A:
(a) The four major domains of the Earth are:
- Lithosphere: the solid portion of the earth.
- Atmosphere: The airy portion of the earth.
- Hydrosphere: Water portion of the earth.
- Biosphere: The zone of contact between the land, air and water.
(b) The seven major continents of the Earth are:
- Asia
- Europe
- North America
- South America
- Africa
- Australia
- Antarctica
(c) The two continents that lie entirely in the Southern Hemisphere are:
- Australia
- Antarctica
(d) The different layers of atmosphere are:
- Troposphere
- Stratosphere
- Mesosphere
- Thermosphere
- Exosphere
(e) The Earth is called ‘Blue Planet’ because 71% of the Earth is covered with water and looks blue as seen from the outer space.
(f) The Northern Hemisphere is called the land Hemisphere because:
- Greater part of the landmass lies in the Northern Hemisphere. It is more than 70% of the total area.
- Waterbodies area is smaller in this hemisphere. It is only 30% of the total area.
(g) Importance of the Biosphere are as follows:
- It is in this zone where life exists.
- There are several species of organisms that vary in size from microbes and bacteria to huge mammals.
- All the living organisms are linked to each other and to the biosphere for the survival.