What is a key difference between plant and animal cells?

The key difference highlighted in the correct answer is the presence of a cellulose cell wall in plant cells, which is not found in animal cells. This cell wall provides structural support and rigidity to plant cells, allowing them to maintain shape and integrity, especially in the face of osmotic pressure. The cell wall is primarily composed of cellulose, a polysaccharide that adds strength.

In contrast, animal cells are surrounded by a flexible plasma membrane that does not have this rigid cell wall structure. This allows animal cells to be more variable in shape and size and enables them to move more freely and change their forms. The absence of a cell wall in animal cells is essential for processes such as muscle contraction and cell migration.

Understanding this fundamental distinction helps clarify various biological processes and structural differences in organisms, as plants and animals have adapted to their environments in ways that reflect these cellular differences.