EVERYDAY SCIENCE

Detailed explanation-1: -Carbon dioxide and oxygen cannot pass through the cuticle, but move in and out of leaves through openings called stomata (stoma = “hole"). Guard cells control the opening and closing of stomata. When stomata are open to allow gases to cross the leaf surface, the plant loses water vapor to the atmosphere.

Detailed explanation-2: -Through photosynthesis, they use sunlight and carbon dioxide to make food, belching out the oxygen that we breathe as a byproduct. This evolutionary innovation is so central to plant identity that nearly all land plants use the same pores-called stomata-to take in carbon dioxide and release oxygen.

Detailed explanation-3: -During respiration, which occurs in most plants at night, plants take in oxygen through the closed stoma and release carbon dioxide into the environment. Both carbon dioxide and oxygen enter and exit through the stoma by simple diffusion down their concentration gradients.

Detailed explanation-4: -During photosynthesis, carbon dioxide is taken in from the atmosphere through the stomata and oxygen is released as a waste product.