Biology · CELL THE UNIT OF LIFE

In plant cells, the tonoplast plays a crucial physiological role by facilitating the transport of a number of ions and other materials. What is the direction and nature of this transport relative to concentration gradients?

1. A
   Along concentration gradient into the cytoplasm, depleting vacuolar mineral reserve
2. B
   Against concentration gradient into the vacuole, making vacuolar concentration significantly higher than in cytoplasm
3. C
   Equally in both directions via simple passive diffusion until isotonic equilibrium is reached
4. D
   Against concentration gradient out of the vacuole into the cell wall apoplast