What is humus? What is its function in the soil?
Humus is the bits of decayed organisms present in the soil. It usually gives the soil a blackish colour.
Function. Humus is the major factor in deciding the soil structure because:
(i) it causes the soil to become more porous.
(ii) allows water and air to penetrate deep into the soil making available for the roots of the plants.
What are the physical components?
What is biotic component?
Does there exist any relationship between the climate and biotic components? If yes, explain with example.
What percentage of oxygen and nitrogen is present in the air?
Name the pollutants by which industries pollute air.
How is balance of carbon dioxide and oxygen maintained in the environment?
What is the percentage of carbon dioxide in the atmosphere of Venus and Mars?
What are the two main ways in which oxygen is consumed and carbon dioxide is produced?
What are the two ways in which carbon dioxide is fixed to keep its percentage almost constant?
What is the role of the atmosphere in climate control?
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