CBSE Class 12 Biology Environmental Issues Assignment Set 02

POINTS TO REMEMBER

Pollution : Undesirable physical/chemical/biological characteristics of air/water/ land which cause damage to the animals/plants/humans and architectural structures.

Pollutants : Agents which cause pollution.

Slash and Burn Agriculture (Jhum Cultivation) : Farmers cut down trees and burn the plant remains. Ash is used as a fertiliser and the land is then used for farming or cattle grazing.

Reforestation : Process of restoring a forest that was removed at some point of time in the past.

Effluents : Something flowing over a large body of water (may be sewage or industrial effluents).

CPCB : Central Pollution Control Board

BOD : Biological Oxygen Demand

CNG : Compressed Natural Gas

FOAM : Friends of Arcata Marsh

JFM : Joint Forest Management.

Biochemical Oxygen Demand (BOD)

❑ BOD refer to the amount of oxygen that would be consumed if all the organic matter is one litre of water were oxidized by bacteria. The BOD test measures the rateof uptake of oxygen by micro-organisms in a sample of water.

❑ Indirectly BOD is a measure of the organic matter present in the water. The greater the BOD of waste water, more is its polluting potential.

❑ In the given figure the effect of sewage on some imporant characteristic of a river is shown:

Important Questions for NCERT Class 12 Biology Environmental Issues

Question. Which of the following devices is best for reducing emission of poisonous gases -
(a) Scrubber
(b) Catalytic convertors
(c) Electrostatic precipitators
(d) Filters

Answer : B

Question. The goal of Euro-IV norms, according to roadmap is to reduce sulphur to -
(a) 50 ppm in petrol and diesel
(b) 150 ppm in petrol and diesel
(c) 350 ppm in petrol and diesel
(d) 250 ppm in petrol and diesel

Answer : A

Question. Slash and Burn agriculture are associated with -
(a) Deforestration
(b) Jhum cultivation
(c) Shifting cultivation
(d) All the above

Answer : D

Question. Regarding to composition of waste water which among the following is not true -
(a) Suspended solid - sand, silt & clay
(b) Colloidal matter - faecal matter, bacteria & cloth
(c) Dissolved material - nitrate, ammonia & phosphate
(d) Dissolved material - faecal matter, bacteria & nutrients

Answer : D

Question. Pollutants from man's activities like effluents from industries and homes can radically accelerate the aging of lake, that is known as -
(a) Cultural Eutrophication
(b) Accelerated Eutrophication
(c) Rising Eutrophication
(d) Both (a) & (b)

Answer : D

Question. Integrated waste water treatment plant of town of Arcata is supported by biologists of Humboldt state university, involves -
(a) Conventional sedimentation
(b) Filteration
(c) Series of six marshes
(d) All the above

Answer : D

Question. What is the main problem with switching over to CNG from petrol and diesel ?
(a) High cost
(b) Difficulty of lying down pipelines to deliver CNG for uninterrupted supply
(c) Lack of suitable engines
(d) All the above

Answer : B

Question. Beside use of CNG, simultaneously parallel steps taken in Delhi for reducing vehicular pollution,except-
(a) Use of unleaded petrol
(b) Use of low sulphur petrol and diesel
(c) Use of catalytic convertors
(d) Use of Electrostatic precipitators

Answer : D

Question. Series of six connected marshes over 60 hectares of marshland, with appropriate plants, algae, fungi and bacteria is responsible for -
(a) Neutrilisation of pollutants
(b) Absorbtion of pollutants
(c) Assimillation of pollutants
(d) All the above

Answer : D

Question. Practical ,hygienic efficient and cost effective solution to human waste disposal is -
(a) Eco - San toilets
(b) Natural toilets
(c) Ecofriendly toilets
(d) Ecological sanitation

Answer : D

Question. Open dumps often serve as breeding ground for rats and flies and not burnt to completion. Which among the following were adopted as the substitute for open burning dumps -
(a) Eco san
(b) Electronic Burners
(c) Sanitary Landfills
(d) Solar Burners

Answer : C

Question. Which among the following was developed by company of Ahmed Khan by a fine powder of recycled modified plastic -
(a) Polysterene
(b) Polyblend
(c) Polyethylene
(d) Polyplastic

 Answer : B

Question. Which among the following is a cyclical, zero waste procedure, where waste products from one process are cycled in as nutrients for other processes-
(a) Integrated organic farming
(b) Integrated remedy for plastic waste
(c) Integrated waste water treatment
(d) Sustainable waste treatment

Answer : A

Ques. Which of the following is a secondary pollutant?
(a) CO
(b) CO₂
(c) SO₂
(d) O₃ 

Answer: D

Ques. A renewable exhaustible natural resource is
(a) coal
(b) petroleum
(c) minerals
(d) forest. 

Answer: D

Ques. Which is the cause of damage to relative biological effectiveness?
(a) High temperature
(b) Pollution
(c) Radiation
(d) Low temperature

Answer: B

Ques. Which of the following is a secondary pollutant?
(a) PAN
(b) Aerosol
(c) CO
(d) CO₂ 

Answer: A

Ques. Petroleum is a
(a) synthetic product
(b) renewable resource
(c) nonrenewable resource
(d) inconvenient resource. 

Answer: C

Ques. Minerals and metals are
(a) biodegradable resources
(b) renewable
(c) non-renewable
(d) renewable and non-renewable resources.

Answer: D

Ques. Domestic waste constitutes
(a) non-biodegradable pollution
(b) biodegradable pollution
(c) effluents
(d) air pollution.

Answer: B

Ques. Which one of the following statements is not valid for aerosols?
(a) They alter rainfall and monsoon patterns.
(b) They cause increased agricultural productivity.
(c) They have negative impact on agricultural land.
(d) They are harmful to human health.

Answer: B

Ques. Acid rain is caused by increase in the atmospheric concentration of
(a) CO₂ and CO
(b) O₃ and dust
(c) SO₂ and NO₂
(d) SO₃ and CO. 

Answer: C

Ques. Which of the following are most suitable indicators of SO2 pollution in the environment?
(a) Algae
(b) Fungi
(c) Lichens
(d) Conifers 

Answer: C

Ques. A location with luxuriant growth of lichens on the trees indicates that the
(a) trees are very healthy
(b) trees are heavily infested
(c) location is highly polluted
(d) location is not polluted. 

Answer: D

Ques. A scrubber in the exhaust of a chemical industrial plant removes
(a) gases like sulphur dioxide
(b) particulate matter of the size 5 micrometer or above
(c) gases like ozone and methane
(d) particulate matter of the size 2.5 micrometer or less. 

Answer: A

Ques. The Air Prevention and Control of Pollution Act came into force in
(a) 1985
(b) 1990
(c) 1975
(d) 1981 

Answer: D

Ques. Which one of the following is not correct with regard to the harmful effects of particulate matter of the size 2.5 micrometer or less?
(a) It can cause respiratory problems.
(b) It can directly enter into our circulatory system.
(c) It can cause inflammation and damage to the lungs.
(d) It can be inhaled into the lungs.

Answer: B

Ques. dB is a standard abbreviation used for the quantitative expression of
(a) the density of bacteria in a medium
(b) a particular pollutant
(c) the dominant Bacillus in a culture
(d) a certain pesticide. 

Answer: B

Ques. Steps taken by the Government of India to control air pollution include
(a) compulsory PUC (Pollution under control) certification of petrol driven vehicles which tests for carbon monoxide and hydrocarbons
(b) permission to use only pure diesel with a maximum of 500 ppm sulphur as fuel for vehicles
(c) use of non-polluting compressed natural gas (CNG) only as fuel by all buses and trucks
(d) compulsory mixing of 20% ethyl alcohol with petrol and 20% biodiesel with diesel. 

Answer: A

Ques. According to Central Pollution Control Board (CPCB), which particulate size in diameter (in micrometers) of the air pollutants is responsible for greatest harm to human health?
(a) 1.0 or less
(b) 5.2 - 2.5
(c) 2.5 or less
(d) 1.5 or less 

Answer: C

Ques. In a coal fired power plant electrostatic precipitators are installed to control emission of
(a) NOX
(b) SPM
(c) CO
(d) SO₂. 

Answer: B

Ques. Photochemical smog pollution does not contain
(a) PAN (peroxyacyl nitrate)
(b) ozone
(c) nitrogen dioxide
(d) carbon dioxide. 

Answer: D

Ques. Lead concentration in blood is considered alarming if it is
(a) 20 mg / 100 mL
(b) 30 mg / 100 mL
(c) 4 - 6 mg / 100 mL
(d) 10 mg / 100 mL.

Answer: B

Ques. Fluoride pollution mainly affects
(a) brain
(b) heart
(c) teeth
(d) kidney. 

Answer: C

Ques. What is the intensity of sound in normal conversation?
(a) 10-20 dB
(b) 30-60 dB
(c) 70-90 dB
(d) 120-150 dB 

Answer: B

Very Short Answer Type Questions

Question. Use of lead-free petrol or diesel is recommended to reduce the pollutants emitted by automobiles. What role does lead play?
Answer : Catalytic converters, having expensive metals namely platinum, palladium and rhodium as the catalysts are fitted into automobiles for reducing emission of poisonous gases and to convert unburnt hydrocarbons into CO2 and H.

Question. Name an industry which can cause both air and thermal pollution and as well as eutrophication.

Answer : Chemical fertiliser unit, thermal power plant, refineries, smelting and metallurgical processing units steel mills, and the industries using steam or water as coolant causes both air and thermal pollution. The chemical release form these Industries (if rich in nitrogen and phosphorus) may result in eutrophication.

Question. What is an algal bloom? 
Answer : The extensive growth of planktonic (free-floating) algae in water bodies due to the presence of organic matter in water (cnitrogen and phosphores) that acts as a food source is called an algal bloom. This imparts a distinct colour to the water bodies.

Question. Write the unit used for measuring ozone thickness. 
Answer : Dobson unit.

Question. What is meant by ozone hole?
Answer : Depletion of ozone widely in the stratosphere, particularly over the Antarctic region result in formation of thinned ozone layer called ozone hole.

Question. Write the name of the organism that is referred to as the ‘Terror of Bengal’. 
Answer : Water hyacinth (Eichhornia crassipes).

Question. Name the gas which holds up ultraviolet rays.
Answer : Ozone

Question. In spite of being non-polluting, why are there great apprehensions in using nuclear energy for generating electricity? 
Answer : There are great apprehensions in using nuclear energy because of accidental leakages and finding ways for safe disposal of radioactive waste.

Question. What is an algal bloom? 
Answer : The excessive growth of algae (free-floating) that causes colouration of water bodies is called algal bloom.

Question. It is a common practice to undertake desilting of the overhead water tanks. What is the possible source of silt that gets deposited in the water tanks.
Answer : The soil particles carried by water from the source of supply.

Question. List two advantages of the use of unleaded petrol in automobiles as fuel.
Answer : (i) Allows the catalytic convertor to remain active.
(ii) Reduces air pollution.

Question. Domestic sewage contains certain substances or salts which are difficult to remove. Name any four of them
Answer : Nitrate, phosphate, metal ions and organic compound.

Question. It is a common practice to undertake desilting of the overhead water tanks. What is the possible source of silt that gets deposited in the water tanks? 
Answer : The source of silt that get deposited in overhead water tank are soil particles, which are carried out with water from the source of supply like deep borewell, rivers, etc.

Question. What is cultural eutrophication? 
Answer : The phenomenon wherein effluents from the industries and homes accelerate the natural and cultural ageing process of lakes and other water bodies that normally may take thousands of years is called accelerated eutrophication.

Question. What is reforestation? 
Answer : Reforestation is the process of restoring a forest that had once existed but was removed at some point of time in the past. Though, it can occur naturally in a deforested area but we can expedite it by planting trees with due consideration to biodiversity that earlier existed in that area.

Question. What is the best solution for the treatment of electronic wastes? 
Answer : The best solution for the treatment of electronic wastes is to recycle it. Electronic waste recycling facilities have advanced considerably and now they can be recycled 95-98% by weight. Recycling has two fold benefits
(i) It prevents the toxic components of computers from entering the delicate environment and ground water via landfill.
(ii) It also slows the use and mining of primary raw materials.

Question. List any two adverse effects of particulate matter on human health. 
Answer : The fine particulate (PM of size 2.5 μm or less) can problems cause
(i) Breathing and respiratory
(ii) Irritation
(iii) Inflammations
(iv) Damage to the lungs and premature death

Short Answer Type Questions

Question. Is it true that if the dissolved oxygen level drops to zero, the water will become septic. Give an example which could lower the dissolved oxygen content of an aquatic body. 
Answer : Yes, it is true, in case of zero level of dissolved oxygen (DO), the water becomes septic. Organic pollution like fertiliser in aquatic bodies is responsible for lowering (upto zero) the level of dissolved oxygen.

Question. Name any one green house gas and its possible source of production on a large scale. What are the harmful effects of it? 
Answer : The common green house gases areCO2,CH4, CFC, oxide of nitrogen (N O 2 ), water vapour and O3. The level of CO2 (green house gas) is increasing due to large scale deforestation, change in land use and unlimited buring of fossils fuel and is leading to global warming. The source of methane and other main green house gases are garbage dump, incomplete decomposition by anaerobic methanogens, flooded paddy field and marshy land. About 90-95% of CH4 is produced/generated by rice fields of Asia.

Question. Observe the figure A and B given below and answer the following questions 
(i) The power generation by the above two methods is non-polluting, True/False.
(ii) List any two applications of solar energy
(iii) What is a photovoltaic cell?
Answer : (i) Figure A is solar energy panel and figure B is wind mill device. Both devices produce power without polluting the environment.
(ii) Solar lamp (lantern) (made up of a LED lamp, a photo-voltaic solar panel and rechargeable battery) and solar hot water system (geyser) are the two application of solar energy.
(iii) A solar cell is also called as photovoltaic cell. It is a form of photoelectric cell which converts the light energy into electrical energy by photovoltaic cell.

Question. It is a common practice to plant trees and shrubs near the boundary walls of buildings. What purpose do they serve? 
Answer : A common practice to grow and maintain trees and shrub near the boundary wall of residential, official building acts as a barrier for sound and check noise pollution. This green belt of tree and shrub also acts as an effective measure to check primary air pollutants like dust, flyash, etc.

Question. Why has the National Forest Commission of India recommended a relatively larger forest cover for hills than for plains? 
Answer : It is our moral duty to protect, restore and conserve/preserve forest as they are highly beneficial for mankind In India, around 30% of land was covered by forest in early 20th century, which has been reduced to 18-19% by the year 2000. National Forest Commission of India (1988) recommended a relatively large forest cover (67%) for the hills and 33% for the plains. Recommendation a large forest area for hills is due to its properties like checking soil erosion, percolation and recharging ground water, checking landslide and other natural calamities and to maintain the original flora and fauna of hills.

Long Answer Type Questions

Question. Observe figure and answer the following questions. (Image 288) 
(i) What ecological term is used to describe the DDT accumulation at different trophic levels?
(ii) List any one effect of DDT accumulation on birds.
(iii) Will DDT accumulation lead to eutrophication?
(iv) Does it affect the BOD?
(v) Name disease caused by accumulation of any heavy metal.
Answer : (i) The ecological term used to describe the DDT accumulation at different trophic levels is called biomagnification.
(ii) High concentrations of DDT disturb calcium metabolism in birds, which causes thinning of egg shell and their premature breaking, eventually causing decline in bird populations.
(iii) Yes, DDT accumulation can lead to eutrophication.
(iv) It increases the BOD, resulting in a decrease in dissolved oxygen in the water body.
(v) Eating fish that has accumulated mercury, a heavy metal, causes a disease called Minamata. It is characterised by diarrhoea, haemolysis, numbness, deafness, mental derangement, meningitis and death.

Question. Water logging and soil salinity are some of the problems that have come in the wake of the Green Revolution. Discuss their causes and adverse effects to the environment. 
Answer : Water logging and soil salinity is caused by extensive irrigation without proper drainage of water. Continuous presence of water draws salt to the surface of the soil, which gets deposited as a thin crust on the land surface or start collecting at the roots of the plants.
Adverse effects
(i) Increased salt content stunts the growth of crop plants.
(ii) Root cells saturated with saline water gets damaged.
(iii) Plants die.
(iv) Crop yield gets affected.
(v) Financial loss to the farmers. Although properly managing the soil-water system can correct the salination and water logging, but the economic costs of this are very high.

Question. What are multipurpose trees? Give the botanical and local names of any two multipurpose trees known to you and list their uses. 
Answer : Multipurpose trees are those tree which on plantation fulfills a number of purpose, like shade, providing, soil improvement, provide wood, fruit and food etc. In other words, multipurpose trees serve a wide variety of function and services for human needs. Neem ( Azardicta, indica) is known for its medicinal properties. Its fruit, leaves, wood and oil extracted from wood is used in most of the ayurvedic medicines. Its wood is pest resistant due to chemical azardiction. Another most important tree is coconut palm. Its botanical name is Coccos nucifera and belongs to the family-Palmae, it serves a variety of function. As we get oil, wood and food fibre, from this plant. This plant has fibre, medicinal and commercial importance. Some other multipurpose trees are Moringa oleifera and Gliricidia sepium, which is widely used for fences in central America and provide fire wood fooder and fix atmospheric N2. While M.oleifera is commonly used for animal forage and shade, its leaves are edible.

QUESTIONS

VSA (1 MARK)

Question 1. Why should the velocity of air between the plates of an electrostatic precipitator be low?
Answer: The velocity of air between the plates of an electrostatic precipitator must be kept low to allow sufficient time for the dust particles to fall and get collected on the charged plates.
In simple words: Air speed must be slow so that dust has enough time to settle down.

Exam Tip: Remember the primary function of an electrostatic precipitator in removing particulate matter from thermal power plants.

Question 2. PM2.5 is responsible for causing greatest harm to human health. What is it? How is it harmful?
Answer: PM2.5 refers to particulate matter of size \(2.5\) micrometers or less in diameter. It is harmful to human health because these fine particles can be inhaled deep into the respiratory tract (lungs), causing breathing problems, irritation, inflammation, and premature death.
In simple words: PM2.5 consists of tiny particles that enter deep into our lungs and damage health.

Exam Tip: Always mention both the size dimension (\(2.5\) micrometers) and the site of action (deep lungs) to secure full marks.

Question 3. What is the noise level that can cause permanent impairment of hearing ability of human beings?
Answer: A noise level of 150 dB (decibels) or more can cause permanent impairment of the hearing ability of human beings.
In simple words: Extremely loud sounds of 150 dB or higher can permanently damage hearing.

Question 4. Why was the Montreal Protocol signed?
Answer: The Montreal Protocol was signed to control the emission and use of ozone-depleting substances (such as chlorofluorocarbons - CFCs) in order to protect the ozone layer.
In simple words: It is an international treaty made to stop substances that destroy the ozone layer.

Exam Tip: Mention ozone-depleting substances like CFCs as key keywords.

Question 5. Jhum cultivation has been in practice from earlier days, but its considered more problematic these days. Why?
Answer: Jhum cultivation (slash and burn agriculture) is considered more problematic today because of a growing population and shorter cycle periods, meaning enough time gap is not given for the natural process of recovery of land from the effects of cultivation, leading to deforestation and soil erosion.
In simple words: Due to less land and high population, the land does not get enough time to recover naturally.

Exam Tip: Highlight the lack of adequate recovery time due to increased population pressure.

Question 6. A radiation causes ageing of skin, skin cancer, and inflamation of cornea called snow blindness. It also damages DNA. Name the radiation.
Answer: Ultraviolet-B (UV-B) radiation.
In simple words: UV-B rays coming from sunlight cause skin cancer and eye damage.

Question 7. Landfills are not much a solution for getting rid of solid wastes. Why?
Answer: Landfill sites are getting filled very fast due to the massive generation of garbage in urban areas. Furthermore, there is a serious risk of underground water resources getting polluted due to the seepage of toxic chemicals from landfills.
In simple words: Landfills fill up too quickly and pollute underground water with harmful chemicals.

Exam Tip: State both problems: space exhaustion and groundwater pollution.

Question 8. Electrostatic precipitator can remove over 99% particulate matter present in exhaust from a thermal power plant. How?
Answer: An electrode wire kept at several thousand volts produces a corona that releases electrons. These electrons attach to dust particles, giving them a net negative charge. The charged dust particles are then attracted and collected by grounded collecting plates.
In simple words: High voltage charges the dust particles, and magnet-like grounded plates attract and trap them.

Exam Tip: Use the sequence: high voltage/corona, charging of particles, attraction by grounded plates.

Question 9. Why is a scrubber used? Which spray is used on exhaust gases passing through a scrubber?
Answer: A scrubber is used to remove gases like sulfur dioxide from industrial exhaust. A spray of water or lime is used on the exhaust gases passing through it.
In simple words: Scrubbers clean poisonous gases like sulfur dioxide using water or lime spray.

Exam Tip: Remember both water and lime as neutralizing spray agents.

Question 10. There is a sharp decline in dissolved oxygen downstream from the point of sewage discharge. Why? What are its adverse effects?
Answer: Following the discharge of sewage into a river, microorganisms involved in the biodegradation of organic matter present in the sewage consume a large amount of oxygen. This causes a sharp decline in dissolved oxygen, leading to the mortality of fish and other aquatic creatures.
In simple words: Bacteria use up all the oxygen to break down sewage, causing fish and aquatic life to die.

Exam Tip: Link microbial activity with oxygen consumption and fish mortality.

Question 11. Catalytic converters use expensive metals as catalysts. (a) Name the metals generally used. (b) What precaution should be observed while using catalytic converter.
Answer:
(a) The precious metals generally used as catalysts are platinum, palladium, and rhodium.
(b) Motor vehicles equipped with catalytic converters should use unleaded petrol because lead in petrol inactivates (poisons) the catalysts.
In simple words: They use expensive platinum-group metals, and only unleaded fuel must be used so they do not stop working.

Exam Tip: Always mention why unleaded petrol is necessary (lead deactivates the catalysts).

Question 12. What are e-wastes? Why are they creating more problem in developing countries in comparision to developed countries?
Answer: E-wastes are irreparable computers and other electronic goods. They create more problems in developing countries because recycling in these nations often involves manual participation without proper safety gear, exposing workers to toxic substances, whereas in developed countries, recycling is mechanized and safer.
In simple words: Electronic garbage is recycled manually by poor workers in developing countries, exposing them to dangerous toxins.

Exam Tip: Contrast manual recycling in developing nations with mechanized recycling in developed countries.

Question 13. Water logging and salinity are some of the problems that have come in the wake of Green revolution. How does water logging create problems of salinity?
Answer: Water logging draws underground salt to the surface of the soil. As the water evaporates, the salt is deposited as a thin crust on the land surface or collects at the roots of plants, adversely affecting crop growth.
In simple words: Excess water brings underground salt to the top soil, leaving a harmful salty layer as it dries.

Question 14. What is the relationship between BOD, micro-organisms and amount of bio-degradable matter?
Answer: An increase in the amount of biodegradable organic matter leads to the rapid multiplication of microorganisms to degrade it. Consequently, this increases the Biological Oxygen Demand (BOD) level of the water body.
In simple words: More organic waste leads to more bacteria, which increases BOD (oxygen demand).

Exam Tip: Biodegradable matter is directly proportional to microorganism count and BOD.

SA-I (3 MARKS)

Question 15. Deforestation is creating a lot of problems in the environment. List the consequences of deforestation.
Answer: The major consequences of deforestation are:
1. Enhanced carbon dioxide concentration in the atmosphere (leading to global warming).
2. Loss of biodiversity due to destruction of natural habitats.
3. Soil erosion and loss of topsoil fertility.
4. Desertification of productive land.
5. Disturbed hydrological cycles.
In simple words: Deforestation causes global warming, loss of wildlife, soil erosion, and climate disruption.

Exam Tip: List any 3 to 5 clear points to score full marks in 3-mark questions.

Question 16. Enlist four harmful effects caused to the humans living in areas having polluted air. Suggest two measures to reduce air pollution.
Answer:
Harmful effects on humans:
1. Breathing and respiratory problems.
2. Eye irritation and inflammation.
3. Damage to lung tissues.
4. Premature death.
Measures to reduce air pollution:
1. Reduce emissions from automobile exhausts by using cleaner fuels and catalytic converters.
2. Grow more trees (afforestation) to absorb pollutants.
In simple words: Polluted air damages lungs and causes early death. We can reduce it by planting trees and controlling vehicle smoke.

Exam Tip: Clearly separate harmful effects and control measures under subheadings.

Question 17. People have been actively participating in the efforts for the conservation of forests.
(i) Name the award instituted in respect of Amrita Devi to promote such efforts.
(ii) Name the movement launched to protect the trees by hugging them.
(iii) Name the step Government of India has undertaken in 1980’s to work closely with the local communities for protecting and managing forests.
Answer:
(i) Amrita Devi Bishnoi Wildlife Protection Award.
(ii) Chipko Movement.
(iii) Joint Forest Management (JFM).
In simple words: (i) Amrita Devi Award, (ii) Chipko Movement, (iii) Joint Forest Management.

Exam Tip: Memorize these three classic Indian conservation milestones.

LA (5 MARKS)

Question 18. Pollutant released due to human activities (like effluents from industries and homes) can radically accelerate the ageing process of the water body.
(a) Explain how does this process occurs during natural ageing of lake.
(b) Give the term used for accelerated ageing of water bodies. Also give the term used for the natural ageing of lake.
Answer:
(a) Natural ageing of a lake (Eutrophication): As nutrients enter a water body, aquatic plant and animal life increases. Organic remains are deposited on the lake bottom, causing the lake to grow shallower and warmer. Over centuries, floating plants develop in the marshy areas and gradually transform into land due to the accumulation of silt and organic debris.
(b) The term used for accelerated ageing of water bodies caused by human pollutants is Cultural or Accelerated Eutrophication. The term used for natural ageing is Eutrophication.
In simple words: Lakes naturally fill up with nutrients and plants over time, becoming land. Human pollution speeds this up drastically.

Question 19. In Arcata, the town’s people have created an integrated waste water treatment process within a natural system. A citizen group called FOAM helps in upkeep of this project.
(a) What are the main steps in waste water management done in this way?
(b) ‘Ecosan’ in Kerala and Sri Lanka is also an initiative for water conservation. How?
Answer:
(a) The wastewater treatment in Arcata involves two main stages: conventional sedimentation, filtering, and chlorine treatment, followed by biological treatment where algae, fungi, and bacteria absorb and assimilate pollutants in artificial marshes.
(b) 'Ecosan' stands for ecological sanitation. It is an approach to handling human excreta using dry composting toilets. It is a practical, hygienic, efficient, and cost-effective method of recycling human waste into natural fertilizer, thereby conserving water.
In simple words: Arcata uses natural marsh plants to clean wastewater after primary filtration. Ecosan uses waterless composting toilets to save water and recycle waste.

Exam Tip: Highlight the dual role of artificial wetlands in Arcata and dry composting in Ecosan.

Question 20. What are the contribution of Ahmed Khan in Bangalore and Ramesh Chandra Dagar in Sonipat?
Answer:
- Ahmed Khan (Bangalore): Developed 'polyblend', a fine powder of recycled modified plastic. When mixed with bitumen, polyblend enhances plastic-asphalt roads' life span by a factor of three and dramatically improves water repellent properties.
- Ramesh Chandra Dagar (Sonipat, Haryana): Pioneered integrated organic farming, combining agriculture, bee-keeping, dairy management, water harvesting, and composting in a zero-waste procedure where waste from one process is utilized as nutrient input for another.
In simple words: Ahmed Khan used plastic waste to build durable roads, while Ramesh Chandra Dagar created a zero-waste organic farming system.

Exam Tip: Mention 'polyblend' for Ahmed Khan and 'zero-waste integrated organic farming' for Ramesh Chandra Dagar.