Category :
2nd Class
OUR ENVIRONMENT
FUNDAMENTAL
- Environment includes everything, i.e. vegetation, water, microorganisms, soil, rocks, atmosphere, etc.
- Our environment consists of both living and non-living things.eg. Atmosphere, sea, river, lakes, soil etc.
- Atmosphere means the sphere of air surrounding the earth. Mainly, there are four sub- systems called spheres, they are land (lithosphere), water (hydrosphere), living things (biosphere) and air (atmosphere).
- The atmosphere consists of four unique layers:
The troposphere (0-8 miles)
The stratosphere (8-30 miles)
The mesosphere (30-50 miles)
The thermosphere (50-120 miles)
- Atmosphere protects the life on the earth. Atmosphere has gases like nitrogen hydrogen, carbon dioxide, argon, helium and some more gases. It has 78% nitrogen, 21% oxygen and 1% other gases.
- Oxygen is the most important gas of atmosphere, as most of the living organisms inhale it.
- Seas are the natural source of water.
- Rivers are natural source of water. It is usually freshwater, flowing towards an etc. e.g. Ganges, Yamuna.
- Lakes are both natural and man-made. A lake is a still water body surrounded by from all sides. Lakes are a body of fresh or salt water of considerable size surrounded by land. E.g. Dal Lake, Wular Lake Etc.
- Soil is a natural resource made up of tiny particles of broken rock, mineral, clay and humus. Soil is an important ingredient for the survival of living organisms on earth.
- There are mainly three types of soil-sandy soil, clayey soil and loamy soil.
- Hard surface of the earth consists of rocks. The earth is made up of hard matter called rocks. They are many shapes, Sizes and colour.
- Various kinds of rocks are
(i) Granite \[\to \]It is used for making buildings and statutes
(ii) Marble \[\to \] It is used for making building and statutes
(iii) Sandstone\[\to \] These rocks are soft in nature.
Coal, slate, graphite, chalk is also soft.
