Question

2. Structures present on the undersurface of
leaves for exchange of gases​

Answer 1

Stomata are generally more numerous on the underside of leaves. They provide for the exchange of gases between the outside air and the branched system of interconnecting air canals within the leaf. A stomate opens and closes in response to the internal pressure of two sausage-shaped guard cells that surround it.

Answer 2

Answer:

The only way for gases to diffuse in and out of the leaf is though small openings on the underside of the leaf, the stomata. ... These stomata can open and close according to the plant's needs. The tissues of the leaf in between the epidermal cells, into which gases diffuse from the stomata, are called mesophyll.