In a C3 plant such as wheat explain what happens to the oxyg

In a C3 plant such as wheat, explain what happens to the oxygen released when the day is mild and cool compared with when the day is hot and dry.

Solution

The hot and dry days refer to days with high sunlight intensity and warmer temperatures. The increased sunlight intensity increases the rate of photosynthesis in C₃ plants under hot conditions. Since RUBISCO fixes both CO₂ and oxygen, the increased rate of photosynthesis also increases the oxygen concentration and thereby increasing the rate of photorespiration. So, most of the oxygen relased during photosynthesis enters the photorespiratory pathway under hot and dry conditions in these plants. On the other hand, mild and cool days lower down the rate of photosynthesis which in turn also lowers down the rate of photorespiratory activity of RUBISCO owing to reduced oxygen concentration. Under these conditions, much of the oxygen is released into atmosphere.