How does a human end up with an extra chromosome?

Which would be an adaptation in a rainforest, but not in a tundra? a. ability to store water for a long time b. fur that blends in with snow c. strong claws for killing prey d. a beak that can dig into thick trees

In the practice of science, this type of reasoning is used to develop explanations.

What are two examples of conduction that we use everyday