Why does photosynthesis only occur in the leaves of a plant?
Because that’s where the photosynthesis reaction centers (chloroplasts) are located. And they are located in the leaves, because photosynthesis requires sunlight, and the leaves are particularly well designed to capture as much sunlight as possible as well as allowing the exchange of CO2 and O2, and delivery of water from the roots since water is another requirement for photosynthesis.
