Animal cells do not have cell walls. Cell membranes separate the cytoplasm of the animal cells from the surroundings and maintain their interior. Plant cells have cellulosic cell walls. A cell wall surrounds the cell membrane of a plant cell. Cell walls serve to provide structural support and protect plant cells from pathogens. Cell walls also help keep excess water out of cells so they do not burst. Therefore, human cheek cells would not have cell walls while the onion cells would have cell walls made up of cellulose.
Aristotle finds the good and noble man to be selfish. But from his virtue and righteous behavior emerge gifts that his friends, his homeland, and his own community benefit from. He is a committed person who looks down upon material wealth, but enjoys the benefits of honor and dignity.