Question

The tonoplast is

• A. Impermeable
• B. Semi-permeable
• C. Differentially permeable
• D. None of the above
  

Answer 1

Answer: (C)

Differentially permeable

A membrane allowing both solutes and solvent molecules to freely pass through is called as permeable. A membrane not allowing any solute or solvent molecule to pass through is called as impermeable. A membrane which allows only solvent molecules but no solute molecule to directly pass through it is called as a semi-permeable membrane.

The membrane of tonoplast allows water, i.e., solvent and selected solute molecules to freely pass through it. Hence, it is called as differentially permeable membrane.