Boris is a farmer. His farm is near the sea. Often sea water floods his fields, causing his crops to wilt and die. Does sea water have a higher or lower water potential than the root cells of the crops?

Sea water has a lower water potential than the root cells of the crops. Here's why:

1. Water potential is a measure of the potential energy in water and is represented by the Greek letter Psi (Ψ). It determines the direction in which water will flow (from areas of high water potential to areas of low water potential).

2. Pure water has the highest water potential, set at zero (0). When substances are dissolved in water, like salt in sea water, it lowers the water potential.

3. Sea water is salty and therefore has a lower water potential than pure water or the water inside a plant's root cells.

4. When Boris's fields are flooded with sea water, the water in the root cells of the crops moves out of the cells and into the salty sea water, trying to reach an equilibrium. This is due to osmosis - the process where water moves from areas of high water potential (the root cells) to areas of low water potential (the sea water).

5. This movement of water out of the root cells causes the crops to wilt and die, as they lose water and become dehydrated.