2.67a Excretion in plants

1. photosynthesis-involves the leaf absorbing sunlight and while doing so it combines carbon dioxide and water to produce glucose and oxygen, a gas which is given off. 
2. In this case, the gas which is given off, oxygen, is an example of excretion as its a waste molecule.
3. Excretion- the release of metabolic waste. 
4. Respiration-glucose and oxygen are used, and through a series of enzyme reactions, the glucose molecules break down and the energy is used to form ATP, water, and carbon dioxide. In this process, the waste product is carbon dioxide and water. However, like the oxygen in the reaction above, Carbon dioxide is also given off, its a metabolic waste therefore its excretion. 
5. Plants excrete oxygen when they photosynthesize and they excrete Carbon dioxide when they go through the process of respiration.