$A$. Much of the nitrogen in xylem sap is carried in organic form.
$B$. In phloem,the movement of nutrients is always unidirectional.

Give differences between:
$(1)$ Diffusion and Osmosis
$(2)$ Transpiration and Evaporation

If $T = \text{True}$ and $F = \text{False}$, then select the correct option for the following statements:
$1.$ Diffusion is a passive process.
$2.$ $\Psi_S$ (solute potential) is always negative.
$3.$ Osmosis does not depend on a pressure gradient.
$4.$ Mycorrhiza is a symbiotic association of fungus and algae.

Which of the following statements are true or false?
$I.$ The positive hydrostatic pressure is called turgor pressure.
$II.$ Wall pressure is exerted to prevent the increase of protoplasm size.
$III.$ Diffusion is more rapid in liquids than in gases.
$IV.$ Diffusion of water through a semi-permeable membrane is called imbibition.
$V.$ Osmosis is the movement of a substance,which takes place along a diffusion gradient.

The ringing experiment is related to:

- Transport of water and minerals in $Xylem$ is $\underline{A}$.
- Transport of organic and mineral nutrients is $\underline{B}$.