What are the two ways in which carbon dioxide is fixed to keep its percentage almost constant?
Carbon dioxide percentage is kept almost costant by the following ways:
(i) By photosynthesis - green plants convert carbon dioxide into glucose in the presence of sunlight.
(ii) Many marine animals (like unio and pila) use carbonates dissolved in sea-water to make their shells.
Why is the atmosphere essential for life?
Why is water essential for life?
How are living organisms dependent on the soil? Are organisms that live in water totally independent of soil as a resource?
You have seen weather reports on television and in newspapers. How do you think we are able to predict the weather?
We know that many human activities lead to increasing levels of pollution of the air, water-bodies and soil. Do you think that isolating these activities to specific and limited areas would help in reducing pollution?
Write a note on how forests influence the quality of our air, soil and water resources.
What are the two things which are essential for all forms of life on the earth?
What is biosphere?
What are the physical components?
What is biotic component?
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