Environment & Ecology Mixed Quiz: Set 27

The correct answer is A, cooling water from power stations. Thermal and nuclear power stations draw large volumes of water to condense steam and return it several degrees warmer, which makes them the single largest source of waste heat in rivers, lakes and coastal waters. Refineries, steel plants, paper mills and distilleries follow. B is wrong because municipal sewage is the chief source of organic and bacterial pollution, raising the biochemical oxygen demand, but it is not discharged hot. C is wrong because agricultural run-off carries nitrate and phosphate and causes eutrophication, a nutrient problem rather than a heat problem. D is wrong because plastic waste is a physical pollutant that chokes and entangles aquatic life and breaks down into microplastics; it adds no heat to the water at all.

The correct answer is B, Earthworm. The earthworm is called the farmer's friend because its work keeps soil fit for crops. As it burrows it loosens the soil and lets air and water reach the roots, and the castings it leaves behind are rich in nitrogen, phosphorus and potash, so the topsoil is steadily renewed. Charles Darwin called earthworms nature's ploughmen for this reason. Farmers use the same habit in vermicomposting, where species such as Eisenia fetida turn cattle dung and crop waste into fine manure within a few weeks. A is wrong because the cockroach is a household pest that spoils food and carries germs. C is wrong because the honey bee is useful as a pollinator and for honey, but the name friend of the farmer is not given to it. D is wrong because the housefly spreads diseases such as typhoid and cholera. Exam tip: earthworm, the farmer's friend and nature's plough, used in vermicompost.

The correct answer is C, the Energy Conservation Act, 2001. The Energy Conservation (Amendment) Act, 2022 inserted the power for the Central Government to specify a Carbon Credit Trading Scheme, which is why the market sits with the Ministry of Power and its Bureau of Energy Efficiency rather than with the environment ministry. A is wrong, and is the commonest trap, because the Environment (Protection) Act, 1986 is an umbrella law for standards, notifications and eco-sensitive zones, not for tradable credits. B is wrong because the Electricity Act, 2003 governs generation, transmission, distribution and tariff regulation; renewable purchase obligations sit there, but carbon credits do not. D is wrong because the Air Act, 1981 created the pollution control boards and deals with local air pollutants such as particulate matter and sulphur dioxide, which are regulated by consent and standards rather than by trading.

The correct answer is D, Ecotone. An ecotone is the transition zone where two different ecosystems meet and mix, such as the belt between a grassland and a forest, an estuary between a river and the sea, or a mangrove strip between land and ocean. It holds species of both neighbouring communities along with a few of its own, so the number of species and their density are often higher in it. This crowding at the edge is called the edge effect, and species found only in such a belt are called edge species. A is wrong because the ecosphere means the whole living world of the earth taken together with its environment. B is wrong because ecoboundary is not a term used in ecology. C is wrong because ecotwin is not an ecological term either. Exam tip: tie ecotone to the edge effect, and keep ecotone, a zone, apart from ecocline, a gradual gradient.

The correct answer is B, cooling tower. A cooling tower releases the heat of used cooling water to the atmosphere by evaporation or by air flow, so that the water leaving the plant is close to the temperature of the receiving river or lake. Cooling ponds, spray ponds and the reuse of waste heat through cogeneration work on the same principle. A is wrong because an electrostatic precipitator removes fine dust and fly ash from flue gas by charging the particles, an air pollution device. C is wrong because a cyclone separator uses the spin of the gas stream to throw out coarse particles, again an air pollution device. D is wrong because a scrubber washes gases such as sulphur dioxide out of a flue stream with a liquid or a slurry of lime.

The correct answer is C, 2000. The Noise Pollution (Regulation and Control) Rules were notified in the year 2000 and they were framed under the Environment (Protection) Act, 1986. These Rules create the four zones, industrial, commercial, residential and silence zone, fix a day limit and a night limit for each, define day as 6 a.m. to 10 p.m. and night as 10 p.m. to 6 a.m., and restrict loudspeakers at night. A is wrong because 1986 is the year of the parent Environment (Protection) Act, which is the enabling law and not the noise rules themselves; this is the commonest trap in the question. B is wrong because 1991 is associated with the Public Liability Insurance Act. D is wrong because 2010 is the year of the National Green Tribunal Act, which created the tribunal that later heard noise cases.

The correct answer is B, the Bureau of Energy Efficiency, a statutory body under the Energy Conservation Act, 2001 and the Ministry of Power, which already ran the Perform, Achieve and Trade scheme and so had the measurement and verification experience the carbon market needs. In the same scheme the Grid Controller of India keeps the registry and the Central Electricity Regulatory Commission regulates trading. A is wrong because the Central Pollution Control Board, under the environment ministry, sets and enforces pollution standards and monitors air and water quality; it issues consents, not credits. C is wrong because the Securities and Exchange Board of India regulates securities markets and the disclosure rules for green debt, not the carbon credit itself. D is wrong because NITI Aayog is a policy think tank with no regulatory or administrative power over a trading scheme.

The correct answer is B, the Kyoto Protocol. Adopted in 1997 at COP3 in Japan and in force from 2005, it set binding emission targets for developed countries and gave them three flexible mechanisms to meet them; the Clean Development Mechanism, under Article 12, let a developed country fund an emission-reduction project in a developing country and claim the saving as Certified Emission Reductions. A is wrong because the Montreal Protocol of 1987 deals with ozone-depleting substances such as chlorofluorocarbons and has no emissions-trading machinery. C is wrong because the Cartagena Protocol, under the Convention on Biological Diversity, governs the transboundary movement of living modified organisms. D is wrong because the Nagoya Protocol, also under that Convention, covers access to genetic resources and the fair sharing of benefits from their use. Only the Kyoto Protocol belongs to the climate treaty family that creates carbon credits.

The correct answer is B, bones. Strontium lies just below calcium in the same group of the periodic table and behaves chemically like it, so strontium-90 taken in through milk, water or food is deposited in bone and in teeth in place of calcium. With a half-life of about twenty-nine years it then irradiates the bone marrow for decades and can cause bone cancer and leukaemia. A is wrong because the thyroid gland is the organ that concentrates iodine-131, which is why potassium iodide tablets are given after a reactor accident. C is wrong because the liver is a general site of storage for several heavy metals and for plutonium, but not the specific target of strontium. D is wrong because the retina is damaged by ultraviolet and by very high doses of radiation generally, and no isotope collects there selectively.

The correct answer is B, lichens. A bare rock offers no soil, almost no water and no shelter, and only an organism that can survive long spells of drying and can hold on to bare stone can settle there. A lichen is exactly that, a partnership of an alga and a fungus in which the fungus grips the rock and holds water while the alga makes food. Lichens also release weak acids that eat into the rock and, with their own dead remains, form the first thin film of soil. Option A is wrong because mosses follow the lichens; they need that first film of soil and more moisture than bare rock can give. Option C is wrong because grasses come later still, after the soil is deep enough to hold roots and water. Option D is wrong because shrubs belong to a late seral stage, shortly before the tree climax. The full xerarch sequence to remember is lichen, moss, herb and grass, shrub and finally forest, and the parallel hydrarch sequence begins with phytoplankton in water.

The correct answer is A, Perform, Achieve and Trade, usually shortened to PAT, a market-based scheme under the National Mission for Enhanced Energy Efficiency. Each designated consumer in an energy-intensive industry such as cement, steel, aluminium, fertiliser or thermal power is given a specific energy consumption target; a plant that beats its target earns ESCerts, and a plant that misses it must buy them, which the power exchanges make possible. B is wrong because UJALA is the scheme that distributed LED bulbs at low cost to households, a direct efficiency programme with no certificates. C is wrong because FAME India subsidises electric and hybrid vehicles and charging infrastructure. D is wrong because Saubhagya was the household electrification scheme that aimed to connect every willing unelectrified home. Only PAT trades certificates, which is why it is treated as the forerunner of India's carbon market.

The correct answer is B, Nitrosomonas. Nitrification happens in two stages, and the first is the oxidation of ammonia to nitrite by chemoautotrophic bacteria of the genera Nitrosomonas and Nitrococcus. Option A is wrong because Nitrobacter performs the second stage, oxidising nitrite further to nitrate, the form in which plants mainly absorb nitrogen; questions often swap the two, so the order Nitrosomonas then Nitrobacter is worth memorising. Option C is wrong because Pseudomonas is a denitrifying bacterium that reduces nitrate back to nitrogen gas and so works in the opposite direction. Option D is wrong because Rhizobium fixes atmospheric nitrogen into ammonia inside root nodules, a step that comes before nitrification begins. The order worth memorising is ammonia to nitrite by Nitrosomonas, then nitrite to nitrate by Nitrobacter, and both of these bacteria are chemoautotrophs that take their energy from the oxidation itself.

The correct answer is B, becquerel. The becquerel, symbol Bq, is the SI unit of activity and equals one disintegration per second. A is wrong because the curie is the older, non-SI unit of the same quantity, defined from the activity of one gram of radium, and one curie equals 3.7 multiplied by ten raised to the power ten becquerel; it is a correct unit of radioactivity but not the SI one, which makes it the strongest distractor here. C is wrong because the roentgen measures exposure, that is the ionisation produced in air, and not the activity of the source. D is wrong because the sievert measures equivalent dose, the biological effect of the radiation absorbed by tissue; the related unit gray measures absorbed dose, with one gray equal to 100 rad and one sievert equal to 100 rem.

The correct answer is C, Water Conservation. Tarun Bharat Sangh works on water conservation, and its base is at Bhikampura in Alwar district of Rajasthan. Led by Rajendra Singh, known as the waterman of India, villagers of the area built and repaired thousands of johads, the traditional earthen check dams that hold rainwater and let it sink into the ground. Wells filled again, fields came back under crops and streams such as the Arvari, dry for years, began to flow, which is why the body is studied as a model of community-led water harvesting. Rajendra Singh received the Ramon Magsaysay Award in 2001 and the Stockholm Water Prize in 2015. A is wrong because women's groups are part of the work but not its field. B is wrong because fighting corruption is not its subject. D is wrong because it is not a tribal youth organisation, and Alwar is not a tribal belt. Exam tip: Tarun Bharat Sangh, Rajendra Singh, johads of Alwar and the revived Arvari river.

The correct answer is C, 2022-23. The Union Budget for that year announced the intention, the Government published a Sovereign Green Bonds framework in 2022, and the Reserve Bank of India auctioned the first tranche on the Government's behalf in January 2023, with the proceeds earmarked for renewable energy, clean transport, energy efficiency, sustainable water management and afforestation. A is wrong because in 2018-19 only Indian companies and public sector undertakings had issued green bonds; the sovereign had not. B is wrong because 2020-21 was dominated by pandemic borrowing and carried no green issue. D is wrong because by 2024-25 sovereign green bonds were already an established part of the borrowing calendar rather than a first. Candidates should separate the corporate green bonds that began much earlier from the sovereign issue of January 2023.

The correct answer is A, Sardar Sarovar. The Narmada Bachao Andolan grew up against the Sardar Sarovar dam on the Narmada.

The movement began in 1985 under Medha Patkar, with Baba Amte and others joining later. It argued that raising the dam's height would submerge villages and forests in Madhya Pradesh, Maharashtra and Gujarat and that the people displaced were not being resettled properly. The protest used fasts, rallies and the courts, and in 1993 it made the World Bank withdraw from the project. The Supreme Court allowed construction to continue in 2000 with conditions on rehabilitation.

Option B, Bhakra Nangal, is on the Sutlej in Himachal Pradesh and Punjab. Option C, Rihand, is in Uttar Pradesh on a tributary of the Son. Option D, Tehri, on the Bhagirathi in Uttarakhand, had its own protest led by Sunderlal Bahuguna, not the Narmada Bachao Andolan.

Exam tip: Narmada Bachao - Medha Patkar, Sardar Sarovar; Chipko and Tehri - Sunderlal Bahuguna.

The correct answer is B, 1986. Reactor number four of the Chernobyl plant, in Ukraine in the then Soviet Union, exploded on 26 April 1986 and scattered radioactive iodine, caesium and strontium over a wide area of Europe. A is wrong because 1979 is the year of the Three Mile Island accident in Pennsylvania in the United States, a partial meltdown with far smaller release. C is wrong because 1995 has no major nuclear accident attached to it; it is placed in the options only as filler. D is wrong because 2011 is the year of the Fukushima Daiichi accident in Japan, which followed the Tohoku earthquake and tsunami of 11 March. Chernobyl and Fukushima are the only two events rated at level 7, the highest, on the International Nuclear Event Scale.

The correct answer is C, 500 GW by 2030, the first of the five Panchamrit commitments placed before COP26 in Glasgow in 2021, the others being half of India's energy requirement from renewables by 2030, a billion tonnes off projected emissions by 2030, a 45 per cent cut in the emission intensity of gross domestic product by 2030 against 2005, and net zero by 2070. A is wrong because 175 GW by 2022 was the earlier renewable energy target announced in 2015, a different and much smaller commitment. B is wrong because 450 GW was the figure India spoke of before Glasgow and is the classic distractor; the Panchamrit raised it. D is wrong because no such thousand-gigawatt pledge was made at Glasgow. Note that the 500 GW target counts all non-fossil capacity, so large hydro and nuclear are included along with solar and wind.

The correct answer is B, about 8 days. Iodine-131 has a half-life of roughly eight days, which is why the danger from it after an accident is intense but short-lived, and why potassium iodide tablets are distributed at once so that the thyroid gland is saturated with ordinary iodine and absorbs less of the radioactive form. A is wrong because eight hours is far too short; an isotope of that life would decay away before it spread beyond the plant. C is wrong because eight months would keep the contamination of milk and vegetables going for years, which is not what is observed after a release. D is wrong because eight years belongs to the long-lived group; it is caesium-137 at about thirty years and strontium-90 at about twenty-nine years that make an area uninhabitable for decades.

The correct answer is B, Geiger-Muller counter. A Geiger-Muller counter contains a gas-filled tube in which an entering ray ionises the gas and sets off a pulse of current, so each pulse counts one particle; a film badge worn by a worker records the total dose instead. A is wrong because an anemometer measures wind speed. C is wrong because a hygrometer measures the humidity of air. D is wrong because an audiometer measures hearing sensitivity and is used to detect noise-induced hearing loss, which makes it a tempting choice in a chapter that also covers noise pollution, but it measures the response of the ear and not radiation. Candidates should link each pollutant to its instrument: decibel meter for noise, thermometer for thermal load and Geiger-Muller counter for radiation.