Major Domains Of The Earth - Class 6 Geography - Extra Questions

The density of the atmosphere varies with height. It is maximum at sea level and decreases rapidly as we go up. That is why the climbers experience problems in breathing due to this decrease in the density of air. They have to carry with them oxygen cylinders to be able to breathe at high altitudes.

The Biosphere is the narrow zone where we find land, water and air together, which contains all forms of life.

Biosphere is important for living organisms because it is here that three essential elements of life (land, water and air) are found. 

The atmosphere exerts pressure on the earth. This varies from place to place. Some areas experience high pressure and some areas low pressure. Air moves from high pressure to low pressure. Moving air is known as wind.

The atmosphere is composed mainly of nitrogen and oxygen, which make up about 99 percent of clean, dry air. Nitrogen 78 percent, oxygen 21 percent, and other gases like carbon dioxide, argon, and others comprise 1 percent by volume.

The highest mountain peak Mt. Everest is 8,848 metres above the sea level.

Lithosphere provide us forests, grasslands for grazing land for agriculture and human settlements. It is a rich source of minerals.

 Emissions from industries, thermal power plants, and vehicles, pollute the air. Carbon dioxide (CO2 ) is an important constituent of air. But an increase in the amount of CO 2 leads to an increase in global temperatures. This is termed as global warming.

Water covers a very big area of the earths surface and this area is called the Hydrosphere. The Hydrosphere consists of water in all its forms. As running water in oceans and rivers and in lakes, ice in glaciers, underground water and the water vapour in atmosphere, all comprise the hydrosphere. Oceans are the major part of hydrosphere.

Humans are an important part of life on the earth, their activities affect other species' life profoundly. For example, cutting forests for fulfilling our needs of wood, or clearing land for agriculture may lead to the fast removal of soil from slopes. This has implications for vegetation and animal life which are dependent on this ecosystem. Similarly, the Discharge of waste material into lakes and rivers makes the water unsuitable for human use. It also damages other forms of life.

Antarctica, completely in the Southern Hemisphere, is a huge continent. The South Pole lies almost at the centre of this continent. As it is located in the South Polar Region, it is permanently covered with thick ice sheets. There are no permanent human settlements. Many countries have research stations in Antarctica. India also has research stations there. These are named as Maitri and Dakshin Gangotri.

Asia is the largest continent. It covers about one-third of the total land area of the earth. The continent lies in the Eastern Hemisphere. The Tropic of Cancer passes through this continent. Asia is separated from Europe by the Ural Mountains on the west. The combined landmass of Europe and Asia is called the Eurasia(Europe+Asia).

The four layers of the earths surface are lithosphere, Atmosphere, Hydrosphere and Biosphere.The solid portion of the earth on which we live is called the Lithosphere. The gaseous layers that surround the earth, is the Atmosphere, where oxygen, nitrogen, carbon dioxide and other gases are found. Water covers a very big area of the earths surface and this area is called the Hydrosphere. The Hydrosphere comprises water in all its forms, that is,ice, water and water vapour. The Biosphere is the narrow zone where we find land, water and air together, which contains all forms of life.

South America lies mostly in the Southern Hemisphere. The Andes, worlds longest mountain range, runs through its length from north to south. South America has the worlds largest river, the Amazon. Isthmus of Panama, a narrow strip of land linkedSouth America to North America.

The biosphere is the narrow zone of contact between land, water, and air. It is in this zone that life exists due to its favorable conditions for life survival. That is why the biosphere is also known as the Zone of Life.

Africa is the second largest continent after Asia. The Equator or 00 latitude runs almost through the middle of the continent. A large part of Africa lies in the Northern Hemisphere. Africa is the only continent through which the Tropic of Cancer, the Equator and the Tropic of Capricorn pass. The Sahara Desert, the worlds largest hot desert, is located in Africa. The continent is bound on all sides by oceans and seas. The worlds longest river the Nile, flows through Africa.

Australia is the smallest continent that lies entirely in the Southern Hemisphere. Itis surrounded on all sides by the oceans and seas. It is called an island continent.

The earth is surrounded by a layer of gas called the atmosphere. This thin blanket of air is an integral and important aspect of the planet. It provides us with the air we breathe and protects us from the harmful effects of suns rays. The atmosphere is divided into five layers which are the troposphere, the stratosphere, the mesosphere, the thermosphere and the exosphere. The atmosphere is composed mainly of nitrogen and oxygen, which make up about 99 per cent of clean, dry air. Nitrogen 78 percent, oxygen 21 per cent and other gases like carbon dioxide, argon and others comprise 1 per cent by volume.The density of the atmosphere varies with height. It is maximum at the sea level and decreases rapidly as we go up. The atmosphere exerts pressure on the earth. This varies from place to place. Some areas experience high pressure and some areas low pressure. Air moves from high pressure to low pressure.

The Indian Ocean is the only ocean named after a country, that is, India. The shape of ocean is almost triangular. In the north, it is bound by Asia, in the west by Africa and in the east by Australia. The Arctic Ocean is located within the Arctic Circle andsurrounds the North Pole. It is connected with the Pacific Ocean by a narrow stretch of shallow water known as Bering strait. It is bound by northern coasts of North America and Eurasia.

The biosphere is the narrow zone of contact between the land, water and air. All the living organisms including humans are linked to each other and to the biosphere for survival. The three domains of the earth interact with each other and affect each other in some way or the other. For example, cutting of forests for fulfilling our needs of wood, or clearing land for agriculture may lead to fast removal of soil from slopes. Similarly earths surface may be changed due to natural calamities like earthquakes. Discharge of waste material into lakes and rivers makes the water unsuitable for human use. It also damages other forms of life. Emission from industries, thermal power plants and vehicles, pollute the air. Carbon dioxide (CO2) is an important constituent of air. But increase in the amount of CO2 leads to increase in global temperatures. This is termed as global warming. There is thus, a need to limit the use of resources of the earth to maintain the balance of nature between the domains of the lithosphere, the atmosphere and the hydrosphere. That is why Biosphere is important for living organisms.

The Pacific Ocean is the largest ocean. It is spread over one-third of the earth.Mariana Trench, the deepest part of the earth, lies in the Pacific Ocean. The Pacific Ocean is almost circular in shape. Asia, Australia, North and South Americas surround it. Look at the map and find out the location of the continents around the Pacific Ocean.

The Atlantic Ocean is the second largest Ocean in the world. It is S shaped. It is flanked by the North and South Americas on the western side, and Europe and Africa on the eastern side. The coastline of Atlantic Ocean is highly indented. This irregular and indented coastline provides ideal location for natural harbours and ports. From the point of view of commerce, it is the busiest Ocean.

 Lithosphere is the outermost layer of Earth consisting of crust and upper mantle portion of the earth. 

The Biosphere is the narrow zone where we find land, water and air together, which contains all forms of life.

Lithosphere is the solid crust or the hard top layer of the earth. It is made up of rocks and minerals. It is covered by a thin layer of soil. It is an irregular surface with various landforms such as mountains, plateaus, desert, plains, valleys, etc. Lithosphere plays an important role in our life. It provides us forests, grassland for grazing, land for agriculture and human settlements. It is also a treasure of various minerals.