Adaptations of animals to live in cold environments
- Hibernating is a behavioral response by many temperate and artic animals to very cold temperatures. The animal responds to a very cold temperature by going into a deep sleep. The metabolic rate falls to the minimum required to keep life ticking over. The body temperature also falls, and is maintained at a much lower level than normal. Hibernation saves these animals from expending large heat energy in winter whilst the food is scarce surviving extremes of temperatures.
- By supercooling: Supercooling is the lowering of the temperature of a fluid to below its freezing point without the formation of ice. Ice crystals can damage tissues and supercooling provides a way of avoiding this. Experiments have shown that certain reptiles can be supercooled to as low as -80C without freezing. Plants and fishes also go in for supercooling.
- By freezing tolerance. Some organisms, notably plants and insects can tolerate the formation of ice in their tissues. Certain insects’ larvae can recover after as much as 90% of the body has been frozen. In these organism’s ice crystals form between, rather than inside the cells; later when the ice melts. In some species of fish ice damage is lessened by the presence of glycerol in the tissues. Glycerol is used in human blood banks and sperm banks to prevent injury to the cells when they are frozen for storage.
- By using an antifreeze: some fish employ anti-freeze such as glycerol and glycoproteins to lowers the freezing point so that the body fluids do not freeze in winter.
CATEGORIES General
TAGS Dr. Bbosa Science
