MP Board Class 9th Social Science Solutions Chapter 1 Man and Environment

MP Board Class 9th Social Science Chapter 1 Text Book Questions

Choose the Correct Answer:

Question 1.
Unit of measuring noise is:
(a) Centimetre
(b) Decibel
(c) Celsius
(d) Millibar
Answer:
(b) Decibel

Question 2 .
City with the highest intensity of noise in the world –
(a) Mumbai
(b) New York
(c) Rio-de-Janeiro
(d) Tokyo.
Answer:
(c) Rio-de-Janeiro

Question 3.
Where was the ozone hole observed in 1985?
(a) Australia
(b) Antarctica
(c) Western Europe
(d) Alaska.
Answer:
(b) Antarctica

Question 4.
Ozone layer is-
(a) 20-35 km above the earth’s surface
(b) 5-10 km above the earth’s surface
(c) 75-100 km above the earth’s surface
(d) 32-80 km above the earth’s surface
Answer:
(d) 32-80 km above the earth’s surface

Question 5.
Main cause of environmental degradation is –
(a) Increase in tourism
(b) Shifting cultivation
(c) Changing nature of land use
(d) All the above
Answer:
(d) All the above

Question 6.
Population explosion is –
(a) Migration
(b) Equal death rate and birth rate
(c) Crowding
(d) Continuous increase in number of humans.
Answer:
(d) Continuous increase in number of humans.

Question 7.
Cut and Burn is related to –
(a) Shifting cultivation
(b) Tourism and pilgrimage
(c) Mining
(d) Construction of dam.
Answer:
(a) Shifting cultivation

MP Board Solutions

Fill in the blank:

  1. Any physical thing or matter, which is valuable to man is called ……………
  2. …………… % of the earth is landmass and is covered with water.
  3. ……………….. % of the total land area of the world is covered by forest.
  4. The term ‘acid rain’ was first coined by a British scientist in ………………

Answer:

  1. environment
  2. 29, 71
  3. 30
  4. 1873

MP Board Class 9th Social Science Chapter 1 Very Short Answer Type Questions

Question 1.
What do you mean by environment?
Answer:
All that surrounds us is our environment. Environment consists of’ all living and non – living matters that exist around us. ‘ There is a close relationship between man and environment. Man is born in his special environment and passes his entire life in the same environment.

Question 2.
What is the meaning of cultural environment?
Answer:
This environment develops due to the mutual relationship ‘ between man and natural environment. This includes the economic and social activities created, developed and conducted by man such as farming, industry, rites and rituals, settlement, roads, railways, air services, means of irrigation, government system and science and technology.

Question 3.
Name five polluted rivers of India?
Answer:
The Ganga, Hugli, Damodar, Yamuna, Godawari.

Question 4.
What is global warming?
Answer:
Due to the hole in the ozone layer the wrath of ultraviolet rays on the earth surface is increasing. Carbon-dioxide and other heat resistant gases absorb some part of heat and reverse it back to the earth surface. As a result extra heat is stored in the lower atmosphere and its temperature increases which is called global warming.

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MP Board Class 9th Social Science Chapter 1 Short Answer Type Questions

Question 1.
How does air or noise pollution affect human health? Explain.
Answer:
Effects of air pollution on health:
Gases from .industries containing sulphur dioxide, carbon dioxide and phosphorus oxide etc. are harmful suffocating to us. Air pollutants have adverse effect on plant life. The poisonous gases also enter plant tissue of leaves and disturb their physiology. Plants living in polluted conditions suffer poor growth, delayed flowering and maturation of fruits.

Effects of noise pollution on health:
The problem of noise pollution is very acute in urban areas due to sound produced by different vehicles, machines, transistors and radios, drum beats on religious and wedding procession amplified rock music and discos etc.

Constant exposure to this sound produces deafness, increase in nervous tension, blood pressure and causes heart troubles.. It also causes headaches, irritability and affects the sensory and nervous system.

Question 2.
How do radioactive substances spread pollution?
Answer:
During the use of nuclear elements for various purposes the radioactive particles enter the atmosphere and produce radio active pollution. Radioactive pollution have both direct and indirect effects on our body. Radioactive radiation directly enters our body via respiratory track in the form of air and gases. Indirectly it influences our body through food chain. The radioactive substance such as strontium destroys fertility of soil.

Question 3.
Differentiate between pollution and pollutants?
Answer:
1. Pollution:
The unwanted change occurring in the natural formation and balance of the environment is known as environmental pollution.

2. Pollutants:
The unusable substances responsible for pollution which are present in improper quantity are called pollutants.

Question 4.
Explain the problem of ozone depletion?
Answer:
From 30 – 80 km above the earth surface there is a 50 meter thick layer of ozone. This layer absorbs the ultraviolet rays coming from the sun and this saves the living beings on the earth. Due to the excessive use of Chloro Floro Carbon (CFC) in the appliances such as refrigerator and air conditioner, there is a hole in ozone layer.

Due to this hole tire wrath of ultraviolet rays on the earth surface is spreading. As a result the possibility of skin cancer is increasing. It also reduces the immunity of human body. Due to the decreasing rate of photosynthesis growth of flora and fauna is hampered and forests are drying.

Question 5.
what is soil pollution? What are its ill – effects?
Answer:
Any unwanted change in the physical, chemical or biological attributes of the earth which destroys the fertility and utility of land is soil pollution.

Ill – effects of soil pollution:

  • Soil pollution and bitter make the visible land dirty.
  • Due to the deposition of the waste or coarse material the land becomes unsuitable for other uses.
  • There is danger of soil erosion, land sliding and conversion of land into ravines.

Question 6.
What do you understand by population explosion?
Answer:
When the population of country rises at such a fast speed that existing resources of the Country fall short of the necessary requirement of the people, it is called stage of ‘population explosion This has created many problems such as crowd, unemployment, security of resources, pollution, mental and social tension etc.

Question 7.
How does over gradation affect the quality of land?
Answer:
Excessive intake of vegetation by domestic animals is called excessive grazing. As a result cf excessive grazing the vegetation does not grow again very fast in these areas. The layer of vegetation from land is destroyed. Due to soil erosion the danger of desertification arises. In such areas soil absorbs less water and plants do not get adequate water.

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Question 8.
Describe the process of shifting agriculture?
Answer:
Shifting agriculture is an old method of cultivation. In this method trees are cut and burnt and then the land is prepared for farming. But this type of land is used for farming for some time and then discarded. But this method of farming has made enough harm to the forests.

Question 9.
What is deforestation? List the reasons of deforestation.
Answer:
Deforestation means cutting forests or plants from some region. Reduction of forest is the result of human effects.

Reasons of deforestation:

  • Construction of huge dams.
  • Throwing of hydro – electricity projects.
  • Distribution of electricity and spread of railways and roads.
  • Extension of habitat areas.
  • Cutting of trees for fuel.
  • Spreading of industries.

Question 10.
Insecticides should not be used in excess amount. Why?
Answer:
It has become a common practice to use plenty of in – pesticides to enhance production. As a result the nutrients of the soil are reduced. The fertility of soil is also hampered. The quality of production is affected.

Question 11.
What are the harmful effects of mining on the environment of a region?
Answer:
Excessive mining means digging of land for extracting minerals and other substances. Trees are being cut from the land. As a result circulation of underground water is hampered, land sliding, deposition of waste material, soil erosion and formation of new’ land forms occur. The ill – effects of excessive mining can be observed in Doon valley formed by Ganga – Yamuna which are surrounded by Himalaya ranges.

Previously this valley area was world famous for the production of Basmati rice, litchi and tea. But now due to uncontrolled mining of lime stone only 12% valley area has greenery. In the Jaipur, Jodhpur and Udaipur districts due to mining of stones the surrounding greenery has been destroyed.

Question 12.
How does urbanization destroy the environment?
Answer:
As a result of urbanization there is increase in population density and transport facilities, roads, railways, hospitals, community centers etc. are on rise. All these increase the pollution. The increasing deposition of waste influences the environment also.

MP Board Class 9th Social Science Chapter 1 Long Answer Type Questions

Question 1.
Explaining the Indian concept of environment describe how man is related to his environment?
Answer:
There has always been a mutual relationship between man and nature. We can find proof in regard in our ancient literature too. Nature is represented in the form of mother in Vedas. In the hope of healthy environment man has maintained passionate relations with the environment in his life-style. His debt towards environment is exposed in the form of sensitivity, honor, passion, and safety.

Man and environment are the creator, parent and savior of each other. Nature is considered as the substitute of life. We have always offered our prayers to water sources such as the Ganga, the Yamuna, the Saraswati, plants like the Banyan, Peepal, Neem, and Tulasi. We have always worshiped the Sun, the Moon and the.

Earth. In turn the mother nature has brought up us like her children. It is believed that the environment receives fragrance as we bum Dhoop. The up nishads assume earth as body of the supernatural, heaven as his brain, the Sun and the Moon as his eyes and skies as his mind. Hence, it is not proper to cut trees and pollute sources of water. Thus, we can say that man and environment are closely related with each other.

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Question 2.
What is environment? What are the main elements of environment? How has man affected the environment? Explain.
Answer:
All that surrounds us is our environment. Environment consists of all living and non-living matter that exist around us. There is a close relationship between man and environment. Man is born in his special environment and passes his entire life in the same environment.

Environment may be defined as follows:

  • The environment is all that surrounds mankind and directly or indirectly influences man.
  • All physical elements and biotic elements together constitute environment.

Main Elements of Environment:.
All the elements which effect environment are called the elements of environment. These elements can be classified into major categories.

1. Elements of natural or physical environment:
This includes all natural elements given by the nature such as location, geomorphology, rocks, climate, vegetation, wild life, minerals, water bodies, ocean, etc.

2. Elements of Sociocultural Environment:
The sociopolitical environment develops due to the mutual relationship between man and natural environment. This includes the economic and social activities created, developed and conducted by man such as farming, industry, rites and rituals, settlement, roads, railways, air, services, means of irrigation, government system and science and technology.

3. How has man affected the environment?
Man is at the top of ecological pyramid. He is omnivorous because he. feeds both on plants and animal life. As a result of senseless and. continuous hunting, some species of birds and animals have become extinct and others are leading to extinction. Cultivation of land has had a serious impact on ecosystem.

The removal of original plants covers and its replacement by single cultivated crop reduces the biological diversity and simplifies the ecosystem  making it venerable to pests and diseases which attack crop. Burning of fossil fuel in large quantities, automobile exhausts, gaseous effluents from factories have led to the pollution of air and water.

Humans have cleared the jungles for their dwellings, for rearing animals and for construction roads and buildings. Too much use of land, forests have caused lot of health problems and ecological problems. As a result of pollution of air and water various species of plants have became extinct because pollution of air and water adversely affects plants.

Question 3.
What do you mean by pollution? Describe differ- it types of pollution.
Answer:
Pollution. The undesirable change in the physical, chemical, and biotic elements of the environment which adversely alters the natural quality of the environment is called environmental pollution. Pollution of the environment may occur naturally without the intervention by human being or may be caused by human activities. Volcanic eruptions, forest fires, space disturbances are the examples of pollution’s caused by nature itself. But pollution is mainly caused by human activities due to over-use, misuse, and mismanagement of resources.

Types of pollution:
1. Air pollution:
Disturbance of balance among various gases in the air or presence of unwanted gases is known as air pollution. The burning of fossil fuels in large quantities during the recent ‘ decades had resulted in gradual increase in carbon – di – oxide content in the atmosphere. The increase in carbon – di – oxide leads to increase in temperature.

Burning of coal and oil adds sulphur dioxide to the atmosphere which causes many body aliments including respiratory diseases. Gaseous effluents from factories also pollute the atmosphere. Air pollution is of global significance unlike water or land pollution which are of local or regional effect. These gases also cause acid rain in industrial regions affecting acquainted ecosystem.

The water so polluted cannot support fish or other life forms in water. Acid rain also damages forests. The ozone layer in the atmosphere serves as a shield protecting the earth from ultraviolet radiation. When the ozone layer is depleted, ultraviolet radiation enters the earth surface and may cause skin cancer.

2. Water Pollution:
The entry of some unwanted substances in the natural water that reduces its purity is known as water pollution. Polluted water is not suitable to men, animals, vegetation, sea, animals and irrigation. The causes of water pollution are soil erosion, leaves of trees, domestic drainage, and sewage, effluents from factories, fertilizers and pesticides and the hot water flowing from nuclear reactors and spreading of mineral oil on sea surface. This contaminates the drinking water and causes water born diseases such as jaundice, dysentery, and typhoid. etc. .

3. Noise Pollution:
The disturbance caused by noise or unwanted sound which interferes with human communication, comfort and health etc. is called Noise Pollution. The problem of noise pollution is very acute in urban areas due to sound produced by different vehicles, machines, transistors and radios, drum beats on religious and wedding procession amplifier rock music and discos etc.

Constant exposure to this sound produces deafness, increase in nervous tension, blood pressure and causes heart troubles. It also causes headaches, irritability and affects the sensory and nervous system.To control noise pollution, improvement in the machines, construction of sound barrier and absorbs, should be done. The ear protective devices should be used.

4. Soil Pollution:
Any unwanted change in the physical, chemical or biological attributes of the earth which destroys the fertility and utility of. land is soil pollution. Excessive use of pesticides and fertilizers, industrialization, urbanization, plastic and polythene, continuous irrigation with salted water, etc. are various causes of soil pollution.

5. Radioactive Pollution:
During the use of nuclear elements for various purposes the radioactive particles enter the atmosphere and produce radioactive pollution. The excessive energy released during nuclear test’ destroys human and animal cells.

6. Thermal Pollution:
An unwanted increase in normal temperature in the world which effects biosphere is thermal pollution. Carbon-dioxide, methane, CFC, Nitro-us oxide, ozone hole, forest fire, nuclear tests etc. increase atmospheric temperature. Drought, flood, low agricultural production due to climate change, ozone depletion etc. are some of the ill-effects of thermal pollution.

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Question 4.
What is the meaning of resources? Describe various types of resources with example.
Answer:
All the elements, biological or non – biological, present in nature which are capable of fulfilling human wants are called resources. Land soil, water, air, sun – rays, forests, wild animals, fish, minerals etc. are examples of resources.

All gifts of nature about which man has the knowledge in regard to their use, availability and accessibility are thus called resources. There may be innumerable things hidden in the lap of nature but man may not be knowing about many of them. Thus gifts of nature, about whom man does not know, cannot be called resources.

Various Types of Resources:

  • Natural Resources – Renewable (air, agricultural, water, forest), Non – renewable (non-cyclic fossil fuel, as coal, petrol and cyclic-metallic minerals).
  • Human Resources – (population, health, education and working efficiency).
  • Man – made Resources – (buildings, roads, sociopolitical institution).

1. Renewable Resources:
Resources, which are reproduce-able after the use or can be used again eg. forests, pastures, agricultural land.

2. Non-renewable Resources:
Those resources which once exploited cannot be reproduced or supplied in tire near future such as petroleum, coal.

3. Human Resources:
It means the number and quality of human beings. Education and health increase man’s physical and mental capacity. Man himself is major resource who uses the natural elements as resource on the basis of his knowledge, labor and technical know – how.

4. Man – made Resources:
These are those means of production which are produced by man to utilize the physical matters of environment such as machines, buildings, tools, etc.

5. Land Resources:
It is an important natural resource. Land is used for housing, roads, railways, farming, pasturing and mining, etc.

6. Water Resources:
Water on the earth surface is obtained through rains, rivers, lakes, ponds, glaciers, waterfalls and tube- wells. The water is used for irrigation, industry, domestic supply, fish farming and water transport.

7. Soil Resources:
Good soil is essential for the growth of vegetation.

8. Forest Resources:
Forests are a valuable resources like rivers. Forests provide us many valuable products timber, paper, medicine, firewood, wood pulp, lac, rubber, etc. Forests check soil erosion. Forests prevent floods. Forests provide suitable environment for wild-life. Forests absorb carbon – dioxide and release oxygen to the atmosphere. Forests add water vapor to the atmosphere by the process of transpiration.

Question 5.
How does changing use of land affect the environment? Explain.
Answer:
Man has brought many changes in environment in order to fulfill his ever-growing needs. He has made unnecessary disturbance in natural environment. The major cause of decline of natural environment in the world is changing form of land-use. In India forests are being destroyed for various purposes.

Deforestation and pasturing, construction of big dams for hydro – electricity and irrigation, spread of new roads and railways and development of factories has transformed land – use in India to a great extent. This has disturbed the natural balance.

The continuous interference with environment for the sake of human settlement and industrial and economic development cause environmental deg – radiation. The habitat of various types of animals have been destroyed and thousands species of flora and fauna become extinct.

Question 6.
How does over-population affect human life? Explain.
Answer:
When the population of country rises at such a fast speed that existing resources of the country fall short of the necessity of the people, it is called stage of over – population or population explosion. This has created many problems such as crowd, unemployment, security of resources, pollution, mental and social tension etc.

In the absence of suitable dwelling arrangements people tend to live on fields, streets and lanes. This gives rise to the establishment of jhugg is and subsequent loss to the ecological balance. Over – population has created the problem like overcrowding. It leads to pollution – which leads to many health hazards.

Due to over – population various types of resources are decreasing fast. People cut trees which has created grave situation. People are in race of acquiring more and more material objects. This race has given them mental and social tension. This, over – population has badly affected the human beings. We remain under pressure all the time which may reduce our life span.

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Question 7.
How is the construction of huge dams harmful for the environment? Explain.
Answer:
Dams are being constructed on big rivers for purpose of irrigation, hydro – electricity, canals, fishing, water transportation and flood control. About 700 dams have been constructed after independence. But they are not unbeatable from the point of view of environment. Whenever a river valley project is started the construction of houses for the workers, construction of road, railway and underground tunnels become essential.

As a result the greenery of large areas surrounding the construction site disappears. The artificial pond made from the huge dam drowns forests and farm land. The alkalinity of the land increases due to water drained from the canals of the dam and its fertility decreases. Due to the prevalence of continuous water in dam and canal area the nearby land becomes unsuitable for agriculture. Human settlements are displaced from the dam area. Thus construction of huge dams badly affects our environment.

Question 8.
Centralization of industries is very dangerous for the environment. Explain with examples.
Answer:
Industrialization is helpful to man but harmful to our environment. The factories release poisonous gases in the atmo sphere. This disturbs atmospheric balance and increases air pollution. The waste material are left open in surrounding areas. The polluted water is drained in the river which directly influences human health and environment.

Industrialization is the main source of air, water, noise, land, chemical and radioactive pollution. In the Kolkata metropolis of India the water of Damodar and Hugh rivers have been poisoned by the effluents of surrounding steel factories, chemical industries, distilleries and paper and jute mills. Same is the true with the Ganga, Yamuna and Chambal rivers.

Question 9.
What do you mean by water pollution? River pollution is increasing in India. Describe.
Answer:
The entry of some unwanted substance  in the natural water that reduces its purity is known as water – pollution. Water is being polluted by the humans in different ways.

1. When factories, specially, those of paper mills, sugar mills, tanneries etc. discharge their effluents in rivers or allow them stagnate on land.

2. When there is no river nearby the stagnated effluents seep through the land, mix with the underground water and pollute the water. For example, effluents from large number of tanneries in North Arcot district in Tamilnadu have polluted well water in large number of villages.

3. The most widespread source of water pollution is disposal of sewage of urban centers into river. For example, rivers Ganga, Yamuna are polluted by sewage disposal while these rivers also provide drinking water to the people residing nearly.

This contaminates the drinking water and causes water born diseases such as jaundice, dysentery and typhoid etc. Approximately 90% surface water is polluted in India. The Ganga, Hugh, Damodar, Gomti,t Yamuna, Godawari rivers are polluted due to the industrial and the urban wastes and sewages.

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MP Board Class 9th Social Science Chapter 1 Other Important Questions

Choose the correct answer:

Question 1.
The religion of Christianity considers nature as a –
(a) God
(b) Goddess
(c) Human being
(d) Nature.
Answer:
(b) Goddess

Question 2.
Lord Buddha got enlightenment under –
(a) The Banyan tree
(b) The Peepal tree
(c) The Neem tree
(d) The Jamun Tree.
Answer:
(a) The Banyan tree

Question 3.
Non – renewable resource is –
(a) Coal
(b) Forest
(e) Pastures
(d) Lands.
Answer:
(a) Coal

Question 4.
The total land area of the world covered by forests is –
(a) 50%
(b) 40%
(c) 30%
(d) 65%
Answer:
(c) 30%

Question 5.
The harmful radioactive substance such as strontium destroys –
(a) Fertility of soil
(b) Growth of plants
(c) Growth of a child
(d) None of the above.
Answer:
(a) Fertility of soil

MP Board Solutions

Fill in the blank:

  1. Nature is represent as mother in ………………
  2. Under the …………… did Buddha get enligi.. nunent.
  3. The unit of noise is …………..
  4. Approximately …………… % surface water is poluted in India.
  5. ………… and …………. is related to shifting cultivation.

Answer:

  1. Vedas
  2. Banyan Tree
  3. Decibel
  4. 90
  5. Cut, Burn.

MP Board Class 9th Social Science Chapter 1 Very Short Answer Type Questions

Question 1.
What do you understand by “Man – made environment”?
Answer:
Our cultural environmental is also known as “Man-made environment”. It contains human races, social systems, human habitat and administrative systems. It is different from natural environment but it is effected by natural environment and interact with it.

Question 2.
What are the main causes of air pollution?
Answer:
Main causes of air pollution are following:

  • Increase in population
  • Deforestation
  • Fires
  • Industrialization
  • Increase in vehicular smoke.

Question 3.
Which are the main components of environment? Write their names.
Answer:
Biotic and abiotic, both are main components of environment.

Question 4.
What is called environment?
Answer:
The surroundings around us is known as our environment. In other words, we can say that environment means the areas and surroundings which cover us and we live in.

Question 5.
Write the main uses of water.
Answer:
Water is used for drinking, cooking, food, irrigation, bathing and washing the clothes. –

Question 6.
How much percentage of surface water is polluted in India.
Answer:
Approximately 90% surface water is polluted in Indian

Question 7.
Which city having highest noise in the world?
Answer:
Rio – de – Janeiro is the city having highest noise in the world, where noise pollution is 120 decibel.

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Question 8.
What is the unit of noise?
Answer:
The unit of noise is Decibel.

Question 9.
What is environmental pollution?
Answer:
The undesirable change in the physical, chemical, and biotic elements of the environment which adversely alters the natural quality of the environment is called environmental pollution. Pollution of the environment may occur naturally without the intervention by human being or may be caused by human activities. Volcanic eruptions, forest fires, space disturbances are the examples of pollution’s caused by nature itself. But pollution is mainly caused by human activities due to over-use, misuse, and mismanagement of resources.

MP Board Class 9th Social Science Chapter 1 Short Answer Type Questions

Question 1.
What causes soil pollution?
Answer:
Main causes of soil pollution:

  • Artificial chemical fertilizers and insecticides etc. .
  • Industrial complexes like pulp, paper mills, oil refineries, rubber producing complexes etc.
  • Domestic wastes like broken gadgets, worn out furniture, caves, rags etc.

Question 2.
What will happen if the carbon dioxide content of the air increases?
Answer:
The increase in the carbon dioxide content of the air will result in warming up of the earth. It will cause melting of ice caps and glaciers. This would cause a rise in sea level and violent tidal waves resulting in flooding of the popular coastal plains. It may prove to be an important pollutant in the long run and cause respiratory trouble and direct threat to health.

Question 3.
What are the harmful effects of water pollution?
Answer:
Polluted water causes so many diseases. Jaundice and cholera is caused through contaminated water. As large cities are mainly affected with polluted water so the growth of virus and bacteria etc. get enhanced in these cities and can. the epidemic of jaundice and cholera. Other diseases rela intestinal disorders, liver problems etc.

Question 4.
What is the need of conserving the environment?
Answer:
There is an urgent need for protecting the environment from which man derives his food and other resources. An understanding of the processes which take place in the environment is necessary so that man’s activities, are reorganized in such a manner .so as not to interfere with the environment. Man will have to learn to live in perfect harmony with the physical and biological environment so that the earth continues to be habitable for the future as well.

Question 5.
What is natural environment?
Answer:
Natural Environment:
Natural environment is also called physical environment. It consists of all physical factors bestowed by the nature. Natural environment includes land, climate, minerals and all such endowment without which tire life on earth could have not been possible. It is thus the sum total of all non-living and inorganic matter such as land, air and water. It provides the earth with favorable condition for the existence and growth of life including man.

Question 6.
What is cultural environment?
Answer:
The man – made environment has been included in the cultural environment. The main factors of cultural environment are human races, social systems, human habitat and administrative systems. Through this environment man adapts himself to his physical environment and struggles with the vagaries of nature. His efforts have made him win places which were hitherto untouched by human population. He has succeeded in-exploring the depth of the ocean and height of the mountain.

Question 7.
Define acid rain.
Answer:
The sulphur-dioxide and nitrogen gases coming out of tire factories mix up in the atmosphere, they react with the existing vapors and produce sulphuric acid and nitrite acid respectively. This acid when pours down with the water rains on the earth. It is called the acid ram. The term acid rain was first coined by a British Scientist in 1873.

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Question 8.
Write a short note on ‘Urbanization’.
Answer:
The process of extension of cities is urbanization. As a result of urbanization there is increase in population density and transport facilities, roads, railways, hospitals, community centers etc. are on rise. All these increase the pollution.

The increasing deposition of waste influences human health. About 5 crore people in India reside in the four metropolis of Delhi, Mumbai, Kolkata and Chennai. These cities are suffering from drinking water problem, urban pollution, unemployment and lack of peace.

MP Board Class 9th Social Science Chapter 1 Long Answer Type Questions

Question 1.
Describe the factors which are responsible for the changing form of land all over the world.
Answer:

There are many factors which are responsible for the changing form of land all over the world:
1. Population Growth and Reproduction:
Our population is increasing day by day. As a result we are facing the problem of population explosion. Human life-style has improved due to progress in the field of medicine. The fertility and mortality rates have come down. Deaths are on decline. As a result mortality rate has unexpectedly gone down and population has gone up. Due to unlimited growth in population problems like crowd, unemployment, security of resources, pollution, mental and social tension have come up.

2. Deforestation:
It means cutting forests or plants from some region. Reduction of forest is the result of human effects. All methods of shifting cultivation made enough harm to the forests. Other factors which have harmed forests are construction of huge dams, spread of railways and roads, etc.

3. Excessive Grazing:
As a result of excessive grazing the vegetation does not grow again very fast in these areas. The ill- effect is that layer or vegetation from land is destroyed. Due to soil erosion the danger of desertification arises.

4. Harmful Experiments in Agriculture:
In order to fulfill the ever-increasing demand of food crops of more production are grown. It is a common practice to use plenty of chemical fertilizers, pesticides and weed killing chemicals to en-chance production. Salination increases as a result of inadequate drainage of water from the fields. Nutrients of the soil are reduced due to prevalence of excessive water.

5. Urbanization:
It has increased population density, and transport facilities. Roads, railways, hospitals, community centers etc. are on rise. Some other factors are industrialization and extension of slums and construction of huge dams.

MP Board Class 9th Social Science Solutions

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