Question

Which of the following process returns the oxygen back to the atmosphere?

• A. Respiration
• B. Photosynthesis
• C. Oxide formation
• D. Combustion

Answer 1

The correct option is B Photosynthesis

$\bullet$ Photosynthesis: It is the process in which carbon dioxide and water, in the presence of sunlight, is converted into glucose and oxygen.
$\bullet$ Respiration: It is the process by which food is broken down to obtain energy with the help of oxygen.
$\bullet$ Combustion: It is a chemical process which makes use of oxygen in the air to produce heat and light.
$\bullet$ Oxygen is further used up when nitrogen reacts with it to form oxides of nitrogen.