Question

The rigid layer of nonliving material that surrounds the cell of plants and other organisms is called the _____.

Answer 1

For plant cells there is a cell membrane and a cell wall. For animal cells there is a cell membrane but no cell wall. Because it is rigid, I think it is most likely the cell wall, but if other organisms include animals, then it is the cell membrane. 

Answer 2

All cells have the lipid bi-layer cell wall and plant cells have a cell wall as well which provides rigidity to the cell structure.