This document provides information about the cell wall and nucleus. It discusses that plant, fungi, and bacteria cells have a cell wall in addition to the plasma membrane that is made of cellulose and provides structural strength. The cell wall prevents bursting when the cell is in a hypotonic solution and allows plants to withstand variations in nature. The nucleus is surrounded by a double nuclear membrane and contains nucleoplasm and chromatin. It directs protein synthesis and is the control center of the cell.