Q1. Answer the following questions.

(i) What is an ecosystem?


  • Plants, animals and human beings depend on their immediate surroundings.
  • The interactions of all living organisms  with the physical and chemical factors of the environment
  •  These relations of dependence and interdependence together known as an ecosystem.

(ii) What do you mean by natural environment?


  • The environment that consists of all objects created by nature is called natural environment.
  • The natural environment comprises land, water, air, plants and animals.

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

ANS- The major components of the environment are-

  • Natural environment (consists of all objects created by nature).
  • Human environment (consists of human beings).
  • Human-made environment (consists of objects created by human beings).

(iv) Give four examples of human made environment.

ANS-  Parks, buildings, roads and industries.

(v) What is lithosphere?


  • Lithosphere is the solid crust or the hard top layer of the earth.
  • It is made up of rocks and minerals, and is covered by a thin layer of soil.
  • It is an irregular surface with various land forms such as mountains, plateaus, plains and valleys.

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

ANS- Plants and animals.

(vii) What is biosphere?

ANS- Biosphere is the narrow zone of the Earth where land, water and air interact with each other to support life.

Q 2. Tick the correct answer.

(i) Which is not a natural ecosystem?

(a) Desert                                    (b) Aquarium                          (c) Forest

ANS-  (b) Aquarium

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

(a) Land                                        (b) Religion                             (c) Community

ANS- (a) Land

(iii) Which is a human made environment?

(a) Mountain                                (b) Sea                                       (c) Road

ANS- (c) Road

(iv)  Which is a threat to environment?

(a) Growing plant                       (b) Growing population          (c) Growing crops

ANS- (b) Growing population

Q 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


(i) Biosphere                                            (e) narrow zone where land, water and air interact.

(ii) Atmosphere                                       (a) blanket of air which surrounds the earth

(iii) Hydrosphere                                     (b) domain of water

(iv) Environment                                     (d) our surroundings

Q4. Give reasons.

(i) Man modifies his environment.


  • The environment is our basic life support system.
  • To fulfill his needs, man builds homes and factories and modifies the environment .
  •  For food, shelter and agriculture, he cuts forests and utilizes water.
  • Due to industrial revolution and technological advancement, man has used fossil fuels such as coal and petroleum.

(ii) Plants and animals depend on each other.


  • Plants and animals are interdependent. Plants consume carbon dioxide and give oxygen to air and prepare food, thus are producers.
  •  Animals consume plants and plant products. They also absorb oxygen and release carbon dioxide for plants.