- Books Name
- Social Science Book
- Publication
- Cognizance Publication
- Course
- CBSE Class 7
- Subject
- Social Science
Chapter 1
Environment
Environment is our basic life support system. It provides the air we breathe, the water we drink, the food we eat and the land we live. It is originated from French word Environer/Environner meaning “neighbourhood”. Anything that surrounds any living organism is called environment.It is a combination of natural and human made phenomena.Thenatural environment refers to both biotic and abiotic conditions existing on the Earth.Human environment reveals the activities, creations and interactions among human beings.
Biotic-The world of living organisms, example- plants and animals.
Abiotic-The world of non living animals example land.
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
Land, water, air, plants and animals comprise the natural environment.Anything surrounds any living organism which was not made by humans is a part of Natural Environment.Natural environment is classified into various domains:
[1] Lithosphere
[2] Hydrosphere
[3] Atmosphere
[4] 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.Landforms are found over the continents and also on the ocean floors.This domain provides us forests, grassland for grazing, land for agriculture and human settlement.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. The gravitational force of the earth holds the atmosphere around it. It protects us from the harmful rays and scorching heat of the sun.It consists of number of gases, dust and water vapour.The changes in the atmosphere produces changes in the weather and climate.
Biosphere
The plants 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 depends on each other and their immediate surroundings form an ecosystem. There could be ecosystem of large rainforest, 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 needs.Early humans adapted themselves to the natural surroundings. They led a simple life and fulfill their requirement from the nature around them.With time, needs grow and become more varied.Humans learn new ways to use and change environment.They learn to grow crops, domesticated 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 make communication easier and speedy across the world.
Barter system- It is the trade in which goods are exchanged without the use of money. On 5th June every year, the World Environment Day is celebrated.