Question

Balance of oxygen and carbon dioxide in atmosphere is maintained by:
A. Plants
B. Animals
C. Humans
D. All of the above

Answer 1

Hint: Plants take up carbon dioxide in the process of synthesis, and give out oxygen. Humans,animals and plants require oxygen for respiration and give out carbon dioxide. The total balance can be maintained by constant regulation in these values.

Complete answer:
Atmosphere is made up of different entities which are living in it.
Most of the atmosphere is covered with plants.
We know that plants take part in photosynthesis.
Photosynthesis is the process of conversion of carbon dioxide and water to glucose in the presence of sunlight and release of oxygen.
This process is specific to plants only and the green pigment in plants, chlorophyll is responsible for photosynthesis. No other part of the plant can take part in photosynthesis.
Respiration is a process of taking in oxygen gas, and giving out carbon dioxide. This process is done by Plants, animals and Human beings. Oxygen which is taken in through the nose, is supplied to the lungs which is in turn supplied to the blood vessels, which causes the blood to get oxygenated.
Hence, Plants, Animals and Human beings are responsible for the balance of oxygen and carbon dioxide in the atmosphere since the daily life biological processes involved are responsible for production or consumption of oxygen and carbon dioxide.

So, the correct answer is option D.

Note: The conversion of carbon dioxide to give glucose during photosynthesis is the exact opposite of cellular respiration. All the living things on earth are responsible for the balance of oxygen and carbon dioxide.