animals with a constant body temperature such as mammals and birds require more food than do animals with a • changing body temperature such as reptiles and fish. Why?

Options

A. Much of the food is utilised to produce heat to keep warm
B. Warm-blooded animals waste more food than cold-blooded animal
C. Cold-blooded animals digest their food more efficiently than warm-blooded animals
D. None

Answer

**Step-by-Step Solution:**

1. **Understanding Body Temperature Regulation:**
- Animals can be classified based on their ability to regulate body temperature. Mammals and birds are known as warm-blooded (endothermic) animals, while reptiles and fish are considered cold-blooded (ectothermic) animals.

2. **Energy Requirements:**
- Warm-blooded animals maintain a constant body temperature regardless of the external environment. This requires a significant amount of energy, which they obtain from food.

3. **Heat Production:**
- To keep their body temperature constant, warm-blooded animals generate heat through metabolic processes. This heat production is essential, especially in cooler environments, where they need to expend more energy to maintain their body temperature.

4. **Food Utilization:**
- A large portion of the food consumed by warm-blooded animals is utilized for energy production to generate heat. This is why they require more food compared to cold-blooded animals.

5. **Efficiency of Digestion:**
- Cold-blooded animals, on the other hand, do not need to expend as much energy to maintain their body temperature since their body temperature fluctuates with the environment. As a result, they can digest food more efficiently and require less food overall.

6. **Conclusion:**
- In summary, warm-blooded animals require more food than cold-blooded animals primarily because they need to generate heat to maintain a constant body temperature, which requires more energy derived from food.

---