All of the above
Keeping their extremities relatively cold
Dense fat, with thick fur that covers all external surfaces
Special bones in their nose that help them save water
Lots and lots
Cold
Barren
Treeless plain
The animals try to keep up with the newest styles
The cold causes fur to change colors
Shedding one color coat for another helps them stay camouflaged in most seasons
The changing fur has no real purpose
Tundra can be found on the tops of some mountains.
Some plants of the tundra can perform photosynthesis at lower than normal light levels.
50%
10%
20%
30%
Permanent frost
Any frozen soil
What happens to plants when they freeze
Soil that stays frozen for two or more years