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10 Cards in this Set
- Front
- Back
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fossil
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Any naturally preserved evidence of life
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mold
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An impression of an organism formed when sediments harden around the organism
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cast
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A model of an organism formed when sediment fills a mold and hardens
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fossil fuel
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An energy-rich resource formed from the buried remains of once-living organisms
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index fossil
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A fossil of a type of organism that lived in many places during a relativeely short time span
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mass extinction
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A period in which a large number of species become extinct
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What are the steps necessary for a fossil cast to form?
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1). An organism is buried in sediment which hardens around it, forming a mold. 2). The organism decays and the mold is left empty. 3). Sediment fills the mold and hardens, forming a cast.
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What is a possible sequence of events that might take place when a land organism dies?
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1). Scavengers might come and consume the organism's soft tissues. 2). it's hard tissues would be weathered by wind and rain. 3). In time they would completely decay.
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Explain the sequence of steps by which coal forms.
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1). Swamp plants die and sink to bottom of swamp. 2). They are decomposed by bacteria and fungi. 3). They are buried under more layers of decomposing plants. 4). They are finally changed to coal.
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What can fossils reveal about Earth's history?
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Fossils can help scientists determine the ages of rock layers and can show how Earth's surface has changed.
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