What is the waste gas produced during photosynthesis?
It is unfortunate that the term “waste” has been applied to the oxygen released during photosynthesis. Although there is more oxygen released than can be used by the plant, the plant itself will use oxygen gas in cellular respiration in the tissues that cannot photosynthesize, such as inside the stem and the roots. As pointed out by another respondent, water vapor is also released during photosynthesis. It helps to cool the leaves and also helps to transport dilute solutions of minerals throught the xylem tissues of the plant.
