Here's why:
* Cell wall: This rigid outer layer provides support and structure to the plant cell. It is primarily made of cellulose, a complex carbohydrate. Animal cells lack cell walls.
Let's look at the other options:
* Cell membrane: This is a thin, flexible layer that surrounds all cells (both plant and animal), regulating what enters and leaves the cell.
* Nucleus: This is the control center of the cell containing genetic material (DNA). It is present in both plant and animal cells.
* Cytoplasm: This is the gel-like substance that fills the cell and contains all the organelles. It is present in both plant and animal cells.
Therefore, the cell wall is the only structure that is unique to plant cells.
