The Importance of Contractile Vacuoles in Regulating Water Potential

What is the relationship between contractile vacuoles and water potential?

a) The contractile vacuole decreases water potential.

b) The contractile vacuole increases water potential.

c) The contractile vacuole is unrelated to water potential.

d) The contractile vacuole maintains constant water potential.

Answer:

Contractile vacuoles help maintain water balance within cells by expelling excess water, which decreases the water potential inside the cell.

Explanation:

The relationship between contractile vacuoles and water potential is crucial for organisms, especially those living in hypotonic environments. Contractile vacuoles play a vital role in maintaining water balance by expelling excess water, thus preventing cell lysis caused by excessive internal water pressure.

In a hypotonic environment where the water potential inside the cell is higher than outside, water tends to enter the cell through osmosis. Contractile vacuoles must actively pump out this excess water to preserve cell integrity. By expelling the excess water, the water potential inside the cell decreases, preventing the cell from taking in too much water and bursting.

It is important to note that osmotic potential corresponds to solute potential. If a cell malfunctions and cannot expel water properly, it can lead to cell swelling and potential lysis due to the imbalance of water potential across the cell membrane.

In summary, contractile vacuoles are essential for regulating water potential. When functioning correctly, they decrease the water potential inside the cell by removing excess water. However, if a malfunction occurs and they cannot expel water effectively, the water potential inside the cell increases, posing a risk of cell damage.