CBSE Class 7 Geography Chapter 1 Notes Understanding The Lesson
1. Environment is our basic life support system. It provides the air we breath, the water we drink, the food we eat and the land where we live.
2. Human beings modify to the natural environment by several means.
3. The place, people, things and nature that surround any living organism is called environment. It is a combination of natural and human made phenomena.
4. The natural environment refers to both biotic and abiotic conditions existing on the earth while human environment reveals the activities, creations and interactions among human beings.
5. The word ‘biotic’ is referred to living organizations such as plants and animals while non-living elements are called ‘abiotic’.
6. Land, water, air, plants and animals comprise the natural environment.
7. Lithosphere 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.
8. Lithosphere is an irregular surface with various landforms such as mountains, plateaus, plains, valleys, etc.
9. Lithosphere is the domain that provides us forests, grasslands, agricultural land and human settlements. It is also a source of mineral wealth.
10. Hydrosphere is domain of water. It comprises various sources of water such as rivers, lakes, seas, oceans, etc. It is essential for all living organisms.
11. 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 a number of gases, dust and water vapour. The changes in the atmosphere produce changes in the weather and climate.
12. All plants, animals and human beings depend on their immediate surroundings and also interdependent on each other. Relation between the living organisms, as well as the relation between the organisms and their surroundings form an ecosystem.
13. Early men adapted themselves to the natural surroundings and led a simple life. All needs were fulfilled from the nature around them. But, presently human beings interact with the environment and modify it according to their needs.