problem 1:

How does land degradation happens? prepare its unfavourable effects.

problem 2:

prepare down the economic significance of forest.

problem 3:

What do you understand by the term ecological succession?

problem 4:

Make a distinction between food chain and food web with appropriate illustrations.

problem 5:

Illustrate out the term biological oxygen demand and chemical oxygen demand. prepare down its significance in environmental studies.

problem 6:

Illustrate out the term hydrological cycle. Provide the pictorial representation of the hydrological cycle.