These DAV Class 7 SST Notes and DAV Class 7 SST Chapter 1 Notes – Components of Environment hold significant importance as study material for students.
Components of Environment Class 7 DAV Notes
→ Environment is our basic support system. It provides us air, water, food and land. It also includes plants, animals and a great variety of man-made things. Thus, environment has both natural and man-made elements.
→ The natural environment can be classified into two groups- the physical environment and the biological environment.
→ The physical environment includes the non-living elements of the environment such as, the land, water and air. The biological or biotic environment includes all living things; such as, plants, animals and other living organisms. These two types of environment interact with each another.
→ The natural environment can be divided into four broad spheres- lithosphere, atmosphere, hydrosphere and biosphere.
→ The literal meaning of ‘lithosphere’ is the ‘sphere of rocks’. The literal meaning of ‘atmosphere’ is the ‘sphere of air’. Hydrosphere refers to the ‘sphere of water’ which is present in oceans, rivers, lakes and other water bodies on the earth’s surface. The word ‘biosphere’ literally means the ‘sphere of life’.
→ Earth is full of diversities. There is diversity in land, soil, plants and animals. To protect and conserve them, the Government of India has passed the Wildlife Protection Act 1972, under which now 103 National Parks and 535 Wildlife Sanctuaries have been established in different parts of India.
→ Environment: Surroundings or the conditions under which plants, animals and a large variety of man-made things exist and develop themselves.
→ Physical environment: It includes all non-living things like land, water and air.
→ Biological environment: It includes all living things, such as, plants and animals.
→ Lithosphere : It refers to the solid portion of the earth where we live.
→ Atmosphere : It refers to the gaseous envelope that surrounds earth.
→ Hydrosphere : It refers to the waterbodies that exist on earth’s surface.
→ Biosphere : It is the narrow zone where we find land, water and air together. Life exists in this zone.
→ Biodiversity : It is a variety of life on the earth comprising of plants, animals and micro-organisms.
→ Microbes : Very small organisms.
→ Ocean : Vast expense of saline water on the earth’s surface.
→ National Park : A well demarcated reserved area for the protection of wildlife, which does not allow any human activity.
→ Wildlife Sanctuary : A geographical area meant for the conservation of biodiversity. Limited human activities are permitted.