The temperature in deciduous forest can range from -30° C to 30°C with 10°C being an average temperature.
Wood frog has adapted to survive in freezing temperatures during winters. It does so by practicing thawing and freezing in a cyclic or systematic manner.
It helps the frog to accumulate glucose and urea in the body. These substances then act as cryoprotectant that is, they prevent the freezing of the cells or tissues (by lowering the freezing point) of the organism and thus prevent the loss of water from the cells.
On arrival of spring, the warm temperature thaws the frog after which the leftover glucose is converted back to glycogen and urea is excreted out of the body.
Wood frogs have this adaptation where they accumulate urea in their bodies and convert their liver glycogen to glucose to act as cryoprotectants. This prevents the formation of ice crystals in their bodies that could cause damage cells during freezing in winter.
