Page 1 - 2. Lesson notes- Air, Rain and Air pollution
P. 1
SAI International School
Subject- Biology
Chapter- Natural Resources
Subtopic- Air, Rain and Air pollution
Module- 31
Lesson Notes
Resource – A Resource is a stock or supply of something useful. Resources can be manmade
or Natural.
Natural Resources – A Resource which exists in nature is called a Natural Resource. It is not
produced by any human being; rather it is available in nature itself. Human beings and other
animals depend upon these resources for their existence. It include water (seas and fresh
water), land, soils, rocks, forests (vegetation), animals (including fish), fossil fuels and minerals.
Natural Resources present on the earth are:
• Air – The atmosphere which contains different gases such as Oxygen, Nitrogen and
carbon dioxide which are required for the survival of life on earth.
• Water – The hydrosphere which covers almost 75% of the Earth surface. It is a home to
an abundance of animals and plants and is also required for the survival of life on earth.
• Land – The upper crust of the earth is called Lithosphere where different kinds of soils
are found which are necessary for the growth of plants and are a home to several
vitamins and minerals.
Air
composition of air: Mixture of gases like oxygen, carbon dioxide, nitrogen, and water vapor.
Use of oxygen: Oxygen plays a critical role in respiration to produce energy for metabolisms
of most living things.
We humans, along with many other creatures, need oxygen in the air we breathe to stay alive.
Plants both use oxygen (during respiration) and produce it (via photosynthesis).
Used for the burning of fuel.
Use of Carbon dioxide :
1. Green plants convert carbon dioxide into glucose in the presence of sunlight.
2. Many marine animals use carbonates dissolved in seawater to make their shells.
Role of atmosphere in climate control :
• The atmosphere prevents the sudden increase in temperature during the daylight hours.
And during the night, it slows down the escape of heat into outer space.
