* Cell walls are rigid structures found outside the cell membrane of plant cells, bacteria, fungi, and some protists. They provide structural support and protection.

* Animal cells, on the other hand, have a flexible cell membrane that provides a barrier between the cell's internal environment and its surroundings.

Instead of a cell wall, animal cells have other structures that provide support and protection, such as:

* Cytoskeleton: A network of protein filaments that provides shape and support to the cell.

* Extracellular matrix (ECM): A complex network of proteins and carbohydrates that surrounds animal cells and helps them adhere to each other and form tissues.