Under high ionic concentration in the water, osmosis tends to move water in which direction relative to the organism?

Under high ionic concentration in the water, osmosis tends to move water in which direction relative to the organism?

• A. Water moves into the animal.
• B. Water moves from the animal into the water.
• C. Temperature rises in the tank.
• D. Fatal toxins accumulate in the tank

Answer: (B)

When the surrounding water has a high ionic concentration, it becomes hypertonic relative to the animal’s body fluids. Osmosis moves water from areas of lower solute concentration to higher solute concentration. Since the animal’s internal fluids have a lower solute concentration than the surrounding water, water is driven out of the animal into the water. That’s why water tends to move from the animal to the water in this situation. If the environment were hypotonic, water would move into the organism. The other options don’t describe this osmotic flow.

When the surrounding water has a high ionic concentration, it becomes hypertonic relative to the animal’s body fluids. Osmosis moves water from areas of lower solute concentration to higher solute concentration. Since the animal’s internal fluids have a lower solute concentration than the surrounding water, water is driven out of the animal into the water. That’s why water tends to move from the animal to the water in this situation. If the environment were hypotonic, water would move into the organism. The other options don’t describe this osmotic flow.