Adaptations-. Black bears have a thick layer of fur for the cold winters,claws to climb trees and stay away from danger along with sharp teeth for protection like scaring away predators and to tear apart fish.Bears also hibernate in the winter to avoid having to find food which is difficult in the winter.
The cell membrane, or plasma membrane, surrounds and protects the internal environment of a cell; however, this is not its only function. A cell membrane also determines what materials enter or leave the cell. This ensures that the cells will be able to get rid of wastes and take up important nutrients and gases.
The plasma membrane is like the skin of the cell and lets only certain things in and out. It uses active and passive transport to let things in and out meaning that it uses energy only sometimes to let things in and out (this being active) and lets things move as they please at other time (this being passive).