1. Answer the following questions.
(i) What is an ecosystem?
Ans. It is the relation between the living organisms, as well as the relation between the organisms and their surroundings form an ecosystem. All plants, animals and human beings depend on their immediate surroundings for survival. It is this relationship that gives birth to an ecosystem.
(ii) What do you mean by natural environment?
Ans. All those things which are naturally existing around us are together called natural environment.
(iii) Which are the major components of the environment?
Ans. Following are the major components of the environment:
- Natural components.
- Human made components,
- Activities and interactions of human beings.
(iv) Give four examples of human made environment.
Ans. Bridges, Parks, Road, Buildings, etc are examples of human-made environment.
(v) What is lithosphere?
Ans. Lithosphere is the hard top layer of the earth. It comprises of the crust and the upper mantle.
(vi) Which are the two major components of biotic environment?
Ans. Plants and animals are the two major components of biotic environment.
(vii) What is biosphere?
Ans. Biosphere is the narrow zone of the earth where land, water and air support life by interacting with each other. Plant and animal kingdom together make biosphere or the living world.
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.
narrow zone where land, water and air interact
blanket of air which surrounds the earth
domain of water
4. Give reasons.
(i) Man modifies his environment.
Ans. Man modifies his environment to meet his various needs. For example, he clears forests for obtaining land for agriculture and for making shelter. He extracts minerals from the earth for making various things. He makes dams for producing electricity. These are a few of the ways in which man modifies his environment
(ii) Plants and animals depend on each other.
Ans. Animals, whether carnivores or herbivores,ultimately depend on plants for their food. Also,plants provide fresh oxygen for animals to breath. Plants also keep the environment clean and provide shelter to a number of animals, on the other hand, animals provide carbon dioxide which plants use for making their food. Dead and decaying matter of animals provide nutrients to plants to help them grow.