Transport in Plants Question 21
21. Water potential is equal to
(a) $\psi_s+$ O.P.
(b) $\psi_s=$ T.P.
(c) $\psi_p+\psi_w$
(d) $\psi_s+\psi_p$
Show Answer
Answer : d
Hints & Solutions
(d) Water potential is defined as the difference between the chemical potential of water at any point in a system and that of pure water under standard conditions. The unit of measurement of water potential is pascal, $Pa$ (1 mega pascal, $Mpa=10$ bars). It is represented by greek letter PSi $(\Psi)$. Water potential has two componentssolute potential which is always negative and pressure potential which is usually positive. Therefore water potential $\Psi_w$ is expressed as: $\Psi_W=\Psi_s+\Psi_p$