Here's why:

* Chloroplasts: Grass cells contain chloroplasts, which are organelles responsible for photosynthesis. Animal cells do not have chloroplasts.

* Cell Wall: Grass cells have a rigid cell wall made of cellulose that provides structure and support. Animal cells lack a cell wall.

* Large Central Vacuole: Grass cells have a large central vacuole that helps regulate water balance and provides storage space. While animal cells do have vacuoles, they are much smaller.