CBSE Class 9 Answered

Plasma membrane is a selectively permeable membrane of the cell which regulates the entry and exit of substances in the cell. It maintains homeostasis, i.e., constant internal composition of the cell. If the plasma membrane ruptures or breaks down, the constant internal composition of the cell will be lost and the cell will not be able to perform its basic functions. The intracellular contents will leak out and such a cell with ruptured plasma membrane would get killed.