The unit of water potential is $...............$.

Provide definitions/explanations for the following terms:
$(1)$ Water potential
$(2)$ Translocation of substances

What would be the solute potential $(\Psi_s)$ of the cell sap in cell-$A$ and cell-$B$ respectively?

Why is solute potential always negative? Explain $\Psi_{w} = \Psi_{s} + \Psi_{p}$.

The water potential of pure water at standard atmospheric pressure is $.............$.

Study the following table showing the components of water potential in closely arranged mesophyll cells namely $A, B$ and $C$.

Cell	Osmotic Potential (MPa)	Pressure Potential (MPa)
$A$	$-0.21$	$0.05$
$B$	$-0.22$	$0.02$
$C$	$-0.23$	$0.05$

Identify two of the following,which show correct direction of water movement between two cells.
$I. A \rightarrow B$ $II. B \rightarrow C$ $III. C \rightarrow A$ $IV. C \rightarrow B$