Answer: (b) Environment

Answer: (b) Mountains, rivers and trees

Answer: (a) hydrosphere

Answer: (a) Biosphere

Answer: (a) Camel

Answer: (d) 5th June

Answer: (a) Human beings

Answer: (b) Growing plants

Answer:

Answer: biosphere

Answer: natural, man-made

Answer: Lithosphere

Answer: Human beings

Answer: False

Answer: True

Answer: True

Answer: False

Answer: False

Question 1.
What made Ravi sad while going to school after vacation?
Answer:
After the long vacation while going to school Ravi noticed that the only play-ground next to the school is dug up. He was told that a multi storey building would be constructed there.

This made him sad as the big playground with grass, marigolds and butterflies would be gone forever. He shared his feelings with his classmates.

Question 2.
What all are the part of our environment?
Answer:
Our Surroundings constitute environment. Buildings furniture like tables, chairs, open field, road, garbage etc. are all part of our environment. Some things like mountains, rivers, trees are created by nature. Others like chair, table, roads and clothes are made by man.

Question 3.
Why is our environment changing?
Answer:

• It is all because of our needs.
• They are increasing day by day.
• We are therefore modifying and at times even destroying our natural surroundings.

Question 4.
How do human beings modify the environment?
Answer:
Environment provides the basic life support system like air, water, food and land. The man made things like car pollute the air, factories build on land, containers for food and water are the examples of modification of environment.

Question 5.
Distinguish between biotic and abiotic environments.
Answer:
Biotic Environment

• The world of living organisms is called biotic environment.
• Examples: Plants and animals.
  Abiotic Environment
• The world of non-living elements is called abiotic environment.
• Example: Land.

Question 6.
Explain with examples the different components of environment.
Answer:
Major Components of environment are – Man-made, natural and Human beings.
Major Components of the Environment:
Natural Components:

• Land (Lithosphere).
• Water (Hydrosphere).
• Air (Atmosphere).
• Living things (Organisms).

Human-made Components:

• Buildings.
• Parks.
• Bridges.
• Roads.
• Monuments.
• Industries.

Humans

• Individuals
• Family
• Community
• Religion
• Education
• Economic
• Political situation

Examples of Human-made Environment:

• Buildings
• Parks
• Bridges
• Roads
• Monuments
• Industries

Question 7.
What is environment?
Answer:
The surrounding in which we live forms environment. It is the basic life support system having natural and man-made components.

• The people, the place, the things, the nature and the living organisms that surround us are called environment.
• It is a combination of natural and human made phenomena.
• The natural environment refers to both biotic and abiotic conditions existing on the earth.
• Human environment reveals the activities, creations and interactions among human beings.

Natural Environment

Question 1.
What comprises natural environment?
Answer:
Land, air, water, plants and animals are all the part of natural environment.

Question 2.
Describe lithosphere and hydrosphere.
Answer:
Lithosphere

• It is the solid crust or the hard top layer of the earth.
• It is made up of rocks and minerals.
• It is covered by a thin layer of soil.
• It is an irregular surface with various landforms like mountains, plateaus, plains, valleys etc.
• Landforms spread over the continents and also on the ocean floors.

Lithosphere provides us the following:

• Forests.
• Grasslands for grazing.

• Land for agriculture and
• Human settlements.
• It is also a source of mineral wealth.

Hydrosphere is the domain of water.

• It comprises various sources of water.
• The different types of water bodies like rivers, lakes, seas, oceans, etc. are its major components.
  • It is essential for all living organisms.

Question 3.
Give an account of the atmosphere.
Answer:

• The atmosphere is the thin layer of air that surrounds the earth.
• The gravitational force of the earth holds the atmosphere around it.
• It protects us from the harmful rays and scorching heat of the sun.
• It consists of numerous gases, dust and water vapour.
• The changes in the atmosphere produce changes in the weather and climate.

Question 4.
Define the term ‘Biosphere’.
Answer:
Biosphere: Plants and animals found in the narrow strip at the junction of lithosphere, atmosphere and hydrosphere together make biosphere.

What is Ecosystem?

Question 1.
What do you understand by the term “Ecosystem”?
Answer:
Ecosystem: An ecosystem is formed by the interaction of all living organisms with one another and with the physical and chemical factors of the environment in which they live. All are linked by transfer of energy and material. They are interdependent.

Question 2.
Compare and contrast the climatic conditions of Kerala and Rajasthan.
Answer:
Kerala, a southern state of India gets ample rainfall. It has lush green vegetation and coconut plantations.
Rajasthan, on the other hand, gets very less rainfall. It has thorny bushes, kikar and babul as vegetation.

Question 3.
Name some animals found in deserts.
Answer:
Camels, snakes, lizards, insects are found in deserts.

Question 4.
Why do the animals and vegetation vary from place to place?
Answer:
Animals and vegetation vary from place to place because

• They are dependent on their immediate surroundings.
• They depend on the environmental conditions like climate, soil, water etc.
• All of them sire interdependent on each other.

Question 5.
What forms the ecosystem? Give some examples of ecosystems.
Answer:
The relationship between the living organisms and their surroundings form the ecosystem. Rain forest, grassland, deserts, mountains, lake, river, ocean and pond are some of the examples of ecosystems.

Question 6.
Do you think the park in which Ravi and his friends played formed an ecosystem?
Answer:
Yes.

Human Environment

Question 1.
Define barter system.
Answer:
Barter system is the exchange of goods without the use of money.

Question 2.
What has brought a change in interaction between humans and their surroundings?
Answer:
Human being modifies nature according to their need. Early humans adapted themselves to their natural surroundings. They led a simple life fulfilling their needs from nature.

With changes in needs new methods and technologies were invented. Settled life brought agriculture domestication of animals. Invention of wheel, surplus food led to development of trade and commerce. Barter system emerged.

Industrial revolution, changes in transportation increased production. Growth in communication system made life easier and speedy. Humans learned new ways to use and change the surroundings.

Question 3.
What is important for a harmonious life?
Answer:
Certain things are used in a certain way like watermelon in summer or roasted peanuts in winter. We need a balance between natural and human environment. Human beings must use their natural environment in a sustainable way to maintain the balance.