Which major atmospheric component is chiefly a product of life processes?

Question

Quizplus · Accepted Answer

Oxygen is the major atmospheric component generated by life processes such as photosynthesis, where plants and some other organisms use sunlight, carbon dioxide, and water to produce oxygen as a waste product. Carbon dioxide is also produced in this process, but it is not a major atmospheric component, and its concentration is relatively low compared to oxygen and nitrogen. Water is not a product of life processes in the atmosphere but is recycled through the hydrologic cycle. Hydrogen sulfide is a minor atmospheric component and is mostly produced by volcanic activity and some bacterial processes, and nitrogen is a major atmospheric component, but it is not a product of life processes.

Which Major Atmospheric Component Is Chiefly a Product of Life