How do leaves maximize the intake of carbon dioxide?

The correct choice highlights two key adaptations of leaves that enable them to effectively maximize carbon dioxide intake. Firstly, leaves possess stomata, which are small openings on the surface of the leaf. These stomata allow carbon dioxide from the atmosphere to diffuse into the leaf for photosynthesis. The regulation of these stomata, which can open and close in response to environmental conditions, ensures that the leaf can optimize gas exchange while minimizing water loss.

Secondly, the flattened shape of the leaf increases the surface area exposed to sunlight and air, facilitating a greater opportunity for gas exchange. This flat structure ensures that most of the photosynthetic cells within the leaf are close to the surface, enabling efficient absorption of carbon dioxide, as well as sunlight for photosynthesis.

In contrast to this option, having thick outer layers would inhibit gas exchange by making it harder for carbon dioxide to enter the leaf. Being dormant during the day would limit the active intake of carbon dioxide when sunlight is available for photosynthesis. Reducing surface area would also decrease the efficient capture of carbon dioxide because there would be less area for gas exchange to occur. Hence, the combination of stomata and a flattened shape is vital for maximizing carbon dioxide intake effectively.