Question

Primary functions of plasma membrane

Answer 1

# it provides an outer boundary to the cell and protects it from injury
#it controls the substances that are allowed to enter and exit the cell
#it allows the flow of materials and information between the organelles of the same cell , as well as adjacent cells

Answer 2

1) it protects the cell from its external environment.

2) regulates the movement of substances in and out of cell.

Hope it helps. ;-)