Select correct features w.r.t. trichomes in the shoot system:
$(a)$ Usually unicellular
$(b)$ Branched or unbranched
$(c)$ May be secretory
$(d)$ Soft or stiff
$(e)$ Helps against transpiration

$I.$ Phloem transports the food materials usually from the leaves to other parts of the plant.
$II.$ Phloem in the angiosperm is composed of sieve tube elements,companion cells,phloem parenchyma,and phloem fibres.
Identify which of the following statements is correct and select the correct option.

The most primitive type of stele is

The primary function of a vessel in plants is:

Amphivasal or leptocentric vascular bundles are found in

What is present on the surface of the leaves which helps the plant prevent loss of water but is absent in roots?