Two major structural differences between cells from kingdoms plantae and animalia; PLANT CELL wall, primarily composed of cellulose, is what provides the whole plant structure support and rigidity. Animal cells do not have a cell wall, which typically distinguishes them from other The primary function of plant cells is to carry out photosynthesis because of the presence of chlorophyll in their chlorophyll. Animal cells are unable to synthesize their own food, hence are always dependent on plants.