Question

Why a large number of stomata are present at the lower surface of the dicotyledonous leaves in the terrestrial plants?

Answer 1

Stomata are small pores present on the surface of leaves which aids in exchange of gases. They open during the day in presence of sunlight. If the numbers of stomata are present at the upper surface of the dicotyledonous leaves, it will lead to more water loss during daytime and high temperature. This may lead to wilting of leaves. Hence, to prevent excessive water loss in terrestrial plants, the large number of stomata are present at the lower surface of leaves.