NIOS Class 12 Biology Chapter 26 Conservation and Use of Natural Resources

NIOS Class 12 Biology Chapter 26 Conservation and Use of Natural Resources Solutions to each chapter is provided in the list so that you can easily browse throughout different chapters NIOS Class 12 Biology Chapter 26 Conservation and Use of Natural Resources Notes and select need one. NIOS Class 12 Biology Chapter 26 Conservation and Use of Natural Resources Question Answers Download PDF. NIOS Study Material of Class 12 Biology Notes Paper 314.

NIOS Class 12 Biology Chapter 26 Conservation and Use of Natural Resources

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Also, you can read the NIOS book online in these sections Solutions by Expert Teachers as per National Institute of Open Schooling (NIOS) Book guidelines. These solutions are part of NIOS All Subject Solutions. Here we have given NIOS Class 12 Biology Chapter 26 Conservation and Use of Natural Resources Solutions, NIOS Senior Secondary Course Biology Solutions for All Chapter, You can practice these here.

Conservation and Use of Natural Resources

Chapter: 26




1. Given below are certain wrong statements. Identify the mistake and write the correct statement below each.

(i) Plastic is a natural resource.

Ans: Plastic is an artificial resource.

(ii) Forest is an exhaustible non-renewable resource.

Ans: Forest is an exhaustible renewable resource.

(iii) The exhaustible resources, which are not replaced after consumption are known as renewable resources.

Ans: The exhaustible resources, which are not replaced after consumption are known as non-renewable resources.


The exhaustible resources which are replaced after consumption, are known as renewable resources.

2. Classify the following under the three respective categories of natural resources:

Air, iron, sand, petroleum, wind, clay, fish, forest, gold, pearls.

(i) Inexhaustible.

(ii) Renewable. and 

(iii) Non-renewable.


(i) In exhaustive Resources(ii) Renewable Resources(ii) Non-renewable Resources


1. Why should we conserve natural resources? State any two reasons.

Ans: Two reasons to conserve natural resources are:

(a) To maintain ecological balance for supporting life.

(b) To preserve different kinds of species.

2. Given below are certain incomplete words. Complete them by taking clues from the statement given below for each. Each blank space represents one letter only.

(i) ___ ___ ___ pk ___. (A movement started by women to stop the felling of trees by hugging them)

Ans: Chipki.

(ii) T___ ___ ___ i. (A sacred plant worshipped in India) 

Ans: Tulsi.

(iii) Kh ___ ch ___ ___ pa ___ ___ i. (A lake in Sikkim that was declared sacred by the people)

Ans: Khecheopatri. 


1. How do the following cause soil erosion?

(i) Wind.

Ans: Wind: Strong wind carries away the loose top soil.

(ii) Overgrazing.

Ans: Overgrazing: It removes the protective vegetation, thus help in erosion by wind and water.

(iii) Water. 

Ans: Water: The rain drops carry away the soil not covered by vegetation.

2. Match the items of Column A with those of Column B.

Column AColumn B
(i) Terracing(a) Decayed vegetable or animal matter
(ii) Erosion(b) Cutting down forests
(iii) Deforestation(c) Practised in hilly areas 
(iv) Humus(d) To wear away


Column AColumn B
(i) Terracing(c) Practised in hilly areas 
(ii) Erosion(d) To wear away
(iii) Deforestation(b) Cutting down forests
(iv) Humus(a) Decayed vegetable or animal matter


1. Why do we consider fresh water as a renewable resource?

Ans: Because it is produced continuously through the hydrological cycle.

2. Give three methods of water conservation.

Ans: Three methods of water conservation are as under:

(i) By constructing dams and reservoirs.

(ii) rainwater harvesting and By judicious use of water.


1. Some of the following words/terms are related to conservation of biodiversity and some are threat to biodiversity. Identify the points relating to conservation by mentioning ‘C’ and threat to biodiversity by mentioning ‘T’ against the points.

(i) Wildlife sanctuaries (_________)

Ans: C.

(ii) Population explosion (_________)

Ans: T.

(iii) Industrialisation (_________)

Ans: T.

(iv) Zoo (_________)

Ans: C.

(v) Tissue culture (_________)

Ans: C.

(vi) Pollution (_________)

Ans: Τ.


1. What is Red Data Book?

Ans: Red Data Book is published by IUCN It provides information about endangered plants and animals.

2. Define the term ‘Wildlife’.

Ans: Plants, animals as well as microbes other than cultivated plants and domesticated animals make wildlife.

3. Below are certain incomplete words. Complete them by taking clues from the statement given below for each. Each blank represent the letter only.

(i) A ___ ___ or ___ ___ ___ at ___ on. (Tree planting programme).

Ans: Afforestation.

(ii) Be ___ ___ ado ___ ___ a. (An endangered Indian plant). 

Ans: Bella donna.

(iii) Rh ________ no _________ r _______ (An endangered animal). 

Ans: Rhinoceros.


1. Expand the following:

(i) WWF. 

Ans: WWF: World Wildlife Fund.

(ii) CITES.

Ans: CITES: Convention of International Trade in Endangered Species. 

(iii) IUCN.

ANs: IUCN: International Union for Conservation of Natural Resources.

2. Match the items of column A with those of column B.

Column AColumn B
(i) Periyar Sanctuary(a) Rajasthan
(ii) Kanha National Park(b) Orissa
(iii) Similipal National Park(c) Uttaranchal
(iv) Bharatpur Bird sanctuary(d) Kerala
(v) Corbett National Park(e) Madhya Pradesh


Column AColumn B
(i) Periyar Sanctuary(d) Kerala
(ii) Kanha National Park(e) Madhya Pradesh
(iii) Similipal National Park(b) Orissa
(iv) Bharatpur Bird sanctuary(a) Rajasthan
(v) Corbett National Park(c) Uttaranchal


1. A and B are two friends. In their daily life both have different opinion on certain matters. Considering the necessity of sustainable development give your suggestions in the given space.

(i) A says — Polythene bags should be used to carry vegetables.

(ii) B says — Jute bags should be used to carry vegetables.

Who is right and why?

Ans: B is right, as the jute bags are biodegradable and eco-friendly. The science has invented the biodegradable polythene bags, but all are not biodegradable. Therefore they cause pollution.

2. Mention any two activities which will help in sustainable development.

Ans: (i) Judicial use of natural resources. 

(ii) Conservation of nature and its resources.


1. Coal is a non-renewable source of energy whereas wood charcoal is renewable. Why?

Ans: The coal cannot be regenerated after consumption. The wood charcoal is obtained from wood. The wood can be obtained continuously from trees of the forest.

2. How are the following useful in our day to day life?

(i) CNG.

Ans. CNG = It is used for cooking and transportation.

(ii) PNG.

Ans. PNG = It is used for cooking.

(iii) LPG.

Ans: LPG = LPG is used for cooking, Ligh-tening and transportation. 

3. A and B are two friends. In their daily life both have different opinion on certain matters. Considering the necessity of sustainable development give your suggestions in the given space.

A says: Coal should be used as fuel to cook our food.

B says: LPG should be used as a fuel to cook our food.

Who is right and why?

Ans: B is right. The LPG causes less pollution than coal.


1. Why do we consider sun as the best source of energy?

Ans: Sun energy is available free of cost and in ample quantity, everlasting. This has no boundaries. This is also free from political barriers.

2. What is meant by ‘radioactive pollution’?

Ans: If the radioactive elements are not disposed off properly they cause disintegration in soil and water and hence cause pollution.

3. What are the advantages and disadvantages of nuclear energy?

Ans: Our country (India) has sufficient thorium to generate electricity (nuclear energy) but it causes pollution.

4. The following table contains the different sources of energy and their uses. Put a tick (✔) mark under the source against the appropriate use(s)

(i) Generation of Electricity
(ii) Fuel for Cooking
(iii) Fuel for Vehicles


(i) Generation of Electricity
(ii) Fuel for Cooking
(iii) Fuel for Vehicles

5. Mention any three ways of conservation of electric energy at your home.

Ans: Three ways of conservation of electric energy at home are:

(i) Judicious use of electricity.

(ii) Use of floroscent lamp instead of incandescent lamp. and 

(iii) Create awareness about the proper use of electricity.


1. Define conservation.

Ans: Conservation: It is defined “as the sum total of activities, that can derive benefits from natural resources but at the same time prevent excessive use that can lead to destruction/neglect”. 

2. What is meant by soil erosion?

Ans: Soil erosion: It literally means “to wear away”. It is defined as “the removal of top layers of soil by the water and wind”. Humus and mineral salts are contained in the upper top layers of the soil.

3. Define the term biodiversity.

Ans: Biodiversity: It is “the variety of all the plants, animals and the microbes of a region.” This is essential to maintain ecosystems.

4. State the meaning of sustainable development.

Ans: Sustainable Development: It is defined as “the development which meets needs of present generation and conserves it for future generation also”.

5. Mention any two methods of conservation of energy resource.

Ans: Demand for energy and exploitation of energy sources is increasing now-a-days; so the energy sources are depleting fast. Hence, there is an urgent need to conserve energy by following two methods:

(i) Stop the wastage of the energy immedia-tely and use biomass based energy.

(ii) Always use renewable source of energy and you create awareness among people to use energy judiciously.

6. Why should wildlife be conserved?

Ans: The endangered species are reduced in number and facing a high risk of extinction in the near future. The plants, animals as well as microorganisms (other than cultivated plants and domesticated animals) constitute wildlife It forms an important resource for maintaining ecological balance to support life. Wildlife is used in research as experimental material. It is also used for recreation. It is essential to maintain biodiversity.

7. Why is soil considered as both renewable and non-renewable resource? 

Ans: The soil is “the uppermost layer of earth’s crust, that supports growth of plants.” Soil is both a renewable and non-renewable resource. There are two reasons of it:

(i) The soil is a renewable since its productivity is maintained by fertilisers and manures rich in black humus.

(ii) The soil may be removed from some place by air or wind, it is practically non-renew-wable because the formation of new soil can take hundreds and thousands of years. 

8. State any three reasons for degradation of water.

Ans: Three Reasons for Degradation of Water:

(i) The industrial effluents are dis-charged in river water before being treated properly.

(ii) The sewage water is mixed or discharged with fresh water body. Agricultural wastes having pesticides, fertilisers enter into water bodies to degrade water quality. 

(iii) The quality of fresh water is degraded when clothing, bathing etc are done in ponds, lakes and rivers.

9. Distinguish between in-situ and ex-situ conservation strategies.

Ans: Difference Between Ex-situ and In situ Conservation:

Ex-situ ConservationIn-situ Conservation
1. Called off-site conserva-tion.Called In-situ or on-site conserva-tion.
2. It includes zoos, botanical gardens, gene banks, pollen banks, conserva-tion strands and seedling DNA banks etc.Carried out by biosphere reserves, national parks and wildlife sanctuaries as well as protected areas and the forests also to protect endangered species in natural habitat.
3. Involves handling, col- lecting, management, research of germ-plasm storage, regeneration characterisation, evalua- tion, documentation, disse-mination etc.Helps to conserve in-situ all forms of life and their support systems, to monitor and evaluate changes in natural eco- systems. Sacred forests and sacred lakes help in it.
4. In India there are 35 botanical gardens, 275 zoos, deer parks, safari parks and aquaria etc.There are 425 biosphere reserves in world. Out of these 14 are in India.

10. Describe natural gas as conventional source of energy.

Ans: Natural Gas: It occurs with petroleum. It contains methane (CH₄). It is used in houses in India. It is supplied by pipe lines in big cities and called as PNG (piped natural gas). CNG is used as fuel for running vehicles e.g., car, bus etc. It is less polluting gas. LPG is a mixture of butane plus propane.

11. Describe the natural and the anthropogenic causes of soil erosion.

Ans: (A) The natural causes of soil erosion are as follow:

(i) Water: Deforestation causes floods and rain drops carry away the soil particles.

(ii) Wind: High velocity and strong winds carry away the loose top soil.

(B) Human generated causes of soil erosion are:

(i) Overgrazing by animals lessen the plant cover on the soil.

(ii) Poor farming methods such as improper tillage and burning of weeds reduce the water holding capacity of soil.

12. Describe the various methods of conservation of soil.

Ans: Methods of soil conservation: Soil conservation is checked by the control of grazing, reforestation, terracing, contour ploughing and by maintaining the fertility of soil.

(i) Reforestation: Trees should be planted to reduce soil erosion.

(ii) Terracing: The slopes should be divided into small terraces. They control rapid flow of water.

13. Future generations of mankind will depend more and more on non-conventional sources of energy. Discuss.

Ans: Non-conventional sources of energy are solar energy, hydropower, wind energy etc. Conventional sources of energy like petroleum, coal and natural gas are depleting very fast. In future these sources are not available. So non-conventional. Sources will be used by future generations, to meet their demand.

14. Explain any five methods of conservation of water.

Ans: Methods of Conservation of Water: It can be achieved by adopting following methods:

(a) By judicious use of water in our daily use we can save water.

(b) The sewage must be treated before being released into the rivers and streams.

(c) Rainwater harvesting is another method to store rainwater and recharg- ing groundwater.

(d) By constructing dams and reservoirs the water supply to fields can be regu- lated as well as to enable generating hydroelectricity.

(e) By growing vegetation in catchment areas, we can contribute to formation of ground water.

15. Describe any three non-conventional sources of energy.

Ans: Non-Conventional Energy Sources include hydel energy, solar energy, wind energy, hydrogen energy, nuclear energy, geothermal energy, biogas energy, biofuel and the tidal energy.

(i) Hydrogen energy: It is primary fuel for hydrogen based cells as well as power plants. It is used in industries, houses and transportation purposes.

(ii) Bio-gas: It is formed by activity of microbes on the cattle/cow dung in the digester (tank). It contains methane (50-55%). The waste left in tank is used as manure. Two kinds of biogas plants are:

(i) family type. and 

(ii) the comm-unity type.

(iii) Biofuel: It is obtained from petro-plants. The plant Jatropha curcus yields biodiesel that is safer and its emmission has less CO, SO₄, HCs etc.

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