Question

Amazon rainforests are considered as ‘lungs of the planet’ as they contribute ______ of the total oxygen in the earth’s atmosphere.
(A) 10%
(B) 15%
(C) 20%
(D) 30%

Answer 1

Hint: The Amazon rainforests are also known as lungs of the planet as it is contributing oxygen to be consumed by the other animals. It covers an area of about 55, 00, 000 square kilometre.

Complete answer:
The term rainforests refer to those forests where there is continuous rainfall. There are two types of rainforests, namely tropical and temperate rainforests. Amazon rainforests come under the type, Tropical rainforests. Among all the rainforests found on Earth, the largest rainforests are Amazon.
It comprises billions of living organisms, including microbes, insects, plants and animals. It comprises nearly 10% of the total world’s known biodiversity. Approximately, 137 living species are going extinct due to deforestation. There are more than 300 billion individual trees belonging to 16,000 different tree species and nearly 40,000 varying plant species.

Presence of billions of tree and plant species takes in tonnes of carbon dioxide (photosynthesis) and converts it to oxygen. Carbon dioxide is the major pollutant and heat-trapping gas which leads to global warming. As amazon rainforests take in carbon dioxide and give out 18% to 20% of oxygen, they are considered as the lungs of the planet.

Hence the correct answer is option(C)

Note: Remembering the exact percentage of oxygen released by the amazon rainforests is essential to answer this question. Amazon plays a major role in the environment protection and also gives the majority of oxygen to the earth.