A unicellular organism is living in freshwater. Water that moves into the cell cytoplasm by osmosis is gathered in a structure known as the contractile vacuole. To expel the water, the contractile vacuole joins with the cell surface membrane. A student recorded how many times the contractile vacuole filled and then emptied when the cell was placed in solutions with different water potentials. The findings are shown in the table. Which statement accounts for the pattern seen as the water potential of the external solution decreased?
- AThe water potential gradient between the cell and the solution increased, causing water to move into the cell more rapidly and the contractile vacuole to empty more frequently.
- BThe water potential gradient between the cell and the solution increased, causing water to move into the cell less rapidly and the contractile vacuole to empty less frequently.
- CThe water potential gradient between the cell and the solution decreased, causing water to move into the cell more rapidly and the contractile vacuole to empty more frequently.
- DThe water potential gradient between the cell and the solution decreased, causing water to move into the cell less rapidly and the contractile vacuole to empty less frequently.