(i) The term lungs of the planet is used for
(ii) What is the main reason of deforestation of Amazon rain forest.
(iii) How can high degree of endemisms is responsible for extinction of species.

Taj Mahal is regarded as eighth wonder the world. Millions of people from India and from abroad visit this great historic monument every year. They appreciate the architecture and the carvings. It is indeed, very prestigeous for every Indian. But over the years, it has faced immense pollution problems. It has lost its Iustre due to the presence of traces of hydrogen sulphide and other pollutants present in air. (i)What is the main reason for the damage done to Taj Mahal and other historical monuments ? (ii) How is damage actually caused ? (iii) Suggest some ways to check the pollution ?

Since the origin of life on Earth, there were five episodes of mass extinction of species . (i) How is the 'Sixth Extinction', presently in progress, different from the previous episodes ? (ii) Who is mainly responsible for the 'Sixth Extinction' ? (iii) List any four points that can help to overcome this disaster.

During monsoon days, a blue green layer was developed on moist soil of village streets making them slippery. On the instruction of science teacher Ghanshyam collected this upper slippery layer of soil from the village street and dried it. Then he added this powder to this crop field. He got very good crop yield without using any fertilizers (i) Which group of organisms is responsible for this blue green layer ? (ii) What is the possible reason for increased crop yield after addition of blue green layer to the fields (iii) Name one blue green alga which do nitrogen fixation (iv) Name one blue green alga which is a good source of protein.