Bergman's rule states that

Options

A. Organisms of hotter areas are darkar in colour
B. Mammals and birds of hotter areas undergo aestivation in summer
C. Aquatic animals are larger as compared to terrestrial ones
D. Mammals and birds of colder areas are generally larger than those of hotter regions.

Answer

**Step-by-Step Text Solution:**

1. **Understanding Bergman's Rule**: Bergman's Rule is a principle in biology that was proposed by Carl Bergman. It relates to the size of warm-blooded animals (mammals and birds) and their adaptation to environmental temperatures.

2. **Adaptive Mechanism**: The rule is based on the idea that the size of these animals is an adaptive mechanism to conserve or radiate body heat depending on the climate. In colder regions, larger body sizes help in conserving heat, while smaller body sizes in warmer regions help in dissipating heat.

3. **Temperature and Body Size Correlation**: Bergman's Rule states that within a broadly distributed taxonomic group, populations and species of larger size are found in colder environments, while those of smaller size are found in warmer environments.

4. **Conclusion**: Therefore, the correct interpretation of Bergman's Rule is that mammals and birds of colder areas are generally larger than those of hotter regions.

5. **Final Answer**: The statement that best describes Bergman's Rule is: "Mammals and birds of colder areas are generally larger than those of hotter regions."

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