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Natural Resources



Question (1): How do you classify our natural resources?
Answer: We can classify our natural resources into two categories: (a) Inexhaustible resources: Renewable resources such as solar radiation, air and water. (b) Exhaustible resources: Non-renewable natural resources which are available in limited quantities. e.g., coal, petroleum

Question (2): List the measures adopted to control pollution.
Answer: Pollution can be controlled by adopting the following measures: Solid organic wastes such as garbage and faecal matter should be changed into compost Garbage and silt of drainage may also be used in sanitary land-fill for the development of waste lands Biogas plants should be installed to deal with dung of cattle and other animals Complete combustion engines and anti-smog devices should be fitted in automobiles For avoiding water pollution the fertilizers, herbicides and pesticides should be used judiciously in the crop fields Water hyacinth can be exploited to control water pollution. This weed is found to accumulate heavy metals, radioactive metals, nitrogen, phosphorus and similar chemical pollutants from the waste water. This plant is recently found to be a good source of fodder, fertilizer and biogas.

Question (3): What are the sources of air pollutions?
Answer: Some common sources of air pollution are: Carbon dioxide Carbon monoxide Oxides of sulphur Oxides of nitrogen Fluoride compounds Metals (e.g., lead, cadmium, nickel, arsenic, tin etc) Hydrocarbon (e.g., benzene) Particulate matter Pollen grains Petrochemical products

Question (4): How are the forests useful to mankind?
Answer: Forests are useful to us for the following reasons: Forests provide timber for buildings and furniture, and cane for cane-furniture Forests provide raw materials for the paper industry, board industry, plywood industry etc. Forests provide fodder for cattles, sheep, goat and camels Industrially bamboos are used as raw materials in paper and rayon industry Forests help in balancing the CO₂ and O₂ of the atmosphere Forests regulate the Earth's temperature and weather cycle. They enhance local rainfall. Forests check soil erosion, landslides, shifting of sand and silting of water bodies Forests provide various minor forest products such as fruits, nuts, gums, resins, tannins, rubber, dyes, fibres, medicines, katha, insecticides, camphor, essential oils, soap substances, cooking oils and spices.

Question (5): What are Biosphere reserves?
Answer: Biosphere reserves are multipurpose protected areas with major objectives such as: Conservation of diversity and integrity of plants Promotion of ecological conservation Creation of awareness about environmental aspects and eco friendly living Twelve such reserves have been created in our country. Some of them are Nilgiri, Nandadevi, Sunderbans and Manas.

Question (6): Explain briefly why man is trying to use more and more of solar energy in place of petroleum or coal.
Answer: Petroleum and coal are non-renewable natural resources of energy. When they are burnt, they release energy but they cannot be got back and they also pollute air, water and land. Solar energy is free of cost, is in plenty and creates no pollution. The main advantage is that it is renewable. So, man is trying to use more and more of solar energy in place of petroleum or coal.

Question (7): What direct value does a forest have for man?
Answer: Forests contribute to the economic development of our country by providing goods and services to the people and industry. They are intimately linked with our culture and civilization. Forests are useful to us for the following reasons: Forests provide timber for the building and furniture Forests provide raw materials for the paper industry, board industry, plywood industry etc. Forests yield bamboos, which is called poor man's timber. Industrially bamboos are used as a raw material in paper and rayon industry. Forests provide various minor forest products such as fruits, nuts, gums, resins, tannins, rubber, dyes, fibres, medicines, katha, insecticides, camphor, essential oils, soap substances, cooking oils and spices. Forests also provide various animal products such as lac, honey, wax, tusser or mooga silk etc.

Question (8): What are the harmful effects of ultraviolet radiations?
Answer: Harmful effects of ultraviolet rays or radiations are: Cataract - a disease of eye lens where a normally clear eye lens becomes opaque causing blindness. Inflammatory disease Skin cancer and other types of cancers

Question (9): Write a short note on the fertility of soil.
Answer: The capacity of the soil to sustain the plant life with required nutrients is called the fertility of the soil. The fertility of soil reduces mainly due to soil erosion. When a crop is grown on the same land repeatedly, fertility of the soil decreases. In nature, the soil fertility is sustained both by human efforts and natural processes. The soil is therefore termed as maintainable natural resource.

Question (10): Into how many zones is our country divided on the basis of intensity of rainfall?
Answer: In our country, the intensity of annual rainfall varies from region to region and accordingly, we have 4 zones: Wet zone: Rainfall over 200 cm Intermediate zone: Rainfall 100 to 200 cm Semi arid zone: Rainfall 50 to 100 cm Arid zone: Rainfall 20 to 50 cm

Question (11): What is green house effect?
Answer: The CO₂ molecules of the atmosphere absorb solar radiation and keeps the Earth warm, much like the glass which keeps the green house warm. This effect is called green house effect. The increase in carbon dioxide in the atmosphere has intensified the green house effect and has led to global warming.

Question (12): Write a brief note on: New technologies for producing energy.
Answer: Many industries and laboratories in our country are being involved in development of non-conventional energy sources such as hydrogen energy. Hydrogen is the primary fuel for hydrogen based fuel cells and power plants. Hot springs are used to generate power and also for direct heat application. The temperature gradient, waves and tides in the ocean can be used to generate electricity. With the successful technological development in harnessing the tidal energy, wave energy technology is being used.

Question (13): Which metals are used to obtain nuclear energy?
Answer: The nuclear or atomic energy is produced by the nuclear reaction occurring in metals like uranium and thorium.

Question (14): What are the practices, which replenish the depleted soil?
Answer: There are 4 main practices, which replenish the depleted soil by putting back the lost plant nutrients. They are as follows: Replenishment of soil by crop rotation Different types of crops having different requirements are grown alternatively in the same soil, so that the soil is not depleted of any particular nutrient all the time. Example: Leguminous crops sown in between the cereal crops. Replenishment of soil by multiple cropping/mixed cropping Two crops are properly chosen and grown together. The products and waste materials from one crop plant help in the growth of the other crop plant and vice-versa. This is mixed cropping. Replenishment of soil by keeping the field fallow When the soil of crop fields is kept free or uncultivated for a season or two, then the growth of humus in the soil increases, which in turn promotes the growth of soil bacteria leading to a rich replenishment of plant nutrients in the soil. Replenishment of soil by addition of manures and fertilizers The manures and fertilizers contain necessary plant nutrients. So when we add manures, biofertilizers and chemical fertilizers to the soil, they supply all the necessary plant nutrients to the soil and in this way, the soil gets replenished with nutrients and becomes fertile once again.

Question (15): How is soil formed?
Answer: Soil is formed by the interaction between the physical components (weathering of rocks by rain, wind and temperature) and the biological components (plants, animals, microbes).

Question (16): Define water-table.
Answer: The upper level of the zone of saturation is called the water-table.

Question (17): What is the percentage of oxygen in the air?
Answer: Oxygen constitutes 21% of air in the atmosphere.

Question (18): What is the full form of IUCN?
Answer: The full form of IUCN is International Union for Conservation of Nature.

Question (19): Name any 4 endangered animals of India.
Answer: Endangered animals of India are Lion tailed macaque, Indian rhinoceros, Asiatic lion, Blue whale.

Question (20): Name any 2 non-renewable natural resources.
Answer: Coal and petroleum are 2 non-renewable natural resources.

Question (21): Give 4 examples of inexhaustible natural resources.
Answer: Solar energy, tidal energy, wind energy, nuclear energy are 4 examples of inexhaustible natural resources.

Question (22): List out the different types of soil.
Answer: Soil is classified on the basis of its nature and composition into 6 main types. Namely: Alluvial soil which is rich in loam and clay Black soil which is predominantly clay Red soil which may sandy to loam Mountain soil which is a stony, sandy soil Desert soil which is sandy and poor in organic carbon Laterite soil which is a porous clay rich in iron and aluminium hydroxides

Question (23): Which element is used to obtain nuclear energy?
Answer: Uranium is used to obtain nuclear energy.

Question (24): What is flora and what is fauna?
Answer: These are the technical terms used for plant species and animal species respectively.

Question (25): What is pollution?
Answer: Pollution can be defined as undesirable change in the physical, chemical and biological characteristic of water, air and soil.

Question (26): What are pollutants?
Answer: Pollutants are the substances which causes undesirable change in physical, chemical and biological characteristic of air, water and land. Examples: CO₂, SO₂, CO, oxides of nitrogen, detergents etc.

Question (27): What type of pollution is caused by sewage?
Answer: Water pollution is caused by sewage.

Question (28): What is full form of OTEC?
Answer: The full form of OTEC is Ocean Thermal Energy Conversion.

Question (29): Which zone of atmosphere contains ozone layer?
Answer: Stratosphere zone of atmosphere contains ozone (O₃) layer.

Question (30): What are the measures adopted to protect soil from erosion?
Answer: Soil erosion should be protected by adopting the following principles: Prevention of water from concentrating and moving down the slopes. This is done by contour bunding. Slowing down the water movement when it flows along the slopes. This is done by gully plugging. Encouraging more seepage of water in the soil Reducing the wind velocity near the ground by growing vegetation cover, ridging the land. Increasing the size of soil particles Growing the strips of stubble or other vegetation cover, which help to catch and hold the moving particles of soil.

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Natural Resources

	Introduction
	Types of Natural Resources
	Water
	Air
	Soil
	Minerals
	Energy
	Types of Non-conventional Energy Resources
	Flora and Fauna
	Management and Replenishment of Natural Resources
	Conservation of Forests
	Conservation of Wild Life
	Public Awareness Programmes
	Soil Conservation
	Question and Answers
	Multiple Choice Questions

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