The outer layer of the onion cell, which is a plant cell, contains cellulose, however, the human skin cell (which is an animal cell) does not contain cellulose in it. The plant cells have a rigid cell wall present around the cell membrane, which protects the cell from the outer environment and keeps it rigid. This cell wall of the plant cells is composed of the cellulose. The animal cells have no cell wall present around them, and thus, contain no cellulose.
Hence, the correct answer is 'it contains cellulose'.
