To complete the , you need to understand three primary states of tonicity:

In a hypotonic environment (freshwater), the vacuole must pump water out constantly to prevent the organism from exploding. How to Use Answer Keys Responsibly

: The diffusion of a solvent (usually water) across a semipermeable membrane from an area of high solvent concentration to low.

Note: Since I cannot distribute copyrighted material, these are the expected scientific answers based on standard Gizmo builds (A/B).

The answer lies in the solute.