Chapter 1 - Environment

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. 

the place, people, things and nature that surround any living organism is called environment. It is a combination of natural and human made phenomena. While the natural environment refers to both biotic and abiotic conditions existing on the earth, human environment reveals the activities, creations and interactions among human beings. 

Word Origin - Environment: French word Environer/ Environner meaning “neighbourhood”. 

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. 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. Lithosphere is the domain that provides us forests, grasslands for grazing, land for agriculture and human settlements. It is also a source of mineral wealth.

The domain of water is referred to as hydrosphere. 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. 

The atmosphere is the thin layer of air that surrounds the earth. The gravitational force of the earth holds the atmosphere around it. 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. 

Plant and animal kingdom together make biosphere or the living world. 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. 

On 5 June every year the World Environment Day is celebrated. 

Barter System: It is a trade in which goods are exchanged without the use of money. 

All plants, animals and human beings depend on their immediate surroundings. Often they are also interdependent on each other. This relation between the living organisms, as well as the relation between the organisms and their surroundings form an ecosystem. There could be an ecosystem of large rain forest, grassland, desert, mountains, lake, river, ocean and even a small pond. 

1. Answer the following questions. 

(i) What is an ecosystem? 

(ii) What do you mean by natural environment? 

(iii) Which are the major components of the environment? 

(iv) Give four examples of human made environment. 

(v) What is lithosphere? 

(vi) Which are the two major components of biotic environment? 

(vii) What is biosphere? 

2. Tick the correct answer. 

(i) Which is not a natural ecosystem? 

(a) Desert 

(b) Aquarium 

(c) Forest 

(ii) Which is not a component of human environment? 

(a) Land 

(b) Religion 

(c) Community 

(iii) Which is a human made environment? 

(a) Mountain 

(b) Sea 

(c) Road 

(iv) Which is a threat to environment? 

(a) Growing plant 

(b) Growing population 

(c) Growing crops 

3. Match the following. 

(i) Biosphere (a) blanket of air which surrounds the earth (ii) Atmosphere (b) domain of water (iii) Hydrosphere (c) gravitational force of the earth (iv) Environment (d) our surroundings (e) narrow zone where land water and air interact (f) relation between the organisms and their surroundings.

4. Give reasons. 

(i) Man modifies his environment 

(ii) Plants and animals depend on each other 

5. Activity. Imagine an ideal environment where you would love to live. Draw the picture of your ideal environment