Q. In a fully turgid cell :
(a) Ψs is negative and Ψp is positive
(b) Ψp is negative and Ψs is positive
(c) Both Ψp and Ψs are positive
(d) Both Ψs and Ψp are negative
Solution :
Correct option : A
In a fully turgid cell the protoplast exerts a pressure on cell wall. This pressure is called turgor pressure or pressure potential (Ψp) and is always positive. The cell has some solute concentration, which reduces the water potential from zero (the water potential of pure water). Hence the solute potential (Ψs) is negative.