Question

Write any two ways by which plants obtain carbon dioxide. What causes the opening and closing of the stomata?

Hint:

Guard cells regulate stomatal movement based on water availability.

Answer 1

Two ways by which plants obtain CO$_2$: 1. From the atmosphere through tiny pores called stomata present in the leaves. 2. Through respiration of plant cells, which produces carbon dioxide internally that can be reused in photosynthesis. Opening and Closing of Stomata: The opening and closing of stomata is controlled by the turgidity of guard cells. When guard cells are full of water (turgid), stomata open. When they lose water (flaccid), stomata close.