NCERT Summary: Environment - Notes | Study Social Studies (SST) Class 7 - Class 7

Environment

• Environment originated from French word Environer/Environner meaning “neighbourhood”.
• Anything that surrounds any living organism is called environment.
• Components of Environment:
  • Natural: Air (Atmosphere), Water (Hydrosphere), Land (Lithosphere), Living things (Biosphere).
  • Human interactions:  Individual, Family, Society, Religion, Education, Political Situation, Economic.
  • Human made: Parks, Buildings, Bridges, Roads, Industries, Monuments.

Natural Environment

Anything surrounds any living organism which was not made by humans is a part of Natural Environment.

• Both biotic (living organisms) and abiotic (non-living organisms) are included in natural environment.
• The natural environment is classified into various domains:
  • Lithosphere
  • Hydrosphere
  • Atmosphere
  • Biosphere

Lithosphere

• It is the solid crust or the hard top layer of the earth.
• It is made up of rocks and minerals and covered by a thin layer of soil.
• It is an irregular surface with various landforms such as mountains, plateaus, plains, valleys, etc.
• This domain provides us forests, grasslands for grazing, land for agriculture and human settlements.
• It is also a source of mineral wealth.

Hydrosphere

• Hydrosphere is the domain of water.
• It comprises various sources of water and different types of water bodies like rivers, lakes, seas, oceans, etc.
• It is essential for all living organisms.

Atmosphere

• The atmosphere is the thin layer of air that surrounds the earth.
• It consists of a number of gases, dust and water vapour.
  • The changes in the atmosphere produce changes in the weather and climate.
• The gravitational force of the earth holds the atmosphere around it.
• It protects us from the harmful rays and scorching heat of the sun.

Biosphere

• The living world is called Biosphere.
  • The plant and animal kingdom together make biosphere.
• It is a narrow zone of the earth where land, water and air interact with each other to support life.

Ecosystem

• It is a system formed by the interaction of all living organisms with each other and with the physical and chemical factors of the environment in which they live, all linked by transfer of energy and material.
• All plants, animals and human beings depend on each other and their immediate surroundings form an ecosystem..
• There could be an ecosystem of large rain forest, grassland, desert, mountains, lake, river, ocean and even a small pond.

Human Environment

• Human beings interact with the environment and modify it according to their need.
• With time human needs grew and became more varied.
• Humans learn new ways to use and change environment.
  • They learn to grow crops, domesticate animals and lead a settled life.
  • The wheel was invented, surplus food was produced, barter system emerged, trade started and commerce developed.
  • Industrial revolution enabled large scale production.
  • Transportation became faster.
  • Information revolution made communication easier and speedy across the world.