Question

scenario 7: a saltwater fish struggles after being put in a freshwater tank. q1. tonicity of the solution? q2. how do the cells respond? q3. what question could you ask to confirm?

Explanation:

Q1

Saltwater fish have cells adapted to high - salt (hypertonic) environment. Freshwater is a hypotonic solution (lower solute concentration, higher water concentration) relative to the fish's cells.

In a hypotonic solution, water moves into the fish's cells (by osmosis, as water moves from an area of higher water potential - freshwater - to lower water potential - inside the fish's cells which have higher solute concentration). This causes the cells to swell, and if the influx of water is too much, the cells may even burst, which is why the fish struggles.

To confirm the tonicity and the osmotic effect, we can ask about the solute concentration inside and outside the fish's cells or about the direction of water movement. For example, asking about the concentration of salts in the freshwater tank compared to the fish's internal environment, or if the fish's cells are gaining or losing water, or what would happen if the fish is put back into saltwater. A suitable question could be: "What would happen if we put the fish back into saltwater?" or "Is the concentration of dissolved salts in the freshwater lower than in the fish's cells?"

Answer:

The solution (freshwater tank) is hypotonic.

Q2