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31 Cards in this Set
- Front
- Back
How do animals get the materials they need?
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by eating or drinking
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How do plants get the materials they need?
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from the soil and air
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All living things need ___.
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nitrogen
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_________ makes protein in both plants and animals.
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nitrogen
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The Earth's atmosphere is about ___% nitrogen.
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78%
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Nitrogen in its natural state is a _____.
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gas
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In the __ ____ nitrogen is changed from a gas into a form plants can use.
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nitrogen cycle
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The usable forms of nitrogen are ___ and ____.
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nitrates and ammonia
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The word "fixed" means to ____ in this chapter.
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to change
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Two ways nitrogen is "fixed" in the soil are:
1 2 |
1)bacteria in the soil, and
2)nodules on the roots of a plant |
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A small amount of nitrogen is "fixed" by _______.
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lightening
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Nitrates and ammonia are returned to the soil by:
1 2 |
1)animal waste, and
2)decaying plants and animals |
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What two processes have kept the carbon dioxide -oxygen cycle in balance?
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1)photosynthesis and
2)cellular respiration |
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The ___ _____ caused the amount of carbon dioxide in the atmosphere to increase.
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Industrial Revolution
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Seas, oceans, lakes and rivers make up about ___% of the Earth's surface.
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75%
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What percent of the Earth's carbon is found in oceans?
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71%
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The movement of water from the atmosphere to the earth and back is known as the __ __.
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water cycle
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The process of water changing into a water vapor is _____.
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evaporation
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The process of water vapor changing into a liquid water is ____.
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condensation
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Any form of water that falls from clouds is called ___.
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precipitation
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About ___% of the human body is water.
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70%
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Plants give off water from their stomata in a process called ____.
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transpiration
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Animals give off water from their _____ when they exhale.
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lungs
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Name the four processes of the water cycle: 1 2 3 4
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1) evaporation
2) condensation 3) precipitation 4) transpiration |
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Less than ___% of the Earth's fresh water is usable because most of its frozen in ice caps and glaciers.
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1%
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How does human activity affect the amount of usable fresh water?
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Rainwater running off land picks up harmful chemicals and carries them deep into the soil.
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Name two human activities that increase the amount of carbon dioxide in the atmosphere? 1 2
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1) burning fossil fuels
2) cutting down trees |
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Where is most of the fresh water on earth?
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glaciers and ice caps
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Fossil fuels contain most ___.
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carbon
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Warm temperatures cause water to change from a ____ to a _________.
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liquid to a gas
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Cold temperatures cause water to change from a ____ to a _______.
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gas to a liquid
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