4. Cell wall and Cytoplasm

In addition to the cell membranes, the plant cells contain a thick outer layer known as the cell wall. The cell wall surrounding the cell membrane protects the plants from variations in temperature, high wind speed, atmospheric moisture etc., by preventing them from moving. Unlike plant cells, animals lack cell walls.

 

Plant cell wall      

 

 

The cell wall serves as a structural framework for the plant and bacterial cells. In plant cells, the cell wall is made up of a non-living substance known as cellulose. Cellulose helps maintain the shape of the plant cell and makes the cell rigid and upright even when it grows in height.