B.

pores on lateral walls

The wall of both vessel and sieve tube elements are perforated by large opening. Due to this adaptation, the cell to cell contact is possible. The vessels are nucleated whereas the sieve tube elements are enucleated.

C.

Vasculature without cambium

The characteristic feature of monocot root is presence of vasculature without cambium. The vascular bundles are alternate and radial and arranged in the form of a ring around a central pith. Phloem and xylem bundles are separated by narrow strips called conjunctive tissue and it does not take part in cambium formation. So, the vascular bundles in monocots are closed and do not show any secondary growth.

C.

Petals in the flowers of cotton (Gossypium sp) china rose (Hibiscus rosa sinesis), etc, show twisted aestivation. In this type of aestivation, a regular overlapping of petals occurs where one margin of each petal overlaps with the next one petal.

B.

many xylem bundles

The vasculature is radial in dicot root i.e.,xylem bundles alternate with phloem bundles. Usually vascular bundles are 2-6 in number while in monocot root the vascular strand consists of several (8 or more) alternate radial xylem and phloem bundles. Secondary growth takes place in dicot root while absent in monocot roots and annual rings do not form. 

C.

Puccinia graminis

Black (stem) rust of Wheat is caused by Puccinia graminis tritici, a fungus belonging to Sub-class-Teliomycetidae, Order-Uredinales. It is a heteroecious species which completes its life cycle on two plants, ie, barberry (Berberis) plant and wheat (Triticum aestivum).