1. Answer the following questions briefly.
(a) What are the four major domains of the earth?
Answer– The four major domains of the earth are Lithosphere, Hydrosphere, Atmosphere, and biosphere.
(b) Name the major continents of the earth.
Answer– There are seven major continents. These continents are – Asia, Europe, Africa, North America, South America, Australia, and Antarctica.
(c) Name the two continents that lie entirely in the Southern Hemisphere.
Answer– The two continents that lie entirely in Southern Hemisphere are- Australia and South America.
(d) Name the different layers of the atmosphere.
Answer– The atmosphere is divided into five layers. These layers are the troposphere, the stratosphere, the mesosphere, the thermosphere, and the exosphere.
(e) Why is the earth called the ‘blue planet’?
Answer– The earth is called the blue planet because more than 71 percent of the earth is covered with water.
(f) Why is the Northern Hemisphere called the Land Hemisphere?
Answer– The Northern Hemisphere is called the land hemisphere because the greater part of the Earth’s landmass lies in the Northern Hemisphere.
(g) Why is the Biosphere important for living organisms?
Answer– The biosphere is the narrow zone of contact between land, water, and air. It provides the necessary environmental condition for survival. There are several species of organisms that vary in size from microbes and bacteria to huge mammals. All the living organisms including humans are linked to each other and to the biosphere for survival that’s why the biosphere is important for living organisms.
2. Tick the correct answer.
(a) The mountain range that separates Europe from Asia is
(i) the Andes (ii) the Himalayas (iii) the Urals
Answer: (ii) the Himalayas
(b) The continent of North America is linked to South America by
(i) an Isthmus (ii) a Strait (iii) a Canal
Answer: (i) an Isthmus
(c) The major constituent of the atmosphere by per cent is
(i) Nitrogen (ii) Oxygen (iii) Carbon dioxide
Answer: (iii) Carbon dioxide
(d) The domain of the earth consisting of solid rocks is
(i) the Atmosphere (ii) the Hydrosphere (iii) the Lithosphere
Answer: (ii) the Hydrosphere
3. Fill in the blanks:
(a) The deepest point on the earth is …………. in the Pacific Ocean.
Answer: The deepest point on the earth is Mariana Trench in the Pacific Ocean.
(b)The ………….. Ocean is named after a country.
Answer: The Indian Ocean is named after a country.
(c) The ………….. is a narrow contact zone of land, water, and air that supports life.
Answer: 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……………..
Answer: The continents of Europe and Asia together are known as Eurasia.
(e) The highest mountain peak on the earth is ……………
Answer: The highest mountain peak on the earth is Mount Everest.