What is Biome?
A biome is a large geographical area of distinctive plant and animal groups, which are adapted to that particular environment. The climate and geography of a region determines what type of biome can exist in that region.
This is my popplet of Tundra:

The tundra is a very fragile environment.
The extremely cold temperatures makes it a difficult environment to survive in during the winter, and plants and animals have a hard time coping with any extra stresses and disturbances.
This is th popplet of Desert:
http://popplet.com/app/index.php#/281575
A desert is a landscape or region that receives an extremely low amount of precipiation , less than enough to support growth of most plants. Most deserts have an average annual precipitation of less than 400 millimetres
http://popplet.com/app/index.php#/353586
A population is all the organisms that both belong to the same group or species and live in the same geographical area.
This is the Popplet of Migration:http://popplet.com/app/index.php#/405610
Migration is the movement by humans from one area to another