AP BIOLOGY

Detailed explanation-1: -The xylem channels of leaves have lowest water potential because they have very high solute concentration due to loss of water during transpiration.

Detailed explanation-2: -If you have a really high concentration sugary solution, that is said to have a low water potential (think that all the water is interacting with the sugar). If you have a low concentration sugary solution, this has a high water potential.

Detailed explanation-3: -The water potential of pure water at normal temperature and pressure is zero. If we add sugar to water, the water potential decreases. The reason for that is the presence of solute particles that reduces the free energy of water and thus decrease the water potential.

Detailed explanation-4: -Water potential depends upon the solute concentration in a solution because increased solute concentration may result in decreased osmotic value and low water potential. Potassium nitrate is a crystalline salt and polar molecule, but sucrose is nonpolar and has higher osmolarity, resulting in lower water potential.