NCERT 7th Class (CBSE) Social Science: Our Environment

Question: Give an account of various domains of the environment.

Answer: Various domains of the environment are:

1. Lithosphere
2. Atmosphere
3. Hydrosphere
4. Biosphere
5. 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 provides us forests, grasslands and land. It is a source of mineral wealth.
6. It 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 harmful rays and scorching heat of the sun. It consists of various gases, dust and water vapour.
7. It refers to various water bodies such as rivers, lakes, seas, oceans, etc. that exist on the earth.
   Biosphere or the living world is comprised of plant and animal kingdom. It is a narrow zone of the earth where land, water and air interact with each other to support life.

Question: How have human beings adapted to the environment to fulfill their needs?

Answer: Human beings from the early times have been interacting with the environment and modifying it according to their needs. Early humans adapted themselves to the natural surroundings. They led a simple life and fulfilled their requirements from the nature around them. But their needs kept on increasing. They became varied also. To fulfill these varied needs, humans learnt to grow crops, tamed animals and began a settled life. The wheel was invented, surplus food was produced, barter system emerged, trade started and commerce developed. Industrial revolution made possible large scale production. By and by transportation became faster. Information revolution made communication easier and speedy across the world. In this way human beings adapted to the environment in order to fulfill their needs.

Question: Define environment. How can you classify the environment?

Answer: The environment is the sum of all the conditions that surround and influence a human beings at any given point of time and space. Environment consist of the natural environment and the human-made environment.

Question: Distinguish between Physical and Biological environment.

Answer: Difference is as follows:

Question: How do human adapt themselves to the environment. Give examples.

Answer: They adapt themselves to natural environment by making modifications in their shelter, food and clothing. They also modify the natural environment to suit their social, biological, economic and cultural needs. For example – People who live in hot, wet coastal areas like Kerala or Coastal Odisha traditionally eat rice and fish. They also wear cotton clothes which keep them cool and live in houses with sloping roofs so that rain can run off easily.

Question: List some environmental issues.

Answer: Some issues are:

1. Over-population.
2. Pollution – air, water, land and noise pollution.
3. Deforestation
4. Poaching