Which plant structure is primarily responsible for photosynthesis?

Leaves are primarily responsible for photosynthesis in plants. They contain chlorophyll, the green pigment that captures sunlight, which is essential for the process of converting carbon dioxide and water into glucose and oxygen. The structure of leaves is specifically adapted for this function; they have a large surface area to maximize light absorption and contain small openings called stomata that facilitate the exchange of gases.

Roots are primarily involved in water and nutrient absorption from the soil and do not play a role in photosynthesis. Stems support the plant and transport nutrients between roots and leaves but are not involved in the actual photosynthetic process. Flowers are mainly reproductive structures and are not directly involved in photosynthesis either. Thus, leaves are the key structures in enabling plants to perform photosynthesis effectively.