Question

Do red leaves and yellow leaves also reflect green light? If yes, then why is their colour different? Also, how does photosynthesis occur in plants with such leaves? Since there is no green pigment i.e. chlorophyll, then how does photosynthesis occur without chlorophyll?

Answer 1

(a) Chlorophyll absorbs red and blue light and the green light is reflected back due to which the leaves appear green in colour. Now apart from chlorophyll, there are other pigments also present in the leaves such as carotenoids, xanthophylls and anthocyanin. The concentration of these pigments is usually less than chlorophyll; however, in some plants their concentration is high. So, these pigments absorb different color of light, thereby, their leaves appear to be of different colours to human eyes.

(b) Plant leaves obtain different colours due to the presence of different types of pigment like carotinoids (yellow, orange), anthocyanin (purple) etc. But chlorophyll is also present on these leaves but remains hidden or musked among other pigments. These chlorophylls perform photosynthesis just like other green plants. So coloured plant leaves also carry out photosynthesis like green plants.