Question

which statement about the cell membrane is true?
it contains cellulose and sugars that are involved in communication.
it is present in animal cells only.
it is rigid and elastic for supporting the cells shape.
it prevents harmful substances from entering a cell.

Explanation:

Cell membrane is a selectively - permeable barrier. It regulates the movement of substances in and out of the cell, preventing harmful substances from entering while allowing essential nutrients and molecules to pass through. Cellulose is in plant cell walls, not cell membranes. Cell membranes are in both animal and plant cells. They are fluid rather than rigid for support; cell walls provide rigidity in plant cells.

Answer:

It prevents harmful substances from entering a cell.