Ratna Sagar Geography Solutions for Class 6 Social science Chapter 5 - Major Domains Of The Earth

Answer:

The correct answer is option (a).

Explanation: Following are the three domains responsible for the existence of life on the Earth:

• Atmosphere
• Hydrosphere
• Lithosphere

Answer:

The correct answer is option (c).

Explanation: There are seven continents on the Earth. Among these seven continents, Asia is the largest in terms of population and area.

Answer:

The correct answer is option (d).

Explanation: The Urals separate the continents of Europe and Asia. These high mountain ranges are located on the east of Europe and on the west of Asia.

Answer:

The correct answer is option (c).

Explanation: The continent of North America is linked with South America by the Isthmus of Panama. It is a narrow land mass between the Pacific Ocean and the Caribbean Sea that separates the two continents.

Answer:

The correct answer is option (b).

Explanation: The Equator divides the continent of Africa in almost two equal halves. Thus, the African continent lies on both sides of the Equator.

Answer:

The correct answer is option (a).

Explanation: ​Ferdinand Magellan, a European sailor, was the first to sail across the Pacific Ocean in the year 1520. He named the ocean 'Pacific' because the winds that blew above it were very gentle and mild.

Answer:

​The correct answer is option (b).

Explanation: Water vapour in the atmosphere is confined only to its lower layer, i.e. troposphere. This is the reason all weather phenomena occur only in this layer.

Answer:

The correct answer is option (d).

Explanation: The biosphere is the zone where the lithosphere, the hydrosphere and the atmosphere interact with each other. This narrow sphere of the Earth supports life. The asthenosphere lies below the crust of the Earth.

Answer:

1. Asia and Europe are together known as Eurasia.

Explanation: Europe is seen as the landmass extending towards the Asian continent in its west direction. Europe and Asia together are known as Eurasia.

2. The highest mountain peak in Europe is​ Mount Elbrus.

Explanation: Europe is a continent known for high mountains; Mount Elbrus located in Caucasus is the highest mountain peak of Europe.

3. La Plata river basin in South America is called the​ Gran Chaco.

Explanation: The South American continent is mostly drained by three river systems, i.e. Orinoco, Amazon and La Plata. The La Plata river basin in South America is known as the Gran Chaco. 

4. The Indian Ocean is known as 'half an ocean'.

Explanation: Since the Indian Ocean is separated from the Arctic Ocean by the Asian continent, it does not open in the north direction. This is the reason it is referred to as 'half an ocean'.

Answer:

1. The domain of the Earth represents three states of matter, which are as follows:

• Lithosphere
• Hydrosphere
• Atmosphere

• The Kalahari
• The Sahara
• The Namibian Desert

• Asia
• Europe
• North America

• Pacific Ocean
• Atlantic Ocean
• Arctic Ocean
• Indian Ocean

• Nitrogen - 78%
• Oxygen - 21%
• Argon - 0.93%
• Carbon dioxide - 0.03%
• Water vapour
• Others gases like argon, helium and ozone

Answer:

1. The given statement is false.

Explanation: The Great Barrier Reef is formed by the corals; it is located along the northeastern coast of the Australian continent.


2. ​The given statement is true.

Explanation: The Caribbean Islands off the Gulf of Mexico are called West Indies. The adjoining water body is known as the Caribbean Sea.


3. ​​The given statement is true.

Explanation: The Andes are the longest unbroken chain of mountains in the world. Mount Aconcagua is the highest mountain peak in the Andes mountains.


4. ​The given statement is false.

Explanation: The Pacific Ocean was named Pacific by Ferdinand Magellan. He named it so because of the peaceful winds blowing over the ocean.

Answer:

The correct match is as follows:
 

Answer:

1.

Answer:

1. Lithosphere: It is the domain of the Earth that is composed of the solid mass of the Earth's surface and includes rocks and soil on its crust. It covers around 29% of the Earth's surface. It is divided into seven continents Asia, Africa, Antarctica, North America, South America, Europe and Australia.

2. Hydrosphere: The availability of water is a unique feature of the Earth. The domain of the Earth's surface comprising water, including oceans, seas, rivers and lakes, is known as the hydrosphere. It covers 71% of the Earth's surface.

3. Atmosphere: The air around the Earth's surface till a height of 1,600 kilometres is known as the atmosphere. It is composed of gases like nitrogen, oxygen, ozone and carbon dioxide and water vapour. It is an essential factor for the existence of life on the Earth, as it prevents harmful rays of the Sun from reaching the surface of the Earth.

4. Biosphere: It is a narrow zone of the Earth's surface where different domains like air, water and land interact with each other to support life. 
 
5. Antarctica: The continent is completely covered with ice; hence, it is known as the white continent. It is located near the South Pole and provides avenues for weather-related discoveries. This is the reason it is also known as the continent of science.

6. Pacific Ocean: This ocean was discovered by Ferdinand Magellan. It was named so because of the presence of steady, calm and swift winds around it. It is the largest and deepest ocean in the world. Also, more than 75% of the active volcanoes are found in the land bordering the Pacific.

7. Atlantic Ocean: This ocean is roughly half the size of the Pacific Ocean. It is the busiest sea route owing to its strategic location. It is located between North and South America on the west side and Europe and Africa on the east side. 

8. Indian Ocean: It is the only ocean that has been named after a country. The reason is that India is strategically located to its north and had a great role in international trade via sea in ancient times. It is bounded on three sides by three continents, i.e. Africa on the east, Asia on the north and Australia on the west.

9. Troposphere: It is the lowest layer of the Earth's atmosphere and extends to a height of around 18 kilometres at the Equator and 8 kilometres at the poles. All weather phenomena occur in this layer only, as it contains almost 90% of the atmospheric air. In this layer, temperature decreases at the rate of 1^oC per 165 metres.

Answer:

1. The largest continent on the Earth is Asia. It is located in the Northern Hemisphere.

2. Mount Everest is the highest mountain peak in the world. It is situated in Nepal at a height of 8,848 metres from the sea level.

3. Australia is the smallest continent in the world; it is located in the Southern Hemisphere. 

4. The Andes in South America is the longest unbroken chain of mountains, with Mount Aconcagua as its highest peak.

5. Oceans are deep and vast bodies of water. The average depth of oceans is 3,800 metres.

6. The Mariana Trench is the deepest trench at a depth of 11,022 metres; it is located towards the east of the Pacific Ocean.

7. The Pacific Ocean is the largest and deepest ocean in the world. It covers the area that is more than the total area of all the continents taken together.

8. The biosphere is the fourth domain of the Earth. It is the zone where land, air and water interact with each other to support life.

Answer:

The names of continents in increasing order of their size are as follows:

1. Australia 
2. Europe
3. Antarctica
4. South America
5. North America
6. Africa
7. Asia 

Answer:

The names of the oceans in order of their increasing size are as follows:

1. The Arctic Ocean 
2. The Indian Ocean
3. The Atlantic Ocean
4. The Pacific Ocean 

Answer:

The atmosphere is composed of several odourless, tasteless, colourless gases. The cover of the air that extends to a height of around 1,600 kilometres from the Earth's surface is known as the atmosphere. The composition of the air in the atmosphere is as follows:

• Nitrogen - 78%
• Oxygen - 21%
• Argon - 0.93%
• Carbon dioxide - 0.03%
• Water vapour
• Others gases like argon, helium and ozone

Answer:

Following are the layers of the atmosphere:

• Troposphere
• Stratosphere
• Mesosphere
• Thermosphere
• Exosphere
• Ionosphere

Answer:

The biosphere is a narrow zone where land, air and water interact with each other to support several forms of life. The biotic or living elements of the biosphere are plants, animals, human beings and microbes. They are dependent on one another for their existence. The abiotic or non-living components of the biosphere include rocks and minerals.

Answer:

Important physical features of all continents are given below.

1. Africa: This continent has a lot of plateaus but no high mountains. A large part of the continent is covered with deserts, e.g. the Sahara Desert, the Kalahari Desert and the Namibian Desert. It also has thick forests in the equatorial region.

2. Asia: It is known as the continent of extremes because in this continent, the highest peak and the lowest point of Earth's surface are found, i.e. Mount Everest, which is the highest peak in the world, and the Mariana Trench, which is the lowest point of the Earth's surface. All kinds of topographic features are found in this continent.

3. Australia: It is a land of plateaus with few dispersed low mountain ranges. The Great Barrier Reef is an important feature of the continent, which is formed by the corals.

4. Europe: It is the only continent that is both populous and prosperous. It is a land of high mountains. Finland in Europe has more than 50,000 lakes; the continent is extremely beautiful.

5. North America: It is a land with extensive plains, mountain ranges and ancient plateaus. Grasslands are an important feature of this place. For example, the Prairies are important grasslands of this region.

6. South America: The Andes is the longest unbroken chain of mountains in the world. Apart from the mountains, almost half of the continent is covered with lowlands and river basins.

7. Antarctica: It has some mountain ranges and vast plateaus. It is completely covered with ice. Therefore, it is also known as the white continent.

Answer:

The importance of oceans for human beings can be understood with the help of the following points:

• They are a storehouse of a large number of minerals and energy resources.
• They provide a large number of fish and other marine animals used as food in large quantities.
• They play an important role in causing humidity in the atmosphere; this ultimately leads to rain.
• They act as important trade routes.
• They act as a link between several continents.
• They are an important source of common salt.
• They help in regulating climate by storing carbon; they also have a stabilising influence on the water cycle.
• Tidal energy is of great potential in the present era of energy crisis.

Answer:

The importance of the atmosphere can be understood with the help of the below-mentioned points:

• The atmosphere has gases like oxygen and nitrogen that are essential for the existence of life on the Earth.
• The ozone layer in the atmosphere prevents harmful ultraviolet radiations from reaching the Earth's surface.
• The presence of gases ensures that the temperature of the Earth's surface does not reach extremes during day and night.
• The atmosphere is responsible for the occurrence of phenomena like condensation, evaporation and precipitation.
• The transmission of sound waves from one place to another is possible only because of the presence of air in the atmosphere.

Answer:

In ancient times, when the population was small, people were directly dependent on the nature for their needs. But with increasing population, the needs and requirements of the people started increasing day by day. This started taking a huge toll on the ecological balance of nature. Human beings ended up altering the delicate balance of nature through the following ways:​

• By large-scale mining of minerals and other natural resources
• By large-scale burning of fossil fuels like coal, petroleum, etc.
• By illegally dumping wastes in oceans and water bodies
• By rampant clearing of forest lands 

Answer:

The biosphere is a narrow zone of Earth's surface where the interaction between land, water and air takes place. It supports life on the Earth. Here, the three domains of the Earth, i.e. lithosphere, atmosphere and hydrosphere, come in contact with each other and support life. The elements of the biosphere are plants, animals, human beings and microbes, which constitute its biotic components. All these elements are interlinked in one way or the other and support life. Since we are dependent on the biosphere for our existence, it is our duty to maintain its balance. The abiotic components of the biosphere are rocks and minerals.

Answer:

The Earth is also known as the blue planet because of the presence of water on it. It is the only planet in the universe that has water. When seen from the outer space, the Earth appears blue because of the presence of water on it. This is the reason it has been called the blue planet. Seventy-one percent of the Earth's surface is covered with water. Out of this, ninety-seven percent of water is concentrated in the oceans, which are the Pacific Ocean, the Atlantic Ocean, the Arctic Ocean and the Indian Oceans. The remaining water is found in rivers, icecaps, glaciers, etc.

Answer:

Antarctica is located near the South Pole. It is completely covered with ice; hence, it is known as the white continent. Since it is very unapproachable and harbours extreme weather conditions, not much is known about it. It was first discovered in 1820. The continent provides avenues for scientific studies related to different fields. Thus, many countries have established scientific study centres here. It also provides opportunities to study weather. This is the reason it is also known as the continent of science.

Answer:

The Earth is not directly heated by the rays of the Sun; it is heated by the reflection of the sunrays from its own surface. The surface of the Earth reflects the sunrays that fall upon it, causing an increase in the temperature of the surrounding air, but with increase in height, the distance from the surface increases and hence heating decreases. Thus, the air temperature decreases with increase in height. There is a decrease of 1 °C in temperature with an increase of 165 metres.