Having an equal solute concentration inside and outside the cell. Ideal (perfect) conditions. Cell remains normal.

Having an equal solute concentration inside and outside the cell. Ideal (perfect) conditions. Cell remains normal.

• A. Hypertonic
• B. Hypotonic
• C. Isotonic
• D. Equilibrium

Answer: (C)

Tonicity and osmosis are the key ideas here. When the solute concentration is the same inside and outside the cell, there is no net movement of water across the membrane because the water potential is balanced on both sides. That situation is described as isotonic. Under isotonic conditions, the cell’s volume remains stable and its shape stays normal because water is moving in and out at equal rates. If the outside solution had more solute (hypertonic), water would leave the cell and the cell would shrink. If the outside solution had less solute (hypotonic), water would enter the cell and it could swell or burst. Equilibrium is a general idea of balance, but the standard term for equal solute concentrations across the membrane is isotonic.

Tonicity and osmosis are the key ideas here. When the solute concentration is the same inside and outside the cell, there is no net movement of water across the membrane because the water potential is balanced on both sides. That situation is described as isotonic. Under isotonic conditions, the cell’s volume remains stable and its shape stays normal because water is moving in and out at equal rates.

If the outside solution had more solute (hypertonic), water would leave the cell and the cell would shrink. If the outside solution had less solute (hypotonic), water would enter the cell and it could swell or burst. Equilibrium is a general idea of balance, but the standard term for equal solute concentrations across the membrane is isotonic.