Question

Dorsiventral leaf has
A. Spongy parenchyma on upper side
B. Spongy parenchyma on both sides
C. Palisade parenchyma on lower side
D. Palisade parenchyma on upper side

Answer 1

Hint: Mesophyll cells in the dorsiventral leaf contain two types of cells – palisade parenchyma and spongy parenchyma and this type of leaf is present in the dicot plants.

Complete answer:
The dorsiventral leaf is the characteristic of the dicotyledonous plants and the leaf mainly consists of three parts- epidermis, the outermost layer, mesophyll tissue and the vascular system.
In dorsiventral leaf, a tissue which is present between the upper and lower epidermis is known as Mesophyll. The chloroplast is present in this tissue and it performs the process of photosynthesis. This mesophyll tissue is made up of two types of parenchymatous cells called spongy and palisade parenchyma.
The palisade parenchyma is present on the upper side whereas the spongy parenchyma is placed on the lower side of the epidermis. The cells in the palisade parenchyma are elongated and are placed parallel to each other and arranged vertically whereas the cells in the spongy parenchyma are loosely arranged and are oval or round in shape. These cells have large spaces and air cavities present between them.
These leaves have reticulate venation in them and the vascular bundles present in the leaves are surrounded by layers which are made up of thick walled cells and are known as bundle sheath cells.

So, the correct answer is (D).

Note: The leaves in monocot are isobilateral and in this, mesophyll tissue does not differentiate into palisade and spongy parenchyma. Venation is of parallel type and they have colorless, empty cells called as bulliform cells which are the modifications of adaxial epidermal cells and the veins.