Define Mesophyll tissue. What are the tissues present in it?

A vertical section of a dorsiventral leaf through the lamina shows three main parts: epidermis, mesophyll, and vascular system. In leaves, the ground tissue is made of thin-walled, chloroplast-containing cells called the mesophyll tissue, located between the upper and lower epidermis.

• In dicot leaves, mesophyll is differentiated into palisade and spongy tissues.
• In monocot leaves, mesophyll is composed mainly of iso-diametric cells.
• Mesophyll cells have large intercellular spaces that allow free movement of carbon dioxide and play a major role in photosynthesis.
• The mesophyll is made up of parenchyma cells and is of two types:

1. Palisade Parenchyma

• Consists of 1–3 layers of elongated, columnar, closely packed cells.
• Contains abundant chloroplasts, making it the primary photosynthetic tissue of the leaf.
• Palisade cells hold nearly 70% of the chloroplasts in the leaf.

2. Spongy Parenchyma

• Made up of oval, rounded, or irregular cells with large intercellular spaces.
• Provides a large surface area for gas exchange during photosynthesis.
• Contains fewer chloroplasts compared to palisade cells.