Major Domains of the Earth – Class 6 Geography Notes

Class 6 Geography – Chapter: Major Domains of the Earth
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Chapter Overview: This chapter explores the four major components that make our Earth a living planet — the Lithosphere, Atmosphere, Hydrosphere, and Biosphere. Designed for Class 6 CBSE/NCERT students, these simplified notes are perfect for exam preparation and conceptual clarity.

🌍 What are the Major Domains of the Earth?

The Earth is a unique planet because it supports life. This is possible due to the interaction of four major domains:

  • Lithosphere – The solid, outer part of the Earth.
  • Hydrosphere – All water bodies on Earth.
  • Atmosphere – The layer of gases around Earth.
  • Biosphere – The zone where life exists (interaction of the other three).
📝 Exam Tip: A common one-mark question is: "Name the domain where all forms of life exist." The answer is Biosphere.

🗺️ 1. Lithosphere – The Solid Surface

The Lithosphere is the rigid outer part of the Earth, consisting of rocks and soil. It includes continents and ocean basins.

  • Earth has 7 continents: Asia, Africa, North America, South America, Antarctica, Europe, and Australia.
  • Asia is the largest continent and is joined with Europe to form Eurasia.
🧠 Remember: Asia > Africa > North America in size ranking of continents.

🌊 2. Hydrosphere – Water on Earth

The Hydrosphere comprises all water bodies — oceans, seas, rivers, lakes, underground water, and water vapor.

  • About 71% of Earth is covered by water, but only 3% is freshwater.
  • The five oceans (in size order): Pacific, Atlantic, Indian, Southern, and Arctic.
📌 Important: The Pacific Ocean is the largest and deepest ocean.

☁️ 3. Atmosphere – Blanket of Air

The atmosphere is a layer of gases surrounding the Earth and is essential for life. It provides oxygen, carbon dioxide, and protects us from harmful sun rays.

  • It extends up to 1,600 km above Earth’s surface.
  • Main gases: Nitrogen (78%), Oxygen (21%), others like CO₂, Argon (1%).
🌬️ Exam Insight: Nitrogen is the most abundant gas, and Oxygen is essential for breathing.

🌱 4. Biosphere – Life on Earth

The Biosphere is the zone where land, water, and air interact to support life. It includes humans, animals, plants, and microorganisms.

This is the most dynamic and delicate domain, depending on the balance between all three others.

💡 Smart Point: Damage to any one domain (like air pollution in the atmosphere) can disturb the Biosphere.

📘 Summary Table – Major Domains

Domain Description Key Component
Lithosphere Solid part of Earth Continents & mountains
Hydrosphere All water bodies Oceans, rivers, lakes
Atmosphere Layer of gases O₂, N₂, CO₂
Biosphere Life-supporting zone Plants, animals, humans

🧾 Learning Outcomes

  • Understand the concept of Earth's domains
  • Differentiate between continents and oceans
  • Know the composition of the atmosphere
  • Realize the importance of a balanced biosphere

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Designed for CBSE/NCERT Class 6 – Best for School Exams, Olympiads & Competitive Foundations