NCERT Solutions For Class 7 Geography Social Science Chapter 1 Environment
Question 1.
Answer the following questions briefly.
i. What is an ecosystem?
ii. What do you mean by the natural environment?
iii. Which are the major components of the environment?
iv. Give four examples of a human-made environment.
V. What is the lithosphere?
Vi. Which are the two major components of the biotic environment?
Vii. What is the biosphere?
Answer:
i. All plants, animals and human beings depend on their immediate surroundings. They are also interdependent on each other. This relation between the living organisms as well as the relation between the organism and their surroundings form an ecosystem.
ii. The natural environment consists of land, water, air, plants and animals. Thus, the natural environment refers to both biotic (plants and animals) and abiotic (land) conditions that exist on the earth.
iii. The major components of the environment are—natural (land, air, water, living things), human-made (buildings, parks, bridges, roads, industries, monuments, etc.), and humans (individual, family, community, religion, educational, economic, etc).
iv. Four examples of human-made environments—buildings, parks, bridges, and roads.
V. The 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.
Vi. Plants and animals are the two major components of a biotic environment,
Vii. The biosphere is a narrow zone of the earth where land, water, and air interact with each other to support life. Thus, plant and animal kingdom together make biosphere, ie., the living world.
Question 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 the 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 the environment?
(a) Growing plant (b) Growing population
(c) Growing crops.
Answer:
(i)—(b), (ii)—(a), (iii)—(c), (iv)—(b).
Question 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) the narrow zone where land, water, and air interact
Answer:
i. (e)
ii. (a)
iii. (b)
iv. (d)
Question 4.
Give reasons:
A. Man modifies his environment
B. Plants and animals depend on each other.
Answer:
A. Man modifies his environment in the following ways:
•He cuts forests and clears land for agriculture, industries, and habitation.
•He tills land for agriculture.
•He uses the land to build buildings, roads, and railways.
•He uses water.
•He uses air for his survival.
•He sets up industries, factories, etc.
•He does numerous other activities for his life, making it comfortable.
B. Plants and animals depend on each other in the following ways:
•Plants provide food to animals.
•They, in the form of forests, provide shelter to wildlife.
•Wildlife adds beauty to the forests.
•Animals provide manure to plants for growth.
•Animals also provide beauty to forests.
•Dead animals also provide humus content.
