Final answer:
Aquatic life in deep lakes becomes dormant during winter as the surface freezes and forms an insulating layer, preserving a liquid environment below where organisms can survive.
Step-by-step explanation:
During winter, aquatic life experiences challenges due to the freezing temperatures. The correct answer to what happens to aquatic life in deep lakes when water freezes during winter months is c) Aquatic life becomes dormant. As temperatures drop, lakes begin to freeze, starting from the top since ice is less dense than liquid water. This forms an insulating layer on the surface, which helps to maintain the water below at a survivable temperature for aquatic life. While a layer of ice forms, lakes do not freeze solid because water is densest at about 4°C; below this temperature, water expands and becomes less dense. This keeps the water in a liquid state beneath the layer of ice.
Aquatic life adjusts by either becoming dormant or by reducing activity to conserve energy. They utilize the oxygen and nutrients available to them in the deeper, liquid water to survive during the icy months. Consequently, aquatic organisms like fish can live through the winter underneath the ice layer.