1. Answer the following questions briefly.

Question a: What are the four major domains of the earth?
Answer:- The four major domains of the Earth are: lithosphere, hydrosphere, atmosphere and biosphere.

Question b:- Name the major continents of the earth.
Answer:- The seven major continents of the Earth are: Asia, Europe, Africa, North America, South America, Australia and Antarctica.

Question c:- Name the two continents that lie entirely in the Southern Hemisphere.
Answer:- The two continents that lie entirely in the Southern Hemisphere are – Australia and South America.

Question d:- Name the different layers of atmosphere.

Answer:-The atmosphere is comprised of five layers based on temperature. These layers are the Troposphere, Stratosphere, Mesosphere, Thermosphere and Exosphere.

Layers of the Atmosphere

Question e:Why is the earth called the ‘blue planet’?
Answer:- Planet Earth has been called the “Blue Planet” due to the abundant water on its surface. Earth is comprised of 79% of water and rest in land surface.

Question f:Why is the Northern Hemisphere called the Land Hemisphere?
Answer:- The Northern Hemisphere is called the Land Hemisphere because the greater part of Earth’s landmass lies in the Northern Hemisphere.

Question g:- Why is the Biosphere important for living organisms?
Answer:– Biosphere is important for living organisms because it is termed as the zone of life on earth. The biosphere can also be referred to the zone of life on Earth. It cannot be affected by things such as solar and cosmic radiation, and is self-regulating.

2. Tick the correct answers.

(a) The mountain range that separates Europe from Asia is
(i) the Andes
(ii) the Himalayas
Ans. (iii) the Urals

(b) The continent of North America is linked to South America by
Ans. (i) an Isthmus
(ii) a Strait
(iii) a Canal

(c) The major constituent of atmosphere by per cent is
Ans. (i) Nitrogen
(ii) Oxygen
(iii) Carbon dioxide

(d) The domain of the earth consisting of solid rocks is
(i) the Atmosphere
(ii) the Hydrosphere
Ans. (iii) the Lithosphere

(e) Which is the largest continent?
(i) Africa
Ans. (ii) Asia
(iii) Australia

3. Fill in the blanks

(a) The deepest point on the earth is  Mariana Trench in the Pacific Ocean.
(b) The Indian Ocean  Ocean is named after a country.
(c) The  Biosphere  is a narrow contact zone of land, water and air that supports life.
(d) The continents of Europe and Asia together are known as  Eurasia.
(e) The highest mountain peak on the earth is  Mt. Everest . (8,848 meters)