<Li> One product of oxygenase activity is phosphoglycolate (2 carbon) instead of 3 - phosphoglycerate (3 carbon). Phosphoglycolate cannot be metabolized by the Calvin - Benson cycle and represents carbon lost from the cycle . A high oxygenase activity, therefore, drains the sugars that are required to recycle ribulose 5 - bisphosphate and for the continuation of the Calvin - Benson cycle . </Li> <Li> Phosphoglycolate is quickly metabolized to glycolate that is toxic to a plant at a high concentration; it inhibits photosynthesis . </Li> <Li> Salvaging glycolate is an energetically expensive process that uses the glycolate pathway, and only 75% of the carbon is returned to the Calvin - Benson cycle as 3 - phosphoglycerate . The reactions also produce ammonia (NH), which is able to diffuse out of the plant, leading to a loss of nitrogen . </Li> <Dl> <Dd> <Dl> <Dd> A highly simplified summary is: </Dd> </Dl> </Dd> </Dl>

Which of the following are the three stages of photosynthesis in plants