How do polar bears maintain homeostasis in freezing cold weather?
• Their thick fur retains heat.
• Their metabolism slows down to preserve heat.
• Their metabolism speeds up to produce heat.
• Their thick skin insulates the internal organs against the cold
All of the given options are correct ways in which polar bears maintain homeostasis in freezing cold weather. Here is a brief explanation of each:
1. Their thick fur retains heat: Polar bears have a dense layer of fur that helps to trap heat close to their body. The fur acts as insulation, preventing the loss of body heat to the cold environment.
2. Their metabolism slows down to preserve heat: In extreme cold, polar bears have the ability to slow down their metabolism. This reduces the rate at which they burn energy and helps to conserve heat. By slowing down their metabolic rate, polar bears can maintain their body temperature in extremely cold conditions for extended periods of time without needing to eat as frequently.
3. Their metabolism speeds up to produce heat: On the other hand, when polar bears need to generate more heat in order to stay warm, such as when they are actively hunting or swimming in cold waters, their metabolism speeds up. The increased metabolic activity helps to generate heat, thus keeping them warm.
4. Their thick skin insulates the internal organs against the cold: In addition to their thick fur, polar bears have a layer of fat beneath their skin, called blubber. This layer of blubber acts as insulation, preventing the cold from reaching the bear's internal organs. It provides an additional barrier against the freezing temperatures and helps to maintain a stable body temperature.
Overall, these adaptations allow polar bears to survive and thrive in their icy habitats by maintaining homeostasis despite the freezing cold weather.