Question

Describe the internal structure of the dicot leaf with the help of diagrams.

Answer 1

Hint:- Dicot leaves have a network like venation present in them. They do not have parallel venation, unlike monocot leaves. Dicot leaves have two types of mesophyll cells present in them, namely palisade mesophyll and spongy mesophyll cells.

Complete Answer:-In dicot leaves, the presence of epidermis can be seen on both the sides of the leaves that is, the upper surface as well as the lower surface of the leaves. The epidermal layer is composed of barrel-shaped cells which are compactly arranged together. The presence of a thick cuticle layer on the upper surface of the leaf can be seen which covers the epidermal layer. The stomata are present on the lower surface of the leaf and are very less in number on the upper surface of the leaf. The mesophyll cells of the leaves are differentiated into palisade cells and spongy mesophyll cells. Palisade cells have elongated cells that are arranged in two layers and are present beneath the upper epidermis. These cells contain chloroplast in them and they have intercellular spaces present between them. Spongy parenchyma cells are present below and above the vascular bundles and are known as the extension of bundle sheath cells. Spongy cells also have chloroplast on them and they leave big intercellular spaces in between them. The vascular bundles present are conjoint, collateral, and closed. Xylem cells are present near the upper epidermis and phloem cells are present near the lower epidermis of the leaf.

Note:- To distinguish the monocot leaf from the dicot leaf, one should observe the mesophyll cells. In dicot leaves, the spongy mesophyll cells can be seen clearly and the intercellular spaces can also be seen. The stomata in dicot leaves are abundant on the lower surface of the leaf.