Tag: angiosperms

 A ligule is an outgrowth present at the junction of leaf sheath and lamina in grasses. It occurs at the end of petiole at the leaf base. It is a strap-shaped extension of the corolla. It is a membranous appendages.

The seed coat encloses an embryo wich is differentiated into radicle (give rise to primary root), plumule(give rise to aerial shoot) and cotyledons (seed leaves). The number of cotyledons may be one or two. These are different from foliage leaves. Some times they store reserve food materials or serve as photosynthetic organs in young seedling. The plumule is surrounded by a conical protective sheath, called coleoptile.

A. Leaves have reticulate venation – dicotyledons

B. Stems have annual rings – dictyledons

C. Seed have two storage organs -dicotyledons

D. Stems have scattered conducting strands – monocotyledons

So, the correct option is ‘stems have scattered conducting strands’.    

Smilax is an economically important monocotyledonous flowering plant belonging to family Liliaceae. It is found in tropics and subtropics worldwide. They are climbing flowering plants, many of which are woody and thorny. Usually, monocots show parallel venation (veins present in the leaf are arranged parallel to each other), but Smilax shows reticulate venation (veins are interconnected and forms web-like structure). So, the correct answer is 'Smilax'.

The cotyledons are attached to the curved embryonal axis (Tigellum) at the cotyledonary node. The ,micropylar end of embryonal axis is rod- shaped and slightly bulged. It is called radicle (or embryonic root). The other side of embryonal axis lies in between the two cotyledons. It is called plumule( or the shoot tip).

Most of the oil yielding plants belong to the family Cruciferae.