Chapter 3: The Earth and its Living World
Can you tell?
(1) Where do you get water from?
(2) Where do we lay the foundation of buildings?
(3) What need do we meet through breathing?
(4) From where does the earth get light and heat?
Use your brain power!
(1) In which layer of the atmosphere do we see the rainbow?
(2) Mountaineers carry oxygen in cylinders when they climb mountains that are more than 5000m high. What could be the reason for that?
1. What’s the solution?
Dark patches appear on the skin after exposure to the sun.
2. Use your brain power!
(a) Why are micro-organisms important?
(b) Think about all the foodstuffs obtained from the sea. Find more information and write ten lines about them.
3. Answer the following questions.
(a) What are clouds made of ?
(b) What is meant by ‘biosphere’?
(c) Make a list of the landforms you see in your surroundings and give a description of any two of them.
4. In the following sentences, underline the words that refer to landforms.
(a) Anil lives at the foot of a hill.
(b) Ria lives in the plateau region.
5. Write a note about the following.
(c) The water cycle
6. Give two examples of each.
(a) Weather-related events
(b) Sources of water
7. Draw a labelled diagram showing the water cycle.
Activity Find out more information about the different layers of the atmosphere.
Fill in the blanks:
1. On the surface of the earth, we find land in some places and ___________ in others.
2. The earth is surrounded by the ___________.
3. There are living things on land, in water and in the ___________.
4. The ___________ is the cause of many natural processes on the earth.
5. Water, land and air constitute envelopes of the earth, namely, the ___________, ___________ and atmosphere.
6. The earth’s crust is hard and is mainly made of ___________.
7. All these land features are a part of the earth’s ___________.
8. A vast continuous stretch of land is called a ___________.
9. The land on earth is divided into ___________ continents.
10. The seven continents are __________________________________________________________________.
11. ___________ is the largest continent and ___________ the smallest continent.
12. Two-thirds of the earth’s surface is covered with ___________.
13. Most of this water is in the ___________.
14. Ocean water is ___________.
15. The five oceans are __________________________________________________________________.
16. The land along the margins of an ocean is called the ___________region.
17. Rivers which join to make a bigger river are called its ___________.
18. A river that cascades down a sudden drop forms a ___________.
19. All rivers eventually flow into the ___________.
20. A water body formed by water collecting naturally in a low-lying area of land is called a ___________.
21. The huge blocks of ice floating in the sea are called ___________.
22. Water stored in the underground layers of rock is called ___________.
23. Many lakes and wells get water from underground ___________.
24. The water or ice that occupies the earth’s surface, groundwater and the water vapour in the atmosphere together form the earth’s ___________.
25. The envelope of air around the earth is called the ___________.
26. As we go higher from the surface of the earth, the air in the atmosphere becomes ___________.
27. The atmosphere consists of a mixture of gases, namely, __________________________________________________________________.
28. The layers of the atmosphere are named as the __________________________________________________________________.
29. The layer that extends from the earth’s surface to a height of about 13 km is called the ___________.
30. Almost all the water vapour in the atmosphere is contained in the ___________.
31. All weather-related phenomena such as formation of clouds, rain, fog, winds and storms take place in the ___________.
32. Aeroplanes fly in the higher parts of the ___________.
33. Beyond the troposphere, up to a height of about 50 km from the earth is the layer called the ___________.
34. In the lower part of the stratosphere, there is a layer of a gas called ___________.
35. ___________ rays coming from the sun are harmful for living things.
36. The ___________ layer absorbs the ultra violet rays and protects the living world.
37. Water on the earth ___________ continuously due to the heat of the sun.
38. The processes of evaporation, condensation and rainfall go on in a continuous cycle and known as the ___________.
39. The ___________ bear is seen only in the snowbound polar regions.
40. Zebras are found in ___________ and kangaroos are found only in ___________.
41. ___________ exist in the lithosphere, hydrosphere and atmosphere.
42. All animals, plants and micro-organisms are ___________ on one another.
43. The water cycle on earth goes on ___________.
44. Living things and all the parts they occupy are together called the ___________.
Answer the following
1. Name the three spheres of the earth.
2. What is biosphere?
3. What is a continent?
4. Name the seven continents
5. Which is the largest and which is the smallest continent?
6. What are landforms? Name the different landforms.
7. Name the five oceans.
8. What is a coastal region?
9. Name the different water bodies formed along the coast.
10. Name the different streams of water.
11. What are tributaries?
12. How are waterfalls formed?
13. What is a lake?
14. What is a glacier?
15. What are icebergs?
16. What is ground water?
17. From where do lakes and wells get water?
18. What is hydrosphere?
19. What is atmosphere?
20. Name the layers of the atmosphere.
21. Why is the ozone layer important?
22. What is a water cycle?
23. What is lithosphere?
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