Question

We continuously breathe oxygen and also the population is rising at an alarming rate. So why is the oxygen not fully used up?

• A. Once oxygen is consumed, we can breathe other gases.
• B. Oxygen mixed with other gases is used as an alternative when there is a shortage of pure oxygen.
• C. The plants take carbon dioxide and releases oxygen while animals take oxygen and releases carbon dioxide, so the balance is maintained.
• D. The Earth's atmosphere has a large reservoir of oxygen.

Answer 1

The correct option is C

The plants take carbon dioxide and releases oxygen while animals take oxygen and releases carbon dioxide, so the balance is maintained.

Plants make their own food in a process called photosynthesis. In this process, carbon dioxide is used and oxygen is produced along with food.

Animals, on the other hand, take in oxygen during respiration and expel out carbon dioxide. Thus, the balance of oxygen and carbon dioxide in the atmosphere is maintained. This also shows the interdependence of plants and animals.