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16 Cards in this Set
- Front
- Back
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The constant movement of water as a liquid and a gas between Earth's air and its surface is the ________ ______ . The energy for the water cycle comes from the _________ . |
water cycle, sun |
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Solar energy causes water on Earth's surface to change to gas and rise into the atmosphere during the process of ______________ . |
evaporation |
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As gaseous water rises and cools, it turns into droplets of liquid water during the process of _______________ . |
condensation |
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Water droplets may fall from the atmosphere back to Earth's surface as _______________ , such as rain and snow. |
precipitation |
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Some water soaks into the ground and collects in pores in soil and rock to become __________ _________ . |
ground water |
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Plants take water from the soil and return it to the air through their leaves during ______________ . |
transpiration |
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The constant exchange of carbon on Earth is the ___________ __________ . |
carbon cycle |
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During photosynthesis, plants take ___________ __________ from the air and use it to make food that other living things use . |
carbon dioxide |
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Animals and plants burn carbon rich foods during cellular ______________ , and then release carbon dioxide to the atmosphere. |
respiration |
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The exchange of oxygen and carbon dioxide among different living things during respiration and photosynthesis is called the ___________ ________ ________ cycle . |
oxygen carbon dioxide |
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Although most of Earth's atmosphere is nitrogen , the gas must first be _______ so that it is in a form that most living things can use . |
fixed |
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Nitrogen can be fixed by volcanic action, by ___________ , and by nitrogen fixing __________ . |
lightning, bacteria |
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Plants use nitrogen to make _________ , which get into the bodies of animals when they eat plants or plant eating animals. |
proteins |
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Nitrogen returns to the soil in the _________ of animals, and when plants and animals decay. |
waste |
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People can reduce their use of natural resources through ____________ . |
recycling |
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Critical Thinking Why is it necessary for water , carbon, nitrogen, and oxygen to be recycled through Earth's ecosystem? |
Thes substances , which are necessary for all living things , would be used up and become unavailable if Earth's systems did not recycle them. |
