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9 Cards in this Set
- Front
- Back
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Most declines in populations is caused by ________.
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humans
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Natural events that causes changes in populations are usually _______.
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temporary
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Name a natural event that might affect a population of organisms.
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floods, fires or droughts
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When an organism becomes ___, its kind are no longer found on Earth.
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extinct
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Why do more organisms become extinct on island and not large continents?
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The island is usually not large enough for organisms to spread out and avoid problems that cause extinction.
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Animals that are _____ are in danger of become extinct if steps aren't taken to save the population.
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endangered
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Animals that are _____ are threatened with becoming endangered if steps are taken to save the population.
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threatened
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Name one animal that was on the endangered list in the 60s that is doing well now.
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bald eagles
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What poison used as an insectcide was responsible for the decline in several bird species?
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DDT
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