Oxygen plays a critical role in respiration, the energy-producing chemistry that drives the metabolisms of most living things. We humans, along with many other creatures, need oxygen in the air we breathe to stay alive. Oxygen is generated during photosynthesis by plants and many types of microbes.
All living organisms except plants need oxygen, as oxygen is what ignites all living things .. Plants take carbon dioxide and produce oxygen gas through the process of photosynthesis.
