These DAV Class 6 SST Book Solutions and DAV Class 6 SST Chapter 5 Question Answer – The Realms of the Earth are thoughtfully prepared by experienced teachers.
DAV Class 6 SST Ch 5 Question Answer – The Realms of the Earth
DAV Public School Class 6 SST Chapter 5 Question Answer – The Realms of the Earth
Something To Know
A. Tick (✓) the correct option.
Question 1.
Which one of the following is an old mountain?
(a) The Himalayas
(b) The Aravalii Range
(c) The Andes
(d) The Alps
Answer:
(b) The Aravalii Range
Question 2.
How much surface of the earth is covered by oceans?
(a) 29%
(b) 71%
(c) 60%
(d) 80%
Answer:
(b) 71%
Question 3.
The largest ocean of the world is
(a) Indian Ocean
(b) Pacific (Ocean
(c) Arctic Ocean
(d) Atlantic Ocean
Answer:
(b) Pacific (Ocean
Question 4.
Which continent is the rpost advanced and economically developed continent?
(a) Asia
(b) Norib. America
(c) Australia
(d) Europe
Answer:
(d) Europe
Question 5.
Which one of the following gases has the largest volume in the atmosphere?
(a) Nitrogen
(b) Oxygen
(c) Ozone
(d) Cay bon dioxide
Answer:
(a) Nitrogen
B. Fill in the blanks.
1. is a narrow belt or zone of the earth where all forms of life exist.
2. An envelope of the air surrounding the earth is called
3. is the upper surface of the earth consisting of rocks.
4. A highly elevated land from the surroundings with very steep slopes is known as
5. An upland with rugged surface is called
Answer:
1. Biosphere
2. atmosphere
3. Lithosphere
4. mountains
5. plateau.
C. Match the following:
| 1. It separates | (a) Asia Europe and Asia |
| 2. It joins North | (b) Oxygen America with South America |
| 3. The largest | (c) Isthmus of continent of the Panama world |
| 4. It helps in burning | (d) Antarctica the Southern |
| 5. Continent in | (e) Ural Hemisphere mountain and Ural river |
Answer:
| 1. It separates | (d) Antarctica the Southern |
| 2. It joins North | (c) Isthmus of continent of the Panama world |
| 3. The largest | (a) Asia Europe and Asia |
| 4. It helps in burning | (b) Oxygen America with South America |
| 5. Continent in | (d) Antarctica the Southern |
D. Answer the following questions in brief.
Question 1.
Name the four realms of the earth.
Answer:
Lithosphere, atmosphere, hydro¬sphere and biosphere.
Question 2.
Which four gases constitute only one per cent of the total volume of the atmosphere?
Answer:
Carbon dioxide, organ, hydrogen and helium.
Question 3.
Which continent is not inhabited by the people and why?
Answer:
Antarctica is not a habitat by the people because it is covered with very thick sheets of ice and snow.
Question 4.
Why is the earth known as a unique planet’?
Answer:
Our earth is a unique planet because it is the only planet where life is known to exist. This is because the earth has all the favourable conditions needed for the existence of life, i.e., moderate temperature, suitable atmosphere and presence of water.
Question 5.
Name three major landforms on the land surface.
Answer:
Mountains, plains and plateaus.
E. Answer the following questions.
Question 1.
What are plains? Explain briefly the formation of plains.
Answer:
Plains are relatively low-lying flat land. The slope of plains are gentle and their average height is between 100 and 200 metres above sea level. Most of the plains in the world have been formed by rivers and their tributaries. These rivers and their tributaries carry away large volume of silt and sediments from the mountains and deposit them in the low-lying areas to form plains.
Question 2.
Give a brief account of the plateaus of the world.
Answer:
There are several plateaus in the world. The plateau of Tibet is the highest one and, therefore, known as the Roof of the world. Its average height is about 5000 metres above sea level. The Deccan and Ladakh plateaus in India, the Arabian plateau and the Brazil plateau are some other plateaus of the world.
Question 3.
Name the two gases of the atmosphere. Write the significance of each.
Answer:
Nitrogen and oxygen are the main gases of the atmosphere. 78% volume of gas in the atmosphere is nitrogen. It is essential for the growth of living organisms. Oxygen is about 21% of the total volume. It is the breath of life. All living things breathe in oxygen to live. Aquatic animals get oxygen from water. Also it helps things to burn.
Question 4.
What is meant by hydrosphere? Briefly explain the importance of the hydrosphere.
Answer:
Hydrosphere refers to the water bodies that are found on the earth’s surface, below the earth’s surface and in the air. More than 71% of the earth is covered with water. This water is found in all its forms-ice, water and water vapour. Running water in the oceans and rivers and in lakes, ice in glaciers, underground water and water vapour in the atmosphere all constitute a hydrosphere.
Hydrosphere is an important domain of the earth because it makes our life possible on it. We can not imagine life without water. This is also essential for the existence of the plant kingdom. Whatever greenery we see on the earth, it is only due to water.
Question 5.
How are human activities responsible for causing ecological imbalance?
Answer:
The human population is increasing fast. As a result, more space is required for different human activities such as agriculture, industiy and urbanisation. Man is destroying the forests carelessly and exploiting the resources to meet his selfish needs. He does not bother for his future generation and is expanding the area of agriculture and industiy. As a result of his thoughtless activities, several problems have emerged. Soil erosion, floods and pollution air and water are some of them. Human beings must stop interference to maintain a balance between plants and animals.
Value-Based Question
House sparrow is gradually vanishing from urban scenario. Our urban lifestyle is responsible for it. Electromagnetic radiation from the mobile towers, shortage of nesting spaces, shortage of insect food, decline of native plants, changes in the architectural designs of buildings, unleaded petrol and use of insecticides are some of the reasons for vanishing of the bird. Human beings are a part of the ecosystem. They do not have a right to disturb the ecological balance. We all have to take intiative to save sparrows by enhancing awareness about their life and habitat.
- Why some people have become so insensitive towards other species?
- Like the house sparrow, which other birds or animals living around us in the residential areas are on the verge of extinction?
- Suggest any three effective measures to protect the endangered species.
Answer:
Do yourself.
Map Skill
Shade and label different continents as well as major oceans on an outline map of the world.
Answer:
Something To Do
Question 1.
Draw a diagram of the biosphere showing its diversity.
Answer:
Question 2.
Prepare a chart depicting different landforms on the earth and label them.
Answer:
Do yourself.
Question 3.
Prepare a chart showing the interdependence of plants, animals and micro-organisms.
Answer:
Do yourself.
DAV Class 6 Social Science Chapter 5 Question Answer – The Realms of the Earth
A. Tick (✓) the correct option.
Question 1.
What per cent of the total crust of the earth do continents form?
(a) 21
(b) 29
(c) 33
(d) 71
Answer:
(b) 29
Question 2.
The largest continent is
(a) Asia
(b) Africa
(c) Australia
(d) Europe
Answer:
(a) Asia
Question 3.
Europe is located to the of Asia.
(a) east
(b) west
(c) north
(d) south
Answer:
(b) west
Question 4.
Australia lies in the
(a) Southern Hemisphere
(b) Northern Hemisphere
(c) Eastern Hemisphere
(d) Western Hemisphere
Answer:
(a) Southern Hemisphere
Question 5.
The Ural mountains are located in
(a) USA
(b) Canada
(c) Russia
(d) India
Answer:
(c) Russia
Question 6.
The Deccan plateau is found in
(a) Brazil
(b) India
(c) Canada
(d) Australia
Answer:
(b) India
Question 7.
The areas most suitable for farming are
(a) hills
(b) plateaus
(c) plains
(d) all of these
Answer:
(c) plains
Question 8.
The Andes are the mountain ranges located in
(a) North America
(b) South America
(c) Australia
(d) Europe
Answer:
(b) South America
Question 9.
The deepest of all oceans is the
(a) Atlantic
(b) Indian
(c) Pacific
(d) Arctic
Answer:
(c) Pacific
Question 10.
The domain of the earth consisting of solid rocks is
(a) lithosphere
(b) atmosphere
(c) hydrosphere
(d) biosphere
Answer:
(a) lithosphere
B. Very Short Answer Type Questions
Question 1.
What is the average height of the land- mass of the earth above the sea level?
Answer:
It is about 700 metres.
Question 2.
What per cent of the total landmass does Europe cover?
Answer:
Europe covers 7 per cent of the total landmass.
Question 3.
Which is the second largest continent of the world?
Answer:
Africa.
Question 4.
Why was Africa called the dark continent?
Answer:
Because people of other parts did not know much about Africa.
Question 5.
Name the narrow piece of land which joins Africa with Asia in the east.
Answer:
Suez Isthamus.
Question 6.
What do you know about Mariana Trench?
Answer:
It is the deepest point of on the earth which lies in the Pacific Ocean.
Question 7.
Which are the two maj or economically developed countries of North America?
Answer:
Canada and USA.
Question 8.
Which continent is known as the island continent?
Answer:
Australia.
Question 9.
Give two examples of the old mountains.
Answer:
The Aravalli range in India and the Appalachians in USA.
Question 10.
Give two examples of the young mountains.
Answer:
The Himalayas in Asia and the Alps in Europe.
Question 11.
Which is the highest plateau in the world? What is it known as?
Answer:
The plateau of Tibet is the highest plateau in the world. It is known as the roof of the world.
Question 12.
Which enjoys an ideal climate – a plain area or a mountainous area?
Answer:
A plain area enjoys an ideal climate.
Question 13.
What is the height of Mount Everest? Where is it located?
Answer:
The height of Mount Everest is 8848 metres above sea-level. It is located in Nepal.
Question 14.
When does the density of air decreases?
Answer:
When we go higher, the density of air decreases.
Question 15.
Which ocean resembles the letter ‘S’ in shape?
Answer:
The Atlantic Ocean.
Question 16.
Which ocean is bounded by the continents of Asia, Africa and Australia?
Answer:
The Indian Ocean.
Question 17.
In which form is water present in polar regions and on high mountains?
Answer:
Water is present in the form of ice sheets in polar regions and on high mountains.
Question 18.
What are the major domains of the earth?
Answer:
The major domains of the earth are –
- Lithosphere
- Hydrosphere
- Atmosphere
- Biosphere
Question 19.
What is atmosphere?
Answer:
The atmosphere is the vast expanse of air surrounding the earth on all sides. It contains several gases. It gives us air to breathe.
Question 20.
What is the range of the biosphere?
Answer:
From tiny microbes and bacteria to huge mammals.
Question 21.
Name two main gases of the atmosphere which constitute about 99 per cent of the total volume of the atmosphere.
Answer:
Nitrogen and Oxygen.
Question 22.
Where is the density of air found to be the highest?
Answer:
The density of air is found to be the highest near the earth’s surface.
Question 23.
Why is the earth known as the Watery Planet’?
Answer:
Water covers about two-thirds of the total surface of the earth. Hence, the earth is known as the Watery Planet’.
C. Short Answer Type Questions
Question 1.
The biosphere is the domain of life. Explain.
Or
Why is biosphere called the realm of life?
Answer:
The biosphere is a narrow zone of the earth where land, water and air interact with each other to support life. It is in this zone that life exists. There are several species of organisms varying in size from microbes and bacteria to large mammals. All plants, animals and micro-organisms live together in their physical environment and interact with each other. They are interdependent for their survival.
Question 2.
Give three features of mountains.
Answer:
Three features of mountains are:
- They are natural elevations of the earth’s surface. The uppermost parts of mountains form peaks.
- Most of the mountains are arranged in a line called a range, which has a series of peaks and valleys.
- The climate of mountains is harsh, which makes life a little bit difficult there.
Question 3.
How is oxygen and ozone important to us?
Answer:
Oxygen is the breath of life. It makes our life possible on the earth. We can’t live without it. The ozone layer in the atmosphere protects all forms of life on the earth from the harmful radiation of the sun.
Question 4.
Give a brief account of the plains of the world. Why are plains densely populated?
Answer:
Plains are vast stretches of flat land. The Northern Plains of India and Pakistan have been formed by the Indus, Ganga and Brahmaputra rivers and their tributaries. Other important plains of the world are the Great China plain, the Egyptian plain and the plains of Iraq. Plains are densely populated regions because they have fertile soil which is suitable for cultivation. They have abundant supply of water and an ideal climate. It is easy to build houses, roads, etc. in plains.
D. Long Answer Type Questions
Question 1.
How many continents are there? Describe them briefly.
Answer:
There are seven continents-Asia, Africa, Europe, North America, South America, Australia and Antarctica.
1. Asia. It is the largest continent which covers about one-third (29.6%) of the total land area of the earth. It lies in the Eastern Hemisphere. In the north, it touches the Arctic Ocean. In the extreme south, the equator passes through some parts of this continent. It is bounded by the Pacific Ocean in the east and in the west, Ural Mountains and Ural River separate it from Europe.
2. Europe. It is located to the west of Asia. It is much smaller in area than Asia. It covers 7% of the total landmass. The continent is bound by water bodies on three sides.
3. Africa. It is the second largest continent after Asia. It is separated from Europe by the Mediterranean Sea in the north. A very narrow piece of land known as Suez Isthamus, joins it with Asia in the east. The Atlantic Ocean is on its west and the Indian Ocean is on its east. The Equator passes through the middle of the continent. A large part of Africa lies in the Northern Hemisphere. It is the only continent through which the Tropic of Cancer, the Equator and the Tropic of Capricorn pass.
4. North America. It is the third largest continent and lies in the Northern Hemisphere. It is linked to South America by a very narrow strip of land called Isthamus of Panama. The Atlantic Ocean lies to the east and the Pacific Ocean to the west of the continent. The Arctic Ocean makes its boundary in the north.
5. South America. It lies mostly in the Southern Hemisphere. It is surrounded by Atlantic Ocean in the east and the Pacific in the west. The world’s largest river, the Amazon, flows through this continent.
6. Australia. It is the smallest continent, k lies completely m the Southern Hemisphere. It is surrounded by the Indian ocean in the west and die Pacific Ocean in the easi (w’i) Antarctica. It lies completely in the Southern Hemisphere, h is stretched around the South Pole upto the Antarctic hole, ‘this continent is covered with very thick sheets of ice and snow Permanent human settlement is not found here. Scientists of some counhies including India have establisiied their research centres here
Question 2.
Give a detailed description of all the four oceans of the world
Answer:
About 71 per cent of the total surtace of the earth is covered with waLer. This vast expanse of waiei is in die form of foui oceans-the Pacific, die Atlantic, the Indian and i.he Arctic.
1. The Pacific Ocean. It is the largest ocean and is spread oTei one-Liard of the earth. On the west, a is bounded by Asia and Australia and on the east, by North America and South America, Mariana Trench, the deepest part of the earth, lies in the Pacific Ocean. This ocean is circular in shape.
2. The Atlantic Ocean. It is the second largest ocean after the Pacific Ocean. It is ‘S’ shaped. It covers about one- sixth of the total surface of the earth. It is flanked by the North and South Americas on the western side and
Europe and Africa on the eastern side.
3. The Indian Ocean. It is the only ocean named after a country, that is India. It is smaller than the pacific and the Atlantic Ocean. It is
bounded by the continents of Asia, Africa and Australia. The shape of this ocean is triangular.
4. The Arctic Ocean. It is located within the Arctic circle and surrounds the North Pole. It is connected with the Pacific Ocean by a narrow stretch of shallow water known as Berring Strait. This ocean remains frozen for most part of the year.
Question 3.
Differentiate between the following:
(a) Mountain and Plateau
(b) Young mountains and Old mountains.
Answer:
(a) A mountain may have a small summit and a broad base but a plateau is a flat-topped table land standing above the surrounding area. Plateaus generally have better means of transport as compared to the mountains.
(b) The young mountains were formed during the recent phase of mountain building, about 25 million years ago. They are veiy high and have sharp peaks. The old mountains, on the other hand, are those which have been worn down by the forces of nature and do not have sharp peaks.