question_answer 56)

  Is it correct to say that photosynthesis occurs only in leaves of a plant? Besides leaves, what are the other parts that may be capable of carrying out photosynthesis? Justify.

Answer:

                  Photosynthesis is a process which mainly occurs in leaves of all green plants. The plants have designed their leaf in such a way that it is able to trap solar radiation and effectively convert solar/light energy to chemical energy. But biology is science of exceptions. Some plants carry out photosynthesis in modified plant parts other then leaves. Few examples are as follows 1.         When roots develop chlorophyll and start photosynthesis, they are called assimilitory roots. Trapa and Tinospora are the examples of assimilatory roots. 2.       Stem as Photosynthetic Organ In Opuntia, the stem gets modified to take up the function of leaves. It becomes flattened, thick and succulent and perform photosynthesis. Such structures are called phylloclade. 3.       Petiole as Photosynthetic Organ In Australian Acasia the petiole takes the shape and function of photosynthesis because leaf lamina soon fails off.