Differentiate between diffusion and translocation in plants.

In a girdled plant,when water is supplied to the leaves above the girdle,leaves may remain green for some time,then wilt and ultimately die. What does it indicate?

Given below are two statements in relation to the limitations of the capillarity theory of water transport in plants.
Statement $I$: Xylem, i.e., the capillarity tube, must be with closed end walls and not hollow.
Statement $II$: The capillarity tube, i.e., xylem, is not in direct contact with soil water and contains a barrier of root cells between the xylem and soil water.
In the light of the above statements, choose the most appropriate answer from the options given below:

$A-$ Diffusion is a very slow process and is responsible for the short-distance movement of molecules.
$R-$ Water,minerals,and food are generally moved by a mass or bulk flow system.

Choose the correct option:
$(1)$ The transport in xylem is always $unidirectional$.
$(2)$ The process of loss of water in the form of vapour by plants is called $transpiration$.

Assertion: When the ambient temperature is high and soil contains excess of water,the plants tend to lose water in the form of droplets from lenticels.
Reason: Root pressure regulates the rate of loss of water from lenticels.