Question

Answer the following question.

Define and or explain the term:

Water potential

Answer 1

i. Chemical potential of water is called water potential.

ii. It is represented by Greek letter psi (ψ).

iii. The unit of measurement of water potential is bars/ pascals/ atmospheres.

iv. Water potential of protoplasm is equal but opposite in sign to DPD. It has a negative value.

v. Water potential of pure water is always zero. The addition of any solute in it decreases its psi (ψ) value. Therefore, it has a negative value.

vi. Difference between water potential of the adjacent cells decides the movement of water through plasmodesmata across the cells.

vii. Water always flows from less negative potential to more negative water potential (i.e. from high water potential area to low water potential area).