What is a similarity in function between the cell membrane and the cell wall?

cell membrane and cell wall both ward off unwanted bacteria or substances to come into the cell or what should come into the cell.

Answer: Both play protective function

Explanation:

The cell wall is exclusive to plant cell, unlike cell membrane that is present in both.

However, both cell wall and cell membrane are similar in that both provide protection and mechanical support for the cell against foreign invaders such as pathogens.