Question

A non-biological source of carbon dioxide is

• A. Volcanic eruptions
• B. Hot springs
• C. Weathering
• D. All of the above

Answer 1

The correct option is A Volcanic eruptions

The only source of carbon is the atmospheric carbon dioxide. The gas is used by all the plants for photosynthesis which releases oxygen as end product. The carbon and oxygen supplied by CO₂ are retained in the living matter till death.

The oxygen is used as a fuel for respiration by both plants and animals. This releases CO₂ as end by-product. CO₂ is also released by combustion i.e. burning of forests and fossil fuels.

Occasionally, CO₂ is added to the atmosphere by volcanic eruptions. When volcanoes burst, magma is released which contains many dissolved gases including CO_2.

So, a volcano is a non biological source of carbon dioxide.

So, the correct answer is 'Volcanic eruptions'.