Final answer:
Lipids, including body fat and cholesterol, are essential for heat conservation in animals, providing insulation against the cold and maintaining cell membrane fluidity across temperature variations.
Step-by-step explanation:
Lipids play a crucial role in heat conservation in animals. In cold environments, animals such as polar bears and seals rely on a thick layer of body fat for insulation against the cold. The fat acts as a barrier, reducing heat flow from the warm body to the cold environment. This physical property of body fat is essential for maintaining a constant and warm body temperature, especially in subfreezing conditions.
Furthermore, another lipid, cholesterol, is found in cell membranes and helps to maintain fluidity across a range of temperatures. It acts as a buffer, preventing the cell membrane from becoming too rigid in cold temperatures or too fluid in warm temperatures.
Overall, lipids are fundamental to an animal's ability to survive in extreme climates by helping to maintain body heat and ensure that cellular functions can operate normally regardless of external temperature changes.