Why do you think plant cells have cell wall as well as a cell membrane
Answers
they don't move
so for:
+protection
+rigidity
+postural stability
The main reason behind that plants cells have cell was is that they cannot move and protect themselves. So that they have cell wall which gives them strength and rigidity so that they can fight outer bodies. It gives them shape. It also acts as a barrier for foreign bodies to enter. However, anyhow if any foreign body enters into plants cells they get digested by Lysosome. Actually, Lysosome is also called as sucidal bag of the Cells.
They also have cell membrane. This is because Cell membrane or Plasma Membrane transfer other elements to the cell organelles.
Some other Information :-
Do you know why Mitochondria is called as Semi-autonomous organelle?
The main reason behind this is Mitochondria is the only organelles that can prepare enery in the form of ATP (Adonsine Triphosphate). So that this also called Power house of the cell.