Why is upper surface of dicot leaf much darker than the lower surface anything?

The upper surface of a dicot leaf is typically darker than the lower surface due to the higher concentration of chlorophyll in the palisade mesophyll, which is more abundant on the upper side. This structure is optimized for light absorption, maximizing photosynthesis. In contrast, the lower surface has more air spaces and stomata for gas exchange, leading to a lighter coloration. Additionally, the presence of protective features like a waxy cuticle may also contribute to the appearance of the lower surface.