled into the core.
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How was free oxygen introduced in Earth's atmosphere?
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Bacteria released free oxygen as a by-product of photosynthesis.
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Which gas was added to the early atmosphere of the Earth by the outgassing of volcanoes?
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carbon dioxide
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How would low-density continental crust be produced from a mafic mantle?
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partial melting of mantle material
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Put the following events in the order they occurred to lead to the formation of the solar system:
A. Earth was bombarded by new materials after formation.
B. Earth separated into layers based on the weight of materials.
C. Hydrogen and helium formed atoms.
D. Outgassing of volcanoes produced a primitive ocean.
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C, A, B, D
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Hydrogen and Helium would have been the first elements to form after the Big Bang. How were heavier elements produced?
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the supernova of early stars
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Which processes created the magma ocean that used to exist on the planet Earth?
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-bombardment
-radioactive decay
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What processes created the Earth's moon?
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-Earth was struck by a large planetesimal
-Debris from Earth and another planetesimal accreted
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Which planet in the solar system had more mass accreted to it via a comet that impacted in 1994?
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Jupiter
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Which region of North America has the oldest parts of the continent?
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Northern Canada
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Which geologic event was responsible for adding the Grenville Province to North America approximately 1.2 billion years ago?
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formation of Rodinia
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What is responsible for creating stromatolites?
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cyanobacteria (blue-green bacteria)
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True or False: Prokaryotes did not have nuclei
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True
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Which animal are all tetrapods derived from?
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lobefin fish
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The Archaeopteryx is an early bird that came into existence at the time of the dinosaurs. It had a mix of reptilian and bird features. Of the physical features listed below, which are reptilian features?
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-wings
-feathers
-TEETH
-LONG TAIL
-WING CLAWS
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Mammals are derived from __________, which are derived from __________.
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reptiles; amphibians
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__________ were able to diversify after the extinction of the dinosaurs.
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Mammals
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What characteristics best separates humans from other mammals?
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-bipedalism
-upright posture
