A) have occurred at least 5 times in the Earth's history.
B) may have been due to climatic changes after meteorite collisions.
C) may have been due to changing environments caused by continental drift.
D) All of the choices are correct.
F) B) and C)
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A) an enzyme or reaction capable of removing one oxygen from ribose in nucleotides
B) enzymes for reverse transcription of RNA into DNA
C) new enzymes to replicate the DNA
D) new enzymes for transcribing DNA back to RNA
E) All would be necessary to switch to a "DNA world."
G) B) and E)
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B) False
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A) subduction zone.
B) transform boundary.
C) oceanic ridge.
D) supercontinent.
F) B) and D)
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A) 1.5
B) 2.0
C) 3.5
D) 4.5
F) A) and D)
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A) The Precambrian experienced 0, Paleozoic experienced 3, Mesozoic experienced 2 and the Cretaceous experienced 0 mass extinctions.
B) The Precambrian experienced 2, Paleozoic experienced 2, Mesozoic experienced 3 and the Cretaceous experienced 0 mass extinctions.
C) The Precambrian experienced 0, Paleozoic experienced 2, Mesozoic experienced 3 and the Cretaceous experienced 0 mass extinctions.
D) The Precambrian experienced 1, Paleozoic experienced 3, Mesozoic experienced 2 and the Cretaceous experienced 1 mass extinctions.
F) A) and D)
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Plate tectonics theory maintains that the Earth's outermost layers are fragmented into slablike plates that are less dense, and therefore "float" on the lower hot mantle layer. Both continents and oceans are part of these tectonic plates. As the molten mantle heats and cools, rising and sinking, it moves like a conveyor belt, moving the tectonic plates slowly across the surface of the Earth. Some plates move apart, while others scrape past each other or crash into one another. The plates are still moving, slowly but continually around the Earth. One must remember that life evolved in the oceans and on the continents that are part of these "moving" tectonic plates. Very simply, this means that the Earth's environment was and is always changing. At one time, Australia was near the South Pole, as was India. There was no Atlantic Ocean, and South America and Africa were joined. Organisms adapt to changing environments, and the theory of plate tectonics provides for the ever changing environment in which evolution occurs. Knowing that supercontinents have existed, followed by isolated or partially joined land masses helps to explain the distribution patterns of fossils and the interesting distribution of living organisms on Earth today.
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A) the coastlines of several continents are mirror images.
B) similar geological structures are found in areas where the continents touched.
C) continental drift has ceased.
D) the unique distribution patterns of several fossils is explained by continental drift.
F) A) and C)
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A) was much thinner around the surface of the Earth than now.
B) contained only two or three kinds of gases.
C) contained little or no free oxygen.
D) contained little or no free nitrogen.
E) contained little or no carbon dioxide.
G) A) and D)
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A) Mitochondria and chloroplast are the same size as bacteria.
B) Mitochondria and chloroplast divide by binary fission.
C) Mitochondria and chloroplast both contain DNA and some can make their own proteins.
D) The outer membrane of chloroplast and mitochondria resemble that of a eukaryotic cell while the inner membrane resembles that of a bacterial cell.
E) All of these are correct.
G) A) and E)
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D
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A) the RNA-first hypothesis is impossible.
B) RNA could not have arisen on its own by chance, but required enzymes to guide the synthesis of nucleotides and then nucleic acids.
C) sophisticated enzymes were not present or available to synthesize it.
D) no natural system could ever generate it.
E) the protein-first hypothesis is therefore the only plausible hypothesis.
G) None of the above
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A) mammals greatly diversified during this time.
B) multicellular organisms first evolved during this time.
C) this is the time period most studied.
D) hard body parts evolved in plants and animals.
F) A) and B)
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D
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Answers may vary a bit but should includ...View Answer
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A) It is supported by the discovery that RNA can act as an enzyme.
B) It is supported by the fact that some viruses have RNA as their genetic material.
C) It suggests that there was an "RNA world" about 4 billion years ago.
D) It says that first RNA, then DNA, and then proteins would have been necessary to interact in the chemical evolution that would have led to the development of the first cells.
F) B) and C)
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A) Stanley Miller
B) Graham Cairns-Smith
C) Thomas Cech
D) Aleksander Oparin
E) Sidney Fox
G) A) and C)
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A) proteinoid.
B) polymer.
C) microsphere.
D) coacervate.
E) liposome.
G) A) and B)
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A) During the Paleozoic Era three mass extinctions occurred which led to the colonization of land by plants while during the Mesozoic Era gymnosperms became the dominant plant life.
B) During the Mesozoic Era three mass extinctions occurred which led to the colonization of land by plants while during the Paleozoic Era gymnosperms became the dominant plant life.
C) During the Paleozoic Era five mass extinctions occurred which led to the colonization of land by plants while during the Mesozoic Era angiosperms became the dominant plant life.
D) During the Mesozoic Era five mass extinctions occurred which led to the colonization of land by plants while during the Paleozoic Era angiosperms became the dominant plant life.
F) C) and D)
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B) False
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B) False
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