The osmotic expansion of a cell kept in water is chiefly regulated by:
Mitrochondria
Vacuoles
Plastids
Ribosomes
As we discussed in concept
Vacuoles have single membraned tonoplast, acts as semipermeable membrane.
Option 1)
Mitrochondria
This option is incorrect.
Option 2)
Vacuoles
This option is correct.
Option 3)
Plastids
This option is incorrect.
Option 4)
Ribosomes
This option is incorrect.