Question

When osmotic potential is either zero or negative and pressure potential is positive, then the water potential will be

• A. Negative
• B. Positive
• C. Sometimes negative sometimes positive
• D. None of the above

Answer 1

The correct option is A Negative

Water potential of a solution is always negative because by convention water potential of pure water is assumed to be zero. When solutes are dissolved in water, then water potential decreases. But for a cell the formula to calculate water potential is that water potential is algebraic sum of osmotic potential (which may be zero or negative) and pressure potential which is always positive. Hence, depending on the relative magnitudes of osmotic potential and pressure potential; the value of water potential can be negative or positive.