What is the difference between the arctic and equator environment?

What is the difference between the arctic and equator environment? In the Arctic environment there is snow so the environment is cold while there is dirt or sand in the equator environment, so it is hot.

Explanation:

the cladogram shown here shows similarities and differences among several classes of vertebrates. anatomically, the four have limb structure as their common ancestor. we might separate the mammals from the other three classes because they a) divergent; do not lay eggs b) identical; are warm-blooded c) varied; a four chambered heart d) homologous; have mammary glands