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 cell’s shape.
○ it prevents harmful substances from entering a cell.

Explanation:

• Analyze each option:
• Option 1: Cellulose is in plant cell walls, not cell membranes. So this is false.
• Option 2: Cell membranes are present in both animal and plant cells (plant cells have cell walls too, but still have cell membranes). So this is false.
• Option 3: The rigid structure for cell shape in plant cells is the cell wall, not the cell membrane (cell membrane is flexible). So this is false.
• Option 4: The cell membrane is selectively permeable and prevents many harmful substances from entering the cell. This is true.

Answer:

It prevents harmful substances from entering a cell.