Question

In a region with a cold climate, the aquatic plants and animals can survive even when the atmospheric temperature goes below 0 degrees Celsius. Comment on the above statement.

Answer 1

Hint: The anomalous expansion of water helps preserve aquatic life during very cold weather. When the temperature falls, the top layer of water in a pond contract becomes denser and sinks to the bottom. As we know ice is a bad conductor of heat.

Complete step by step answer:Water has a peculiarity property according to which it has maximum density at around 4 degrees Celsius. As we go above or below the mark, the density decreases. Also, the density of ice is lower than that of water. A circulation is thus set up until water in the pond reaches it is the maximum density of 4 degrees Celsius.
When at atmospheric temperature reaches 0 degrees Celsius ice begins to form in ponds forming a layer on the top with water below it. If water did not have this property, then it would be impossible for aquatic life to exist in water bodies in cold seasons.
After sufficient thickness of ice is formed it prevents further loss of heat from the bottom layers of water. This is why fishes and other aquatic animals and plants can survive in ponds and other water bodies even when the atmospheric temperature reaches or is well below 0 degrees.

Note:If the temperature falls further, then the top layer expands and remains on the top till it freezes. In cold countries, the temperature of the water body decreases as a result of which ice is formed at the top. Above the water body bed (a constant supplier of heat) is the 4 degrees Celsius comparatively denser water maintained at that particular temperature due to the same heat source.