The gaseous product of a process in plants is a reirement for another vital process that releases energy. Given below are four combinations of the process and product. Identify the correct answer.

The process of photosynthesis in plants uses carbon dioxide and water in the presence of sunlight to produce glucose and oxygen [4]. Oxygen is released as a gaseous byproduct of this process [3]. This oxygen is then a vital requirement for another essential process called aerobic respiration. During respiration, plants (and other organisms) break down glucose in the presence of oxygen to release energy, which is used for growth and development [4]. The chemical equations for these two processes are essentially opposites: photosynthesis stores energy by producing glucose and oxygen, while respiration releases that energy by consuming oxygen and glucose to produce carbon dioxide and water. Therefore, the gaseous product of photosynthesis (oxygen) is the requirement for respiration, the vital process that releases energy.

Sources

1. [4] Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 1: BASIC CONCEPTS OF ENVIRONMENT AND ECOLOGY > photosynthEsis. > p. 14
2. [1] Science-Class VII . NCERT(Revised ed 2025) > Chapter 10: Life Processes in Plants > 10.2.4 How do leaves exchange gases during photosynthesis? > p. 146
3. [3] Science-Class VII . NCERT(Revised ed 2025) > Chapter 10: Life Processes in Plants > In a Nutshell > p. 150