CBSE Class 6 Social Science Geography Revision Notes Chapter 5

Class 6 Geography Chapter 5 Notes

CBSE Class 6 Geography Chapter 5 Notes – Major Domains Of The Earth

The Earth is the only planet where life exists. The major components play a crucial role in making a suitable environment where life can flourish. Class 6 Geography Chapter 5 Notes imparts in-depth knowledge of the four major domains of the Earth. Students will learn important terms like lithosphere, hydrosphere, atmosphere, biosphere, etc. These notes have been carefully prepared by the subject matter experts in concise points. Students can refer to these notes to gain conceptual clarity of the topics and answer all the questions in the exam hall.

These notes cover all the important points of the entire chapter. Subject matter experts have consulted the updated CBSE Syllabus and guidelines while making these notes. Students can therefore easily access up-to-date, high-quality study materials without having to worry about their authenticity. These notes will help students solve all doubts related to the chapter. They will be able to revise the entire chapter in a short and precise manner.

Major Domains Of The Earth Class 6 Geography Chapter 5 Notes

Access Class 6 Social Science Chapter 5 – Major Domains Of The Earth Notes

Short Details about The Major Domains of The Earth

The Earth has four major domains. The solid component, or Lithosphere; the liquid component, or Hydrosphere; the gaseous part, or Atmosphere; and the component where all three components meet, overlap and interact, known as the Biosphere. All of them are essential for sustaining life on Earth.

  • Lithosphere: As mentioned earlier, the lithosphere forms the solid part of the Earth’s surface. It consists of hard rocks and thin layers of soil enriched with minerals and nutrients that are used by green plants to prepare food. The lithosphere is the area where life exists. It has many landforms like plateaus, mountains, valleys, etc. Mount Everest is its highest point, with a height of 8,848 metres.
  • Atmosphere: The Earth’s atmosphere comprises many gases. Nitrogen, oxygen, carbon dioxide, etc., are some of the important gases present in the atmosphere. Oxygen is called the life-supporting gas as it is crucial for breathing. It protects the Earth like a shield from the UV rays and incredible heat of the Sun. Troposphere, stratosphere, mesosphere, thermosphere, and exosphere are its sub-layers.
  • Hydrosphere: Oceans, seas, rivers, ponds, and other water bodies are together called the hydrosphere. Three-fourths of the Earth is covered by the hydrosphere, due to which the Earth looks blue from space. Hence, it is known as the “Blue Planet. Water exists in the hydrosphere in three states: liquid in water bodies, solid in polar regions as ice, and vapour in the atmosphere.
  • Biosphere: It is a narrow zone in the environment where land, water, and air are found together, making it suitable for living beings. Plants, animals, and various microbes co-exist in this place. No other planet has the conditions for making a biosphere except the Earth. Changes in any one of the domains impact the other domains as well.

Lithosphere

The solid section of Earth that is made up of rocks and soil is known as the lithosphere. The soil contains all the nutrients necessary for sustaining life on the Earth’s crust. The Earth’s crust is also divided into two parts. One-third of it is further divided into seven continents, and two-thirds of it is covered by vast oceans. The continents are separated by the interconnected oceans. Asia, Africa, Europe, North America, South America, Australia, and Antarctica are the seven continents in the world.

Asia is the largest continent in the world. The Ural Mountain separates it from Europe. The Tropic of Cancer passes through it. Africa is the second largest continent and the only continent where the Tropic of Cancer, the Equator, and the Tropic of Capricorn pass through altogether. Europe is the third largest continent and is traversed by the Arctic Circle. North America and South America are the other two important continents connected by the Isthmus of Panama. Antarctica is in the polar region of the Southern Hemisphere. It is not suitable for human settlement because of its wintry atmosphere. Australia is the smallest continent. It is also known as the island continent.

The height of the lithosphere is not uniform. Height is calculated with respect to the sea level, which is assumed to be zero. Mount Everest is measured to be 8,848 km above sea-level and is said to be the highest point of the lithosphere.

Hydrosphere

71% of the entire planet is occupied by the hydrosphere. It consists of water in all forms. Water in liquid form flows in rivers and oceans, and it is also stored in tanks, ponds, and beneath the ground as subsurface water. The glaciers and Arctic regions also contain water in frozen form. Water is also present in the atmosphere in the form of vapour. Though the major part of the Earth is covered by water, most of it is unusable due to salinity. The Pacific Ocean, Atlantic Ocean, Indian Ocean, Southern Ocean, and Arctic Ocean are the five major oceans in the world. Among them, the Pacific Ocean is the largest, covering one-third of the Earth’s surface.

Atmosphere

Atmosphere is the layer of gaseous elements that surrounds the Earth like a blanket. The function of the atmosphere is to protect the Earth from the harmful rays and extreme heat of the Sun. Further, the atmosphere contains oxygen, the life-supporting gas which is crucial for both the plant kingdom and the animal kingdom.

This atmosphere extends up to a height of 1600 km above the earth’s surface and is divided into five sub-layers. Troposphere, stratosphere, mesosphere, thermosphere, and exosphere are the layers.This classification is done on the basis of their composition, temperature, and other properties.

The two main constituent gases of the atmosphere are nitrogen and oxygen. They are present in 78% and 21%, respectively. The remaining 1% comprises carbon dioxide and other gases. There is no substitute for nitrogen in the growth of plants and other living organisms. Oxygen is required for respiration, and carbon dioxide helps absorb the heat radiated by the Earth thus keeping the planet warm.

Biosphere

Biosphere is the domain of Earth where all the other three domains, viz. Atmosphere, Lithosphere, and Hydrosphere, collide. Land, water, and air, which are essential for life, are found in this domain. Hence, the biosphere has become the home for all living creatures. Different types of microbes, bacteria, plants, insects, animals, and fish exist in this region. The interactions that take place among them deeply influence the environment.

FAQs (Frequently Asked Questions)

There are four major domains of the Earth. They are as follows:

  1. Lithosphere: It is the upper surface of the Earth, which forms continents. It is made of hard rocks and thin layers of soil.
  2. Atmosphere: It is the layer formed by gaseous elements that surround the Earth like a blanket. It contains important gases like nitrogen, oxygen, and carbon dioxide which contribute to the existence of life in various ways.
  3. Hydrosphere: Water exists in this domain. The hydrosphere covers two-thirds of the earth.Most of the water is in the oceans, which cannot be used for day-to-day activities.
  4. Biosphere: The biosphere is the domain in which the other three domains interact and provide a home for all living things.

Earth is the only planet where water is present in liquid form in  abundant quantities. The vast oceans appear blue from space. As a result, Earth is known as the Blue Planet.. However, the saline water of the vast oceans cannot be used in daily life. Further, the little amount of usable water that is present is also frozen in the glaciers and polar regions. Therefore, the amount of usable fresh water is very limited. Hence, there is a scarcity of usable water on Earth.

There are seven major continents in the world. They are Asia, Africa, Europe, North and South America, Australia, and Antarctica.

  1. Asia: It is the largest continent in the world, lying in the Eastern hemisphere. The Tropic of Cancer passes through it. The Ural Mountains separate it from the European continent. The combined landmass of Europe and Asia is known as Eurasia.
  2. Africa: It is the second largest continent. The Tropic of Cancer, the Tropic of Capricorn, and the Equator all pass through the continent. The longest river in the world, Nile, flows through this continent. The Sahara Desert, which is the largest and hottest place in the world, is also located here.
  3. Europe: The three sides of this continent are surrounded by water, and one side is connected to Asia. The Arctic Circle traverses this continent.
  4. North America: This continent is located in the Western and Northern hemispheres. It is connected to South America by a narrow stretch of land known as the Isthmus of Panama.
  5. South America: The world’s longest mountain range, the Andes, is located on this continent. Besides, the world’s largest river, the Amazon, flows through it.
  6. Antarctica: It is located in the polar region of the Southern hemisphere. Its icy atmosphere is not suitable for human settlement. This continent is generally used for research activities. The two Indian research centres located here are Maitri and Dakshini Gangotri.Australia: It is the smallest continent and is bordered by water on all sides. Therefore, it is also known as the island continent.

The CBSE Syllabus introduces students to the concept of domains of the Earth in Class 6. It is the fifth chapter in the NCERT Geography book. The chapter discusses not only the domains individually but also how they collide and interact with one another, and the importance of these interactions. The revision notes provided by Extramarks are well-organised and comprehensive. Students can refer to these notes to better understand the concepts and fetch more marks in the exam.

The Pacific Ocean is the largest ocean in the world. About one-third of the world is occupied by it. The deepest point of the lithosphere, the Mariana Trench, is also in this ocean. It surrounds the four major continents of the world, namely, North America, South America, Asia, and Australia.

The Atlantic Ocean is the second largest ocean, which resembles the letter “S”. Europe and Africa lie on its Eastern part, and North and South America are  on its Western part. The irregular and indented coastlines of the aforementioned continents make the Atlantic the busiest ocean from the perspective of commercial activities.

The biosphere is the home of all living organisms. It provides a place to live, food to sustain life, and fresh air to breathe. It is the only place on  Earth that is suitable for living. Species of all kinds, starting from microscopic bacteria to huge animals like elephants, can be found here.

The atmosphere contains oxygen, which is essential for breathing. Nitrogen, which constitutes the major part of the atmosphere, is also crucial for the growth and development of plants and animals. Carbon dioxide is another important gas, though it is present in a small amount. There are other gases that directly or indirectly influence the biosphere. Besides, the atmosphere protects the Earth from the harmful cosmic rays and excessive heat of the sun.

The different layers of the atmosphere are the troposphere, stratosphere, mesosphere, thermosphere, and exosphere. Such divisions are made depending on the constituent elements and temperatures of the various levels of the atmosphere.