Answer:
The selectively permeable membrane is important because it will allow only those materials and ions to pass which are required by a cell. The selectively permeable cell membrane is important to maintain the homeostatic conditions for a cell. It actively maintains the internal cell environment.
If cell membrane was not permeable then toxic molecules and ions as well as waste elements would enter the cell destroying the cell. An increase in the amount of ions in the cell might have caused the cell to burst.
