LIFE SCIENCE

Detailed explanation-1: -The plasma membrane, or the cell membrane, provides protection for a cell. It also provides a fixed environment inside the cell, and that membrane has several different functions. One is to transport nutrients into the cell and also to transport toxic substances out of the cell.

Detailed explanation-2: -The plasma membrane is the border between the interior and exterior of a cell. As such, it controls passage of various molecules-including sugars, amino acids, ions, and water-into and out of the cell.

Detailed explanation-3: -Because of the hydrophilic and hydrophobic regions of the phospholipid bilayer, small nonpolar molecules cross the membrane easily, while large and hydrophilic molecules cannot cross easily.