Social Science SHORT ANSWER QUESTIONS(3 Mark)

• 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.

Plant and animals kingdom together make biosphere or the living world. It is a narrow zone of the earth where land, water and air interact with each other to support life. It is different from other three realms because it is the only realm where life exits in all forms. The existence of Biosphere makes earth a unique planet. The components of the Biosphere are independent to the components of the Abiotic world to create a unique system that sustains the environment. This relation between the living organisms, as well as the relation between the organisms and their surrounding is called ecosystem.

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.

S.No.	Column A		Column B
1.	Land	(c)	Abiotic
2.	Animals, plants	(d)	Biotic
3.	Mountain, plateau and plains	(a)	Lithosphere
4.	Gases, water vapour, dust	(b)	Atmosphere

Humans are the one of the major part of natural environment. We have not yet learnt to include polluting land, freshwater, river, seas, ocean etc. Deforestation also led to destruction of habitats of flora & fauna species. Increase desertification of land, altering natural moderate our activities in such a way to help the environment. Some of the major impact of human waterways which can increase the risk of flooding. Increased erosion of land as a result of mining or agricultural activities. Mining activity contribute to instability in the earth crust.

A perfect balance is necessary between the natural and human environment. This is because human survival is depended on the natural environment. If human beings exploit their natural environement beyond its capacity to replenish, t pollutes the air, water and land that degreades the quality of human life also. If the human activities are keeping a balance to maintain a healthier natural environmental, it produces great wealth in the form of many resources and a healthier population. A healthy environment is also much less likely to cause large problems.

Human beings from the early times have been interacting with the environment and modifying it according to their needs. Early humans adapted themselves to the natural surroundings. They led a simple life and fulfilled their requirements from the nature around them. But their needs kept on increasing. They became varied also. To fulfil these varied needs, humans learnt to grow crops, tamed animals and began a settled life. The wheel was invented, surplus food was produced, barter system emerged, trade started and commerce developed. Industrial revolution made possible large scale production. By and by transportation became faster. Information revolution made communication easier and speedy across the world. In this way human beings adapted to the environment in order to fulfil their needs.

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.

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.

Lithosphere 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 such as mountains, plateaus, desert, plains, valleys etc. Lithosphere plays an important role in our life. It provides us forests, grassland for grazing, land for agriculture and human settlements. It is also a treasure of various minerals.

• Biotic World: it the living world consisting of all plant animal life. Elements from this word grown, reproduce and respond to stimuli.
• Abiotic world: It is the world of non living natural world consisting of land, water and air, Elements of this world do not grown or reproduce on their own but are depended on external forces for changing their form.

Plants and animal co exist in the environment with the transfer of energy and material mutually. They are interdependent on their biotic as well as abiotic surroundings.
Exchanges of gases: plants release oxygen and intake carbon dioxide released by the animal kingdom.
Food chain: the plants are being consumed by the herbivores animals and carnivores feed on the other animals. The dead remains of both plants and animals enrich the soil.

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.

1. Plants, animals and human beings depend on their immediate surroundings. They are interdependent.
2. This relation between the living organisms as well as the relation between the organisms and their surroundings form an ecosystem.
3. There could be an ecosystem of large rainforests, grasslands, desert, mountains, lake, rivers, etc.

Human beings interact with the environment and modify it according to their need. Early humans led a simple life and were dependent on nature. With time, humans learnt to grow crops, domesticate animals and lead a settled life. The wheel was invented, surplus food was produced, barter system emerged, trade started and commerce developed. Industrial revolution enabled largescale production. Transportation made movement faster and information revolution made communication faster. Humans, thus, learnt to interact with nature in a harmonious way.

• 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.

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.

The major components of the environment are-natural (land, air, water, living things), human made (buildings, parks, bridges, roads, industries, monuments, etc.) and human (individual, family, community, religion, educational, economic, etc).

The relation between the living organism, as well as the relation between the organisms and their surrounding forms an ecosystem. It is a system formed by the by the interaction of all organisms with each other and with the physical and chemical factors of the environmental in which they live, all linked by transfer of energy and material.

No, plants cannot take nitrogen directly from the air. Bacteria, that live in the soil and roots of some plants take nitrogen from the air and change it into the nitrogen compound form. This nitrogen compound is used by plants.

Biotic environment is the world of living organisms while abiotic environment is the world of non-living beings. Plants and animals are a part of the biotic environment, while land is a part of the abiotic environment.

1. Lithosphere is the solid crust or the hard top layer of the earth.
2. It is made up of rocks and minerals and covered by a thin layer of soil.
3. Lithosphere is the domain that provides us forests, grasslands for grazing, land for cultivation and human settlements.
4. It even provides us various minerals.

The needs of human beings are increasing day and day. Hence, they modify natural environment to fulfil these needs. Sometimes they even destroy their environment.
Human beings have made cars for their convenience. These cars release fumes which pollute the air. They have established factories on land. These factories manufacture various items such as containers. This is how they modify natural environment.