Q: Answer the following questions briefly:
a) What are the four major domains of the earth ?
Ans: The four major domains of the earth are Lithosphere, Hydrosphere, Atmosphere and Biosphere.
b) Name the major continents of the earth.
Ans: The major continents of the earth are Asia, Europe, Australia, North America, South America, Antarctica and Africa.
c) Name the two continents that lie entirely in the Southern Hemisphere.
Ans: Australia and Antarctica are the two continents that lie entirely in the Southern Hemisphere.
d) Name the different layers of atmosphere.
Ans: The different layers of atmosphere are troposphere, stratosphere, mesosphere, thermosphere and exosphere.
e) Why is the earth called the ‘blue planet’ ?
Ans: The earth is called the ‘blue planet’ because more than 71 per cent of the earth is covered with water.
f) Why is the Northern Hemisphere called the Land Hemisphere ?
Ans: As greater part of the land masses lie in the Northern Hemisphere, it is called Land Hemisphere.
g) Why is the biosphere important for the living organisms ?
Ans: The biosphere provides a contact between the land, water and air which is important for the survival of living organisms. Thus, biosphere is important for the living organisms.