CBSE BoardEnglish MediumSTD 7Social StudiesAir3 Marks
Question
Explain how the oxygen and carbon dioxide balance is maintained in air?
✓
Answer
Green plants use carbon dioxide to make their food and during this process release oxygen:
Humans and animals release carbon dioxide and take oxygen from air.
The amount of carbon dioxide released by them is equal to amount used by plants to make their food. Hence a balance is maintained.
But now the excess of carbon dioxide is released by burning of fuels. The reduction in number of plants upset the balance of gases like carbon dioxide affecting earth’s weather and climate.
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