Exercise : Solutions of Questions on Page Number : 22
NCERT Solutions for Class 8 Social Science Resources and Development part-3 Chapter 2
Q1 : Answer the following questions.
(i) Which are the two main climatic factors responsible for soil formation?
(ii) Write any two reasons for land degradation today.
(iii) Why is land considered an important resource?
(iv) Name any two steps that government has taken to conserve plants and animals.
(v) Suggest three ways to conserve water.
Answer :
(i)Temperature and rainfall are the two main climatic factors responsible for soil formation.
(ii)Deforestation and the indiscriminate use of chemical pesticides and fertilisers in agricultural lands are two factors contributing to land degradation.
(iii)Land is among the most important natural resources. It provides habitation to a wide variety of flora and fauna. Human beings use land for various purposes such as agriculture, forestry, mining, building houses and roads, and setting up industries.
(iv) Two steps that the government has taken to conserve plants and animals:
(a) Has set up national parks, wildlife sanctuaries and biosphere reserves for protecting natural vegetation and wildlife; for example, the Kaziranga National Park in Assam.
(b) Has banned the killing of lions, tigers, deer, great Indian bustards and peacocks. It has also prohibited the trade of the species of plants and animals protected under the international agreement CITES.
(v)Three ways to conserve water:
(a) Rain-water harvesting
(b) Reducing wastage of water
(c) Replenishing ground water by promoting afforestation
Q2 : Tick the correct answer.
(i) Which one of the following is nota factor of soil formation?
(a) Time (b) Soil texture (c) Organic matter
(ii) Which one of the following methods is most appropriate to check soil erosion on steep slopes?
(a) Shelter belts (b) Mulching (c) Terrace cultivation
(iii) Which one of the following is not in favour of the conservation of nature?
(a) Switch off the bulb when not in use
(b) Close the tap immediately after using
(c) Dispose polypacks after shopping
Answer :
(i)Which one of the following is nota factor of soil formation?
(a) Time (b) Soil texture
(c) Organic matter
(ii)Which one of the following methods is most appropriate to check soil erosion on steep slopes?
(a) Shelter belts (b) Mulching (c) Terrace cultivation
(iii)Which one of the following is not in favour of the conservation of nature?
(a) Switch off the bulb when not in use
(b) Close the tap immediately after using
(c) Dispose polypacks after shopping
Q3 : Match the following.
| (i) Land use | (a) Prevent soil erosion |
| (ii) Humus | (b) Land suitable for agriculture |
| (iii) Rock dams | (c) Productive use of land |
| (iv) Arable land | (d) Organic matter deposited on top soil |
| – | (e) Contour ploughing |
Answer :
| (i) Land use | (c) Productive use of land |
| (ii) Humus | (d) Organic matter deposited on top soil |
| (iii) Rock dams | (a) Prevent soil erosion |
| (iv) Arable land | (b) Land suitable for agriculture |
Q4 : State whether the given statements are true or false. If true, write the reasons.
(i) Ganga-Brahmaputra plain of India is an overpopulated region.
(ii) Water availability per person in India is declining.
(iii) Rows of trees planted in the coastal areas to check the wind movement is called intercropping.
(iv) Human interference and changes of climate can maintain the ecosystem.
Answer :
(i) Ganga-Brahmaputra plain of India is an overpopulated region.
This statement is true. Plains and river valleys offer suitable land for agriculture. Hence, these are densely-populated areas of the world.
(ii) Water availability per person in India is declining.
This statement is true. Though water is present in abundance, fresh water is a scarce resource. Water availability is a serious problem in many regions of the world. Due to the wastage of water, deforestation, and the pollution and depletion of fresh water reserves (such as rivers and ground water), the availability of water is fast declining.
(iii) Rows of trees planted in the coastal areas to check the wind movement is called intercropping.
This statement is false. The described process is called shelter belts.
Intercropping is the process in which different crops are grown in alternate rows, and are sown at different times to protect the soil from rain wash.
(iv) Human interference and changes of climate can maintain the ecosystem.
This statement is false. Human interferences and climatic changes for the most part adversely affect the balance of the ecosystem.