SCIENCE
CELL BIOLOGY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Water absorbs heat when it evaporates and forms a gas
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Water expands and becomes less dense when it freezes
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Water molecules completely separate into ions in solutions
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Water forms hydrogen bonds with ions and other polar substances
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Detailed explanation-1: -Many fish and aquatic plants can survive a cold winter because the layer of ice that forms at the top of the lake insulates the water below and prevents the lake from freezing solid. What unique property of water contributes to this effect? Water expands and becomes less dense when it freezes.
Detailed explanation-2: -The high specific heat for water that covers most of the Earth keeps temperature fluctuations on land and in water within limits that permit life. Water’s high specific heat also helps regulate temperatures in organisms.
Detailed explanation-3: -One of the unique properties of water is that it becomes less dense as its temperature decreases from 4° C until it freezes at 0° C. This allows many aquatic life forms to survive through the winter. If ice were more dense than water, it would freeze and sink over and over until the entire lake was frozen.
Detailed explanation-4: -Water is less dense as a solid than as a liquid. This property is important, as it keeps ponds, lakes, and oceans from freezing solid and allows life to continue to thrive under the icy surface.
Detailed explanation-5: -Finally, the high specific heat of water makes it resistant to temperature change, allowing life forms to maintain relatively constant internal temperatures. The high specific heat and surface tension of water contribute to its high boiling point, helping to keep it in liquid form for most biological processes.