20%

10%

30%

50%

Cold

Barren

Lots and lots

Treeless plain

The cold causes fur to change colors

The changing fur has no real purpose

The animals try to keep up with the newest styles

Shedding one color coat for another helps them stay camouflaged in most seasons

Permanent frost

Soil that stays frozen for two or more years

Any frozen soil

What happens to plants when they freeze

Special bones in their nose that help them save water

All of the above

Dense fat, with thick fur that covers all external surfaces

Keeping their extremities relatively cold