Chapter 1 – Environment
NCERT Solutions
Q.1.(i) What is an ecosystem?
Ans: An Ecosystem is constituted by relations of interdependence of plants, animals and human beings with one another and their dependence on immediate surroundings.
Alternatively, an Ecosystem is the system formed as a result of the interactions of all living organisms with each other, and with the physical and chemical factors of the environment in which they live.
Q.1.(ii) What do you mean by natural environment?
Ans: The environment that consists of all objects created by nature is called natural environment. The natural environment comprises land, water, air, plants and animals.
Q.1.(iii) Which are the major components of environment?
Ans: The major components of 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).
Q.1.(iv) Give four examples of human-made environment.
Ans: Examples of human-made environment:
Zoo
Rail tracks
Factories
Buildings
Q.1.(v) What is lithosphere?
Ans: Lithosphere (or the domain of land) 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 landforms such as mountains, plateaus, plains and valleys.
Q.1.(vi) Which are the two major components of biotic environment?
Ans: The two major components of biotic environment are:
(i) Plants
(ii) Animals
Q.1.(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.(i) Which is not a natural ecosystem?
(a) Desert (b) Aquarium (c) Forest
Ans: Aquarium
Q.2.(ii) Which is not a component of human environment?
(a) Land (b) Religion (c) Community
Ans: Land
Q.2.(iii) Which is a human-made environment?
(a) Mountain (b) Sea (c) Road
Ans: Road
Q.2.(iv) Which is a threat to environment?
(a) Growing plant (b) Growing population (c) Growing crops
Ans: 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 |
Ans:
|
(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 |
Q.4. Give reasons.
(i) Man modifies his environment
(ii) Plants and animals depend on each other
Ans:
(i) Man modifies his environment to fulfil his basic and ambitious needs, and also to adapt to the changing environment.
Man modifies his environment by:
Cutting forests and clearing the land for agriculture, industries, and habitation.
Tilling the land for agriculture.
Setting up buildings, roads and railways.
Using water.
Using air for his survival.
Setting up industries and factories.
(ii) Plants and animals are part of ecological system and depend on each other in the following ways:
Plants provide food to animals.
During photosynthesis, plants produce oxygen, which is necessary for the survival of all other living organisms.
Forests provide shelter to wildlife.
Forests are used by humans for various purposes like building houses, boats, furniture, etc.
Animals provide manure to plants for growth.
Animals help plants reproduce by helping in the pollination of seeds.
Carbon dioxide, used by plants for photosynthesis, is provided by humans and animals.
Dead animals provide humus to the soil.
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