Question

In higher latitudes where lakes freeze over in winter, how do cool autumn tempe]ratures help fish make it through the winter?

A-The cooling water slows fish metabolisms down and allows them to go into hibernation in winter.

B-Water from the bottom of the lake raises and provides oxygen to the cooler waters on the surface.

C- Cool water at the surface traps nutrients deep in the lake to provide food during the winter.

D-The water in contact with the air sinks and mixes with the less oxygenated water in the deeper levels.

Answer 1

My answer will be that water is a strange substance because its density decreases when the temperature drops to 4º C.

As the temperature of the water falls below 4ºC, what happens is that the density of this decreases. With this, the layer of water exposed to the atmosphere has a lower density than the bottom layer. The top layer freezes before the bottom one, giving the opportunity for water in the bottom to remain liquid. This is how aquatic life survives.

In other words, the survival of life is proportional to the depth of the lake: thus, in a puddle it is impossible to have life in the lower layer of water, while in a large lake it is possible.

Answer 2

C- Cool water at the surface traps nutrients deep in the lake to provide food during the winter.

Step-by-step explanation:

• As the fish have the ability to adapt to the changing temperature and they are generally are cold-blooded animals and the colder temperatures mean a reduction in the metabolic rates of the fish and this slow the numerous process of the digestion, feeding activity and thus they are often classified as cold, warm freshwater species.

• Atmospheric oxygen is needed for them to survive in the cold and they feed on the planktons and take the nutrients and the minerals from the surface of the and there don't remain so active as the period of the summer and the spring months.