→ The place, people, things and nature that surround any living organism is called environment.

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.

→ Environment: French word Environner/ Environner meaning “Neighbourhood”.

→ The domain of water is referred to as hydrosphere.

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

→ 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.

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

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