In what respect do the conducting elements of the $Xylem$ differ from each other?

Specialised epidermal cells surrounding the guard cells are called

Select the correct statements.
$I.$ Epidermal cells have a small amount of cytoplasm and a large vacuole.
$II.$ $A$ waxy layer,the cuticle,is absent in roots.
$III.$ Root hairs are unicellular,while stem hairs/trichomes are multicellular.
$IV.$ Trichomes are branched/unbranched,soft/stiff,and secretory or transpiration-preventive.
$V.$ Guard cells are dumb-bell-shaped in monocots (e.g.,grass) and bean-shaped in dicots.

$A$ bicollateral vascular bundle has the following arrangement of tissues:

$A$ student observed grass and $Hibiscus$ plants in his garden during noon. To his surprise,only the leaves of grass were found rolled inwards. The reason could be

Leaf mesophyll cells are included in $:-$