1. The problem statement, all variables and given/known data A protozoa that normally lives in the ocean is placed in a freshwater fish tank. What would happen to the water balance in the cell? Use the terms osmosis, turgor, cell membrane, hypertonic or hypotonic. Describe what could happen to this cell (remember to include any cellular organelles that could help the cell out.) 2. Relevant equations None 3. The attempt at a solution I know that because the protozoa was in ocean water, there would be salt solute in the cell. Through osmosis, the diffusion of water molecules (solvent) would occur through the differentially permeable cell membrane. The cell membrane would allow the fresh water to rush into the cell, and some of the salt molecules to flow it, creating a balance both inside and outside the cell. Due to the salt solute going out of the cell, and the fresh water molecules going in, I believe that it would be a hypotonic solution with a lower concentration of solute (higher concentration of water) outside the cell than inside, because the net flow of water is into the cell. The cell would be turgid, because the fresh water would make the cell more full, and rectify any shrinkage that occurred because of the salt. The contractile vacuole is the cell organelle that could help it out, because it could expel water if the cell becomes too bloated and pops.