SOLUTION

The process by which green plants make their own food (like glucose) from carbon dioxide and water by using sunlight energy (in the presence of chlorophyll) is called photosynthesis. 

Photosynthesis by Plant Parts Other Than Leaves

Normally photosynthesis takes place only in the leaves of plants In some plants, however, photosynthesis also takes place in other parts of plants such as “green stems” and “green branches”. The green stems and green branches can do photosynthesis because they contain chlorophyll. For example, desert plants such as cactus have tiny, spine-like leaves to reduce the loss of water by transpiration. These tiny, spine-like leaves of a cactus plant cannot do photosynthesis. The stem and branches of a cactus plant are green which contain chlorophyll. So, the green stem and green branches of a cactus plant carry out the process o photosynthesis to make food for the plant. Please note that only those stems and branches which are green in colour can do photosynthesis Now, the stems and branches of all the plants and trees are not green So, the stems and branches of all the plants and trees cannot do photosynthesis.