Identify $P, Q,$ and $R$ in the given internal structure.

In the stem of barley $(Hordeum \text{ } vulgare)$, the vascular bundles are .......

The transverse section of a plant material shows the following anatomical features under microscope $:-$
$(a)$ Collenchymatous hypodermis
$(b)$ Sclerenchymatous pericycle located just above phloem bundles in semi-lunar patches.
$(c)$ Vascular bundles are arranged in a ring.
$(d)$ Vascular bundles are conjoint & open.
Plant material should be :

The transverse section of a plant material shows the following anatomical features: $(a)$ the vascular bundles are conjoint,scattered,and surrounded by sclerenchymatous bundle sheaths,$(b)$ phloem parenchyma is absent. What will you identify it as?

Polycyclic condition is commonly found in?

Reduction in vascular tissue,mechanical tissue,and cuticle is a characteristic of ..........