The osmotic expansion of a cell kept in water is chiefly regulated by
| 1. | Mitochondria | 2. | Vacuoles |
| 3. | Plastids | 4. | Ribosomes |
Vacuole in a plant cell
| 1. | is membrane-bound and contains storage proteins and lipids |
| 2. | is membrane-bound and contains water and excretory substances |
| 3. | lacks membrane and contains air |
| 4. | lacks membrane and contains water and excretory substances |