An animals structure is very strong and doesn't need a cell wall or a central vacuole. This is because an animals body has a skeleton or something else that is supporting the structure.
In contrast, plant cells have a cell wall made of cellulose, which provides structure and support to the plant cell. Plants also have a central vacuole that helps maintain turgor pressure, which gives the plant structure and rigidity. Animals do not have these structures because they have evolved other ways to provide support and structure to their bodies.
