Although this question may seem like a multipart question yo
Solution
German biologist Christian Bergmann, proposed that animal which are living at higher latitudes will be growing larger when compared to the same animals which are living at warmer, lower altitude. This is known as Bergmann\'s Rule.
The hypothesis proposed for this is, animals living in cold climate will be larger, thus they will have lower surface to body mass in comparison with smaller animals, and thus these larger animals can retain heat better. But whereas the animals living in warm climate, will release the heat quickly generated due to metabolism to keep their body cool. Thus animals living in warmer climate will have higher surface area to volume ratio. So, animals based on the altitude and climate, they have changed their body size to adapt to those conditions. Another reason they say plants available in colder climate are more nutritious than warmer climate.
