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.
â¢ It is present in prokaryotes and eukaryotes. â¢ Main functions of the plasma membrane: 1. Regulation of exchange with the environment. It is a selective barrier that regulates the flow of nutrients into the cell and discharge of wastes out of the cell. 2.