The three functional regions of cell are :
1. cell membrane :
Every cell is covered with a thin sheet of skin which is called cell membrane or plasma membrane which controls the movement of the substances " into the cell " and "out of the cell".
2. Cytoplasm :
cytoplasm is the transparent jelly like material which fills the cell between nucleus and cell membrane.
most of the chemical reactions which keep the cell alive takes places here.
3. Nucleus :
It is a large, spherical organelle present in all the cells. It controls the activities of the cell.