🌿 Environment & Ecology — Solved PYQs 2013–2026
Chapter-wise · Ecology, Biodiversity, Climate, Pollution, Conservation & Conventions · Click options to check answers · Detailed explanations · UPSC Prelims General Studies Paper I.
Energy flows from the producers (diatoms) to primary consumers (crustaceans) to secondary consumers (herrings): Diatoms → Crustaceans → Herrings.
In decreasing net primary productivity the order is mangroves (very high) → grasslands → lakes → open oceans (low).
A lichen is a symbiotic association of an alga (or cyanobacterium), which photosynthesises, and a fungus, which provides structure and absorbs minerals — enabling it to colonise bare rock.
1. Photosynthesis
2. Respiration
3. Decay of organic matter
4. Volcanic action.
Which of the above add carbon dioxide to the carbon cycle on Earth?
Respiration, decay of organic matter and volcanic action all release CO2 into the carbon cycle (2, 3, 4); photosynthesis removes CO2, so 1 is excluded.
Grazing animals browse tree seedlings before they can establish, keeping the grassland from succeeding to forest.
1. Pollination of some plants could be adversely affected.
2. There could be a drastic increase in the fungal infections of some cultivated plants.
3. It could lead to a fall in the population of some species of wasps, spiders and birds.
Fewer butterflies would hurt pollination and reduce food for their predators like wasps, spiders and birds (1 and 3); butterflies do not control plant fungal infections, so 2 is wrong.
Biorock (mineral accretion) technology passes a low current through submerged steel to precipitate limestone, accelerating coral growth for reef restoration.
The Miyawaki method plants native species densely to grow fast, self-sustaining mini-forests, often on small urban plots.
1. Fern
2. Lichen
3. Moss
4. Mushroom
Lichens and mosses are pioneer species that can grow directly on bare rock and other soil-less surfaces; ferns and mushrooms need soil/organic substrate.
1. High clouds primarily reflect solar radiation and cool the surface of the Earth.
2. Low clouds have a high absorption of infrared radiation emanating from the Earth's surface and thus cause a warming effect.
Which of the statements given above is/are correct?
Per the official key, statement 1 is taken as correct; low, thick clouds mainly reflect incoming solar radiation and cool the surface rather than warming it, so statement 2 is wrong.
I. Rain forests produce more oxygen than that produced by oceans.
II. Marine phytoplankton and photosynthetic bacteria produce about 50% of the world's oxygen.
III. Well-oxygenated surface water contains several folds higher oxygen than that in atmospheric air.
Which of the statements given above is/are correct?
Oceans (via phytoplankton and photosynthetic bacteria) produce about half the world's oxygen — more than rainforests (so I is wrong and II is right); water holds far less dissolved oxygen than air, so III is wrong.
Statement I: Underground coal gasification (UCG) converts coal into syngas without mining the coal.
Statement II: Syngas produced from coal gasification consists mainly of hydrogen and carbon monoxide.
Which one of the following is correct?
Both are correct — UCG turns an unmined coal seam into syngas in situ, and syngas is mainly hydrogen and carbon monoxide — but the composition of syngas (II) does not explain the UCG process (I).
Biosphere reserves are designed with core, buffer and transition zones so that biodiversity conservation can coexist with the traditional life and livelihoods of local people.
1. Oak
2. Rhododendron
3. Sandalwood
Oak and rhododendron grow naturally in the Himalayas; sandalwood is a tree of the peninsular (southern) dry forests, so it is excluded.
Which one of the following statements is correct in this context?
Guar gum from cluster-bean seeds is used as a thickening agent in the hydraulic-fracturing fluid used to extract shale gas, which is why demand for it rose sharply.
1. Neem oil can be used as a pesticide to control the proliferation of some species of insects and mites.
2. Neem seeds are used in the manufacture of biofuels and hospital detergents.
3. Neem oil has applications in the pharmaceutical industry.
Which of the statements given above is/are correct?
Neem oil is a well-known bio-pesticide and has pharmaceutical uses (1 and 3); the claim about biofuels and hospital detergents (statement 2) is not correct.
The tall, orange-pulped wild banana (Musa indandamanensis) was discovered in the Andaman Islands.
1. Most of the world's coral reefs are in tropical waters.
2. More than one-third of the world's coral reefs are located in the territories of Australia, Indonesia and the Philippines.
3. Coral reefs host far more number of animal phyla than those hosted by tropical rainforests.
Which of the statements given above is/are correct?
All three are correct: most reefs lie in tropical waters, over a third are in Australian, Indonesian and Philippine waters, and reefs host a greater diversity of animal phyla than tropical rainforests.
1. Cnidaria
2. Fungi
3. Protozoa
All three include symbiotic species — corals (Cnidaria) with zooxanthellae, fungi in lichens and mycorrhizae, and gut protozoa in termites.
Tobacco, cocoa and rubber were all domesticated in the Americas (the New World) and later spread to the Old World.
The Himalayan nettle yields a strong natural textile fibre traditionally woven into cloth in the hills.
1. Andaman and Nicobar Islands
2. Gulf of Kachchh
3. Gulf of Mannar
4. Sunderbans
Coral reefs occur off the Andaman & Nicobar Islands, in the Gulf of Kachchh and in the Gulf of Mannar; the Sunderbans is a muddy mangrove delta unsuitable for coral.
Lemon grass yields citronella-type oil that is widely used as a natural mosquito repellent.
1. NBA checks biopiracy and protects indigenous and traditional genetic resources.
2. NBA directly monitors and supervises scientific research on genetic modification of crop plants.
3. Application for Intellectual Property Rights related to genetic/biological resources cannot be made without the approval of NBA.
The NBA checks biopiracy and its approval is needed for IPRs on Indian biological resources (1 and 3); GM-crop research is overseen by the GEAC, not the NBA, so 2 is wrong.
1. It is a fungus.
2. It grows in some Himalayan forest areas.
3. It is commercially cultivated in the Himalayan foothills of north-eastern India.
Which of the statements given above is/are correct?
Gucchi (morel mushroom) is a wild fungus of Himalayan forests (1 and 2); it is foraged from the wild, not commercially cultivated, so statement 3 is wrong.
1. Jackfruit (Artocarpus heterophyllus)
2. Mahua (Madhuca indica)
3. Teak (Tectona grandis).
How many of the above are deciduous trees?
Mahua and teak are deciduous (they shed their leaves seasonally); jackfruit is evergreen — so only two are deciduous.
Sathyamangalam Tiger Reserve (Tamil Nadu) acts as an ecological corridor connecting the Eastern and Western Ghats, allowing wildlife movement and gene flow.
1. Cashew
2. Papaya
3. Red sanders.
How many of the above trees are actually native to India?
Only red sanders is native to India (Eastern Ghats); cashew and papaya were introduced from the Americas by the Portuguese.
The ecological hierarchy runs organism → population → community → ecosystem → biome → biosphere, from the individual up to the entire zone of life on Earth.
I. Cassava : Woody shrub
II. Ginger : Herb with pseudostem
III. Malabar spinach : Herbaceous climber IV. Mint : Annual shrub V. Papaya : Woody shrub.
How many of the above pairs are correctly matched?
Cassava (woody shrub), ginger (herb with pseudostem) and Malabar spinach (herbaceous climber) are correctly matched; mint is a perennial herb (not an annual shrub) and papaya is a large herb (not a woody shrub) — so only three match.
I. Papaya
II. Pineapple
III. Guava.
How many of the above were introduced in India by the Portuguese in the sixteenth and seventeenth centuries?
Papaya, pineapple and guava are all New-World fruits brought to India by the Portuguese in the 16th–17th centuries.
1. The terrestrial biosphere tends towards a net carbon source.
2. Widespread coral mortality will occur.
Which of the statements given above is/are correct?
Beyond about 2°C of warming, forests and soils can flip from carbon sinks to net carbon sources, and reefs suffer widespread coral mortality — so both statements are correct.
The BioCarbon Fund Initiative for Sustainable Forest Landscapes is a World Bank-managed fund that promotes reduced deforestation and sustainable land use.
'Momentum for Change: Lighthouse Activities' is a UNFCCC Secretariat initiative that showcases successful climate-action projects.
1. Abandoned and uneconomic coal seams
2. Depleted oil and gas reservoirs
3. Subterranean deep saline formations
All three geological formations — unmineable coal seams, depleted oil and gas reservoirs, and deep saline aquifers — can store injected CO2.
1. Climate and Clean Air Coalition (CCAC) to Reduce Short-Lived Climate Pollutants is a unique initiative of the G20 group of countries.
2. The CCAC focuses on methane, black carbon and hydrofluorocarbons.
Which of the statements given above is/are correct?
The CCAC is an open global partnership (not a G20 initiative), so 1 is wrong; it does target short-lived climate pollutants like methane, black carbon and HFCs, so 2 is correct.
I. It establishes a framework for international carbon markets allowing countries to trade emission reductions.
II. Article 6.4 creates a UN-supervised carbon credit mechanism, similar to the Clean Development Mechanism under the Kyoto Protocol.
III. 'Corresponding adjustments' are required to prevent double counting of emission reductions.
Which of the statements given above is/are correct?
All three are correct: Article 6 frames international carbon markets, Article 6.4 sets up a UN-supervised mechanism like the CDM, and 'corresponding adjustments' stop the same reduction being counted twice.
Statement I: Circular economy reduces the emissions of greenhouse gases.
Statement II: Circular economy reduces the use of raw materials as inputs.
Statement III: Circular economy reduces wastage in the production process.
Which one of the following is correct?
All three are correct: by reusing and recycling materials, a circular economy cuts virgin-material use, reduces waste and lowers the greenhouse-gas emissions tied to extraction and processing.
I. Carbon dioxide (CO2) emissions in India are less than 0.5 t CO2/capita.
II. In terms of CO2 emissions from fuel combustion, India ranks second in the Asia-Pacific region.
III. Electricity and heat producers are the largest sources of CO2 emissions in India.
Which of the statements given above is/are correct?
India ranks second in the Asia-Pacific region (after China) for CO2 from fuel combustion, and electricity/heat producers are its largest source (II and III correct); India's per-capita CO2 is about 1.9–2 t, not below 0.5 t, so I is wrong.
Which of the following statements best reflect(s) the implication of this report?
I. Peninsular India will most likely suffer from flooding, tropical cyclones and droughts.
II. The human body cannot cool itself when wet-bulb temperature exceeds 35°C, making outdoor survival impossible.
III. Such heat conditions would primarily affect coastal cities due to sea breeze moderation.
Above a 35°C wet-bulb temperature, sweat cannot evaporate and the body can no longer cool itself, making prolonged outdoor exposure deadly (II correct); inland areas are more vulnerable than coasts, and I/III do not capture the wet-bulb implication.
Statement I: Studies indicate that CO2 emissions from the cement industry account for more than 5% of global carbon emissions.
Statement II: Silica-bearing clay is mixed with limestone while manufacturing cement.
Statement III: Limestone is converted into lime during clinker production for cement manufacturing.
Which one of the following is correct?
All three are correct: cement makes up roughly 7–8% of global CO2, its raw mix is limestone plus silica-bearing clay, and in the kiln limestone (CaCO3) calcines to lime (CaO) releasing CO2.
I. India's Long-Term Low Emission Development Strategy (LT-LEDS) is a crucial tool for achieving net-zero emissions by
2070.
II. India's 4th Biennial Update Report (BUR-4), submitted in December 2024, recorded around 8% decrease in greenhouse gas emissions in 2020 over
2019.
III. Climate-resilient development necessarily depends on quick and short-term achievement of emission reduction targets. Which relationships among the above are correct?
1. Statement I is empirically supported by Statement II.
2. Statement III contradicts the approach implicit in Statement I.
3. Statements I and III together establish the premise of long-term sustainability.
Statement II's reported emission decline supports the LT-LEDS narrative in I, and the short-termism of III contradicts the long-term approach of I (relationships 1 and 2); I and III do not together establish long-term sustainability, so 3 is wrong.
1. It is decarbonized hydrogen obtained from natural gas reforming combined with carbon capture and storage (CCS).
2. It is produced using electrolysis of water with electricity generated by renewable energy.
3. The National Green Hydrogen Mission of India aims for abatement of nearly 50 MMT of annual greenhouse gas emissions by 2030.
Green hydrogen is made by electrolysing water using renewable electricity, and the National Green Hydrogen Mission targets roughly 50 MMT of annual GHG abatement by 2030 (2 and 3); hydrogen from natural gas with CCS is 'blue' hydrogen, not green, so statement 1 is wrong.
Photochemical smog forms when nitrogen oxides and volatile organic compounds react in sunlight to produce ozone (O3) and peroxyacetyl nitrate (PAN).
1. Beryllium
2. Cadmium
3. Chromium
4. Heptachlor
5. Mercury
6. Lead
7. Plutonium
E-waste releases beryllium, cadmium, chromium, mercury and lead (1, 2, 3, 5, 6); heptachlor is a pesticide and plutonium is a nuclear material — neither comes from computers.
Acid rain results from oxides of nitrogen and sulphur dioxide, which form nitric and sulphuric acids in the atmosphere.
1. Arsenic
2. Sorbitol
3. Fluoride
4. Formaldehyde
5. Uranium
Arsenic, fluoride and uranium are known groundwater contaminants in parts of India (1, 3, 5); sorbitol and formaldehyde are not typical drinking-water pollutants.
1. Oxides of sulphur
2. Oxides of nitrogen
3. Carbon monoxide
4. Carbon dioxide
Steel making releases all four — oxides of sulphur and nitrogen, carbon monoxide (ore reduction) and carbon dioxide.
1. They are highly resistant to degradation in the environment.
2. They are able to accumulate in humans and animals.
Both concerns are valid — brominated flame retardants are persistent (resist degradation) and bioaccumulate in humans and animals.
1. They can accumulate in the environment and contaminate water and soil.
2. They can enter the food chains.
3. They can trigger the production of free radicals.
All three concerns are valid — nanoparticles can contaminate soil and water, enter food chains, and generate harmful free radicals in living tissue.
1. The decomposition of human waste in the bio-toilets is initiated by a fungal inoculum.
2. Ammonia and water vapour are the only end products in this decomposition which are released into the atmosphere.
Which of the statements given above is/are correct?
Neither is correct — the decomposition is initiated by an anaerobic bacterial (not fungal) inoculum, and the end products include methane and carbon dioxide, not merely ammonia and water vapour.
1. Fly ash can be used in the production of bricks for building construction.
2. Fly ash can be used as a replacement for some of the Portland cement content of concrete.
3. Fly ash is made up of silicon dioxide and calcium oxide only, and does not contain any toxic elements.
Fly ash is used to make bricks and to partly replace cement in concrete (1 and 2); it also contains toxic trace elements, so statement 3 is wrong.
1. Carbon dioxide
2. Carbon monoxide
3. Nitrogen dioxide
4. Sulphur dioxide
5. Methane
The Air Quality Index uses carbon monoxide, nitrogen dioxide and sulphur dioxide (along with PM, ozone, ammonia and lead); carbon dioxide and methane are not AQI pollutants.
1. It is a technique for cleaning up pollution by enhancing the same biodegradation process that occurs in nature.
2. Any contaminant with heavy metals such as cadmium and lead can be readily and completely treated by bioremediation using microorganisms.
3. Genetic engineering can be used to create microorganisms specifically designed for bioremediation.
Bioremediation accelerates natural biodegradation and can use genetically engineered microbes (1 and 3); heavy metals cannot be fully degraded by microbes, so statement 2 is wrong.
BOD measures the oxygen consumed by microbes decomposing organic matter in water; a high BOD indicates heavy organic pollution.
The UNEP-supported Common Carbon Metric is a standard for measuring and reporting the carbon footprint of building operations worldwide.
Microbeads are tiny plastic particles that pass through water treatment and harm marine ecosystems as microplastic pollution.
These four are highly toxic pesticides (insecticides) used in agriculture, raising health and environmental concerns.
1. State the requirement of public participation in the process of environmental protection, and the procedure and manner in which it is sought.
2. Lay down the standards for emission or discharge of environmental pollutants from various sources.
Which of the statements given above is/are correct?
The EPA 1986 empowers the government to set emission/discharge standards (statement 2); it does not lay down a requirement for public participation in the manner described, so statement 1 is wrong.
The Solid Waste Management Rules, 2016 lay down detailed criteria for identifying landfill and waste-processing sites; waste is segregated into three (not five) streams and the Rules have a wider applicability.
Extended Producer Responsibility (EPR) — making producers responsible for end-of-life products — was first introduced in India through the e-Waste (Management and Handling) Rules, 2011.
1. Automobile exhaust
2. Tobacco smoke
3. Wood burning
4. Using varnished wooden furniture
5. Using products made of polyurethane
Automobile exhaust, tobacco smoke, wood burning and varnished furniture all expose people to benzene (1–4); polyurethane products do not release benzene, so 5 is excluded.
1. Coal ash contains arsenic, lead and mercury.
2. Coal-fired power plants release sulphur dioxide and oxides of nitrogen into the environment.
3. High ash content is observed in Indian coal.
Which of the statements given above is/are correct?
All three are correct — coal ash carries toxic metals, coal plants emit SO2 and NOx, and Indian coal is notably high in ash content.
1. Construction of base road
2. Improvement of agricultural soil
3. Production of cement
Steel slag is reused in all three ways — as road-base material, as a soil conditioner/liming agent, and as a raw input in cement production.
The R2 (Responsible Recycling) standard certifies environmentally responsible practices in the electronics/e-waste recycling industry.
1. They may release lethal quantities of carbon monoxide into the environment.
2. The copper slag can cause the leaching of some heavy metals into the environment.
3. They may release sulphur dioxide as a pollutant.
All three are valid concerns: copper smelting can release carbon monoxide and sulphur dioxide, and its slag can leach heavy metals into soil and water.
1. Brakes of motor vehicles
2. Engines of motor vehicles
3. Microwave stoves within homes
4. Power plants
5. Telephone lines
Magnetite nanoparticles come from vehicle brakes, vehicle engines and power plants (1, 2, 4); microwave stoves and telephone lines are not sources.
1. It is a product of oil refineries.
2. Some industries use it to generate power.
3. Its use causes sulphur emissions into the environment.
Which of the statements given above are correct?
All three are correct — furnace oil is a refinery product, is burnt by some industries for power, and releases sulphur emissions.
The Central Ground Water Authority is constituted under the EPA, 1986; the NGT, NBA and WCCB are created under their own separate statutes.
1. Carbon monoxide
2. Nitrogen oxide
3. Ozone
4. Sulphur dioxide. Excess of which of the above in the environment is/are the cause(s) of acid rain?
Acid rain is caused mainly by oxides of nitrogen and sulphur dioxide, which form nitric and sulphuric acids in the atmosphere.
1. The 24-hour mean of PM2.5 should not exceed 15 µg/m³ and the annual mean of PM2.5 should not exceed 5 µg/m³.
2. In a year, the highest levels of ozone pollution occur during periods of inclement weather.
3. PM10 can penetrate the lung barrier and enter the bloodstream.
4. Excessive ozone in the air can trigger asthma.
Which of the statements given above are correct?
The WHO 2021 PM2.5 limits and ozone's asthma trigger are correct (1 and 4); ozone peaks in hot sunny (not inclement) weather, and it is fine PM2.5 (not PM10) that enters the bloodstream, so 2 and 3 are wrong.
1. Other than those made by humans, nanoparticles do not exist in nature.
2. Nanoparticles of some metallic oxides are used in the manufacture of some cosmetics.
3. Nanoparticles of some commercial products which enter the environment are unsafe for humans.
Which of the statements given above is/are correct?
Metallic-oxide nanoparticles are used in cosmetics and some released nanoparticles are unsafe (2 and 3); nanoparticles also occur naturally (volcanic ash, sea spray), so statement 1 is wrong.
1. Biofilters provide waste treatment by removing uneaten fish feed.
2. Biofilters convert ammonia present in fish waste to nitrate.
3. Biofilters increase phosphorus as a nutrient for fish in water.
How many of the statements given above are correct?
Per the official key, two statements are correct — biofilters help treat waste and convert toxic ammonia to nitrate; they do not add phosphorus as a fish nutrient, so statement 3 is wrong.
1. Gold mining activity is a source of mercury pollution in the world.
2. Coal-based thermal power plants cause mercury pollution.
3. There is no known safe level of exposure to mercury.
How many of the above statements are correct?
Per the official key, two statements are correct — artisanal gold mining and coal-fired power plants are both major mercury sources.
Coal-burning power plants are the single largest source of SO2 emissions, since coal contains sulphur that oxidises to SO2 on combustion.
Greenwashing is misleading marketing that makes a product or company appear more environmentally friendly than it really is.
Statement-I: Many chewing gums found in the market are considered a source of environmental pollution.
Statement-II: Many chewing gums contain plastic as gum base.
Which one of the following is correct in respect of the above statements?
Both statements are correct and II explains I — many chewing gums use a plastic (polymer) gum base, which is exactly why the discarded gum becomes an environmental pollutant.
1. PFAS are found to be widespread in drinking water, food and food packaging materials.
2. PFAS are not easily degraded in the environment.
3. Persistent exposure to PFAS can lead to bioaccumulation in animal bodies.
Which of the statements given above are correct?
All three are correct — PFAS ('forever chemicals') are widespread in water, food and packaging, resist environmental degradation, and bioaccumulate in animals.
Membrane bioreactors combine biological treatment with membrane filtration and are used in advanced wastewater treatment.
Statement I: Activated carbon is a good and attractive tool to remove pollutants from effluent streams and to remediate contaminants from various industries.
Statement II: Activated carbon exhibits a large surface area and a strong potential for adsorbing heavy metals.
Statement III: Activated carbon can be easily synthesized from environmental wastes with high carbon content.
Which one of the following is correct?
All three are correct: activated carbon's huge surface area makes it excellent at adsorbing pollutants and heavy metals, and it can be made from carbon-rich wastes such as coconut shells.
1. Silver iodide
2. Potassium iodide
3. Liquid nitrogen
Silver iodide and potassium iodide act as ice-nucleating agents in cloud seeding; liquid nitrogen is not used as a seeding agent.
I. Cigarette butts
II. Eyeglass lenses
III. Car tyres.
How many of them contain plastic?
All three contain plastics — cigarette filters are cellulose-acetate plastic, eyeglass lenses are typically polycarbonate, and tyres contain synthetic-rubber polymers.
Keibul Lamjao (Manipur) is the world's only floating national park, formed of 'phumdis' on Loktak Lake and the last natural home of the sangai deer.
Pakhui (Pakke) Wildlife Sanctuary and Tiger Reserve lies in the East Kameng district of Arunachal Pradesh.
The Agasthyamala Biosphere Reserve in the southern Western Ghats includes the Neyyar, Peppara and Shendurney sanctuaries and the Kalakad-Mundanthurai Tiger Reserve.
1. Gharial
2. Indian Wild Ass
3. Wild Buffalo
All three — gharial, Indian wild ass and wild buffalo — are Schedule I animals, so hunting them is prohibited except under special legal provisions.
1. Once the Central Government notifies an area as a 'Community Reserve', the Chief Wildlife Warden of the State becomes the governing authority of such forest.
2. 'Community Reserve' is a type of 'Protected Area' that gives more decision-making power to local communities compared to a 'National Park'.
Community Reserves give local communities the most say among protected-area types (2 correct); they are notified by State governments and managed by a community committee, not the Chief Wildlife Warden, so 1 is wrong.
1. Wild animals are the sole property of the government.
2. When a wild animal is declared protected, such animal is entitled to equal protection whether it is found in protected areas or outside.
3. Apprehension of a protected wild animal becoming a danger to human life is sufficient ground for its capture or killing.
A protected animal is equally protected inside or outside protected areas (2 correct); animals are not the 'sole' property of government, and mere apprehension of danger is not by itself sufficient ground to kill — so 1 and 3 are wrong.
Nagarjunasagar-Srisailam (Andhra Pradesh/Telangana) is India's largest tiger reserve and therefore has the largest Critical Tiger Habitat (core zone).
The National Chambal Sanctuary, along the Chambal River, holds the largest wild population of the critically endangered gharial.
1. It was declared a Tiger Reserve in India in
2025. 2. Sakhya Sagar, which is designated as a Ramsar Site, is situated within this National Park.
3. Its area is shared between Madhya Pradesh and Rajasthan.
Madhav National Park (Shivpuri, Madhya Pradesh) was notified as a Tiger Reserve in 2025 and the Ramsar-listed Sakhya Sagar lies within it (1 and 2 correct); it lies wholly in Madhya Pradesh, not shared with Rajasthan, so 3 is wrong.
1. 'Ecosystem Survey and Analysis' is a vertical under this platform, the lead institute of which is the Botanical Survey of India, Kolkata.
2. 'Research and Management of Ecosystem Service' is a vertical, the lead institute of which is the Central Zoo Authority, New Delhi.
3. 'Capacity Development Support' is a vertical, the lead institute of which is the Indian Institute of Forest Management, Bhopal.
The Ecosystem Survey and Analysis vertical (led by the Botanical Survey of India) and the Capacity Development Support vertical (led by IIFM, Bhopal) are correctly matched (1 and 3); the ecosystem-service research vertical is not led by the Central Zoo Authority, so 2 is wrong.
The Nagoya Protocol, under the Convention on Biological Diversity, governs access to genetic resources and the fair and equitable sharing of benefits (ABS) arising from their use.
1. It aims to promote effective action through innovative national programmes and supportive international partnerships.
2. It has a special/particular focus on South Asian and North African regions.
3. Its Secretariat facilitates the allocation of a major portion of financial resources to affected countries.
The UNCCD promotes action through national programmes and international partnerships (statement 1); it focuses especially on Africa (not South Asia/North Africa) and its Secretariat does not allocate the bulk of finances, so 2 and 3 are wrong.
Agenda 21 is the action plan on sustainable development adopted at the 1992 Rio Earth Summit (UNCED).
1. It serves as a financial mechanism for the Convention on Biological Diversity and the UNFCCC.
2. It undertakes scientific research on environmental issues at the global level.
The GEF is the financial mechanism for the CBD, UNFCCC, UNCCD and other conventions (statement 1 correct); it funds projects but does not itself undertake scientific research, so statement 2 is wrong.
1. The International Treaty on Plant Genetic Resources for Food and Agriculture
2. The United Nations Convention to Combat Desertification
3. The United Nations Framework Convention on Climate Change.
Which of the above are legally binding agreements?
All three are legally binding treaties — the Plant Treaty, the UNCCD and the UNFCCC.
1. IUCN is an organ of the United Nations and CITES is an international agreement between governments.
2. IUCN runs thousands of field projects around the world to better manage natural environments.
3. CITES is legally binding on the States that have joined it, but this Convention does not take the place of national laws.
IUCN runs many field projects and CITES is binding on parties while still needing national laws (2 and 3); IUCN is an independent union, not a UN organ, so 1 is wrong.
The Climate Action Tracker is an independent scientific analysis produced by a coalition of research organisations, not a UN or IPCC body.
1. It is an initiative of UNEP and UNESCO.
2. It is a movement in which the participants switch off the lights for one hour on a certain day every year.
3. It is a movement to raise awareness about climate change and the need to save the planet.
Which of the statements given above is/are correct?
Earth Hour is a WWF initiative (not UNEP/UNESCO) in which people switch off lights for one hour to raise awareness about climate change — so 2 and 3 are correct.
1. TRAFFIC is a bureau under the United Nations Environment Programme (UNEP).
2. The mission of TRAFFIC is to ensure that trade in wild plants and animals is not a threat to the conservation of nature.
Which of the above statements is/are correct?
TRAFFIC is a wildlife-trade monitoring network run jointly by WWF and IUCN, not a UNEP bureau (so 1 is wrong); statement 2 correctly states its mission.
The Nature Restoration Law, adopted in 2024, is EU legislation setting binding targets to restore degraded ecosystems across the Union.
The Kunming-Montreal GBF's flagship '30×30' target commits parties to conserve at least 30% of land and 30% of oceans by 2030.
The Khasi Hills Community REDD+ project in Meghalaya was India's first community-led, Plan Vivo-certified REDD+ project.
1. It is an intergovernmental organisation.
2. It works at the field level to develop and mobilise knowledge and use the best practices to protect wetlands.
Wetlands International is a global non-governmental (not intergovernmental) organisation that works at the field level to conserve and restore wetlands — so only statement 2 is correct.
1. Reduction in weed infestation
2. Reduction in soil salinity
3. Absence of seepage loss of water
Drip irrigation reduces weeds (only the root zone is wetted) and limits salinity build-up (1 and 2); it reduces but does not eliminate seepage, so the word 'absence' makes 3 wrong.
1. Under the Ramsar Convention, it is mandatory on the part of the Government of India to protect and conserve all the wetlands in the territory of India.
2. The Wetlands (Conservation and Management) Rules, 2010 were framed by the Government of India based on the recommendations of the Ramsar Convention.
3. The Wetlands (Conservation and Management) Rules, 2010 also encompass the drainage area or catchment regions of the wetlands as determined by the authority.
Only statement 3 is correct — the Rules cover the catchment area; Ramsar does not require protecting every wetland, and the 2010 Rules were framed under the Environment (Protection) Act, not on Ramsar's recommendation.
1. Part of the water needs of urban areas will be met through recycling of waste-water.
2. The water requirements of coastal cities with inadequate alternative sources of water will be met by adopting appropriate technologies that allow the use of ocean water.
3. All the rivers of Himalayan origin will be linked to the rivers of Peninsular India.
The National Water Mission promotes wastewater recycling and desalination for water-scarce cities (1 and 2); river interlinking is a separate programme, so 3 is wrong.
Which one of the following functions of wetlands best reflects the above statement?
Like kidneys filter blood, wetlands filter sediments and pollutants and purify water before it moves on — the function the analogy captures.
The Montreux Record lists Ramsar sites where the ecological character has changed, is changing or is likely to change due to human interference.
1. Mangroves reduce tidal energy and store freshwater, making them ideal sites for paddy cultivation in saline estuarine belts.
2. Their salt-sensitive roots filter seawater, making mangroves key to converting coastal land into freshwater aquaculture zones.
3. By withstanding tidal surges and offering biomass resources, mangroves function both as natural bio-shields and livelihood bases for rural communities.
Mangroves buffer coasts against tidal surges and provide biomass and livelihoods, acting as natural bio-shields (statement 3); they are salt-tolerant coastal forests, not tools for paddy or freshwater aquaculture, so 1 and 2 are wrong.
1. Star tortoise
2. Monitor lizard
3. Pygmy hog
4. Spider monkey.
Which of the above are naturally found in India?
The star tortoise, monitor lizard and pygmy hog are native to India; the spider monkey is found in the rainforests of Central and South America, so it is excluded.
1. Gharial
2. Leatherback turtle
3. Swamp deer. Which among the above is/are endangered?
The gharial, the leatherback turtle and the swamp deer (barasingha) are all threatened/endangered species.
1. Tamil Nadu
2. Kerala
3. Karnataka
4. Andhra Pradesh
The lion-tailed macaque is endemic to the Western Ghats and is found in Tamil Nadu, Kerala and Karnataka, but not in Andhra Pradesh.
1. Construction of dams and barrages on rivers
2. Increase in the population of crocodiles in rivers
3. Getting trapped in fishing nets accidentally
4. Use of synthetic fertilizers and other agricultural chemicals in crop-fields in the vicinity of rivers
Dams/barrages, accidental entanglement in fishing nets and agro-chemical pollution all threaten river dolphins (1, 3, 4); a rise in crocodile numbers is not a recognised cause, so 2 is excluded.
Which one of the following is/are such bird/birds?
1. Painted Stork
2. Common Myna
3. Black-necked Crane
Among these, only the common myna habitually follows grazing cattle to catch the insects they flush out; the painted stork and black-necked crane are wetland birds.
1. It is a herbivorous marine animal.
2. It is found along the entire coast of India.
3. It is given legal protection under Schedule I of the Wildlife (Protection) Act.
The dugong is a herbivorous 'sea cow' protected under Schedule I (1 and 3); it is restricted to seagrass areas like the Gulf of Mannar, Palk Bay, Gulf of Kutch and the Andamans, not the entire coast, so 2 is wrong.
The Gangetic river dolphin (Susu) was declared India's National Aquatic Animal in 2009; it is nearly blind and navigates by echolocation.
1. It is a tree species found in a part of South India.
2. It is one of the most important trees in the tropical rain forest areas of South India.
Which of the statements given above is/are correct?
Red Sanders is a South Indian tree (statement 1 correct), but it grows in the dry deciduous forests of the Eastern Ghats (Andhra Pradesh), not in tropical rain forests, so statement 2 is wrong.
1. It is capable of swimming up to three kilometres in seawater.
2. It survives by grazing on mangroves.
3. It lives in the wild and cannot be domesticated.
The Kharai camel of Kutch can swim several kilometres in seawater to graze on mangroves (1 and 2); it is a domesticated breed, so statement 3 is wrong.
The Great Indian Hornbill inhabits the tall evergreen forests of the Western Ghats (and the north-east).
1. Asiatic lion is naturally found in India only.
2. Double-humped camel is naturally found in India only.
3. One-horned rhinoceros is naturally found in India only.
Which of the above is/are correct?
The Asiatic lion (Gir) and the Indian one-horned rhino occur naturally only in the Indian subcontinent (1 and 3); the double-humped Bactrian camel is native to Central Asia, so 2 is wrong.
Prosopis juliflora is an invasive alien tree whose aggressive, thorny spread in grazing lands crowds out native plants and cuts the pasture available to livestock.
1. Blue-finned Mahseer : Cauvery River
2. Irrawaddy Dolphin : Chambal River
3. Rusty-spotted Cat : Eastern Ghats.
Which of the pairs given above are correctly matched?
The blue-finned mahseer (Cauvery) and the rusty-spotted cat (Eastern Ghats) are correctly matched (1 and 3); the Irrawaddy dolphin is found in Chilika Lake, not the Chambal, so 2 is wrong.
1. Musk Deer : Greater Himalayas and Trans-Himalayan region
2. Snow Leopard : Siachen Glacier region only
3. Hump-backed Mahseer : Cauvery River.
Which of the pairs given above is/are correctly matched?
Musk deer (Greater/Trans-Himalaya) and the hump-backed mahseer (Cauvery) are correctly matched (1 and 3); the snow leopard ranges across many Himalayan states, not Siachen only, so 2 is wrong.
1. A plant species found in Mediterranean scrub ecosystems
2. A group of flowering plants resembling stones
3. Bioluminescent fungi found in the Western Ghats
Lithops ('living stones') are southern-African succulent flowering plants that mimic pebbles as camouflage — only statement 2 is correct.
1. The leader of an elephant group is a female.
2. The maximum gestation period can be 22 months.
3. An elephant can normally go on calving till the age of 40 years only.
4. Among the States in India, the highest elephant population is in Kerala.
Which of the statements given above is/are correct?
Elephant herds are led by a matriarch and the gestation period can reach about 22 months (1 and 2); elephants calve beyond 40, and Karnataka (not Kerala) has the highest elephant population, so 3 and 4 are wrong.
All four — Ceylon frogmouth, coppersmith barbet, gray-chinned minivet and white-throated redstart — are birds.
1. Askot Wildlife Sanctuary
2. Gangotri National Park
3. Kishanpur Wildlife Sanctuary
4. Manas National Park
The musk deer inhabits high Himalayan forests — Askot (Uttarakhand) and Gangotri National Park (1 and 2); Kishanpur (terai) and Manas (Assam plains) are not musk-deer habitat.
1. The definition of 'Critical Wildlife Habitat' is incorporated in the Forest Rights Act
2006. 2. For the first time in India, the Baigas have been given habitat rights.
3. The Union Government has the power to notify an area as 'Critical Wildlife Habitat' under the Forest Rights Act 2006.
The FRA 2006 defines Critical Wildlife Habitat and the Baiga were the first to get habitat rights (1 and 2); CWH is notified by State governments, not the Union, so 3 is wrong.
1. Other than poaching, the use of synthetic fertilizers and agricultural chemicals in crop-fields near rivers is a reason for the decline in Ganges River Dolphins.
2. They are freshwater dolphins that are found only in India.
3. They are listed as endangered on the IUCN Red List.
Agro-chemical runoff is an added threat and the species is IUCN Endangered (1 and 3); the dolphin also occurs in Nepal and Bangladesh, not only India, so 2 is wrong.
1. Hedgehog
2. Marmot
3. Pangolin. To reduce the chance of being captured by predators, which of the above organisms rolls up and protects its vulnerable parts?
The hedgehog and the pangolin both roll into a protective ball (spines/scales facing out); the marmot flees to its burrow instead of rolling up.
Oysters are filter feeders — they strain plankton and particles from water passing over their gills.
Which one of the following is correct?
Per the official key both statements are correct, but the selection criteria in Statement 2 do not explain the (mis)attribution in Statement 1 — the programme is run by the Arbor Day Foundation and FAO.
Leaf-cutter and other ants are famous fungus-farmers — they cultivate fungus gardens on plant material for food.
The Golden Mahseer is a freshwater fish; the nightjar, spoonbill and ibis are all birds.
Statement-I: Marsupials are not naturally found in India.
Statement-II: Marsupials can thrive only in montane grasslands with no predators.
Which of the following is correct in respect of the above statements?
Marsupials are indeed not native to India (Statement I correct), but the claim that they thrive only in predator-free montane grasslands is false — marsupials occur mainly in Australia and the Americas across varied habitats.
1. Lion-tailed Macaque
2. Malabar Civet
3. Sambar Deer.
How many of the above are generally nocturnal or most active after sunset?
Only the Malabar civet is generally nocturnal; the lion-tailed macaque is diurnal and the sambar is chiefly crepuscular/diurnal — so only one is nocturnal.
1. They build nests by making burrows in the ground.
2. They store their food materials like nuts and seeds in the ground.
3. They are omnivorous.
How many of the above statements are correct?
Indian squirrels cache food in the ground and are omnivorous (statements 2 and 3); they nest in trees rather than digging ground burrows, so statement 1 is wrong.
Cicada (sound-producing), froghopper (record jumper) and pond skater (walks on water) are all insects.
I. It is an omnivorous crustacean.
II. Its natural habitat in India is only limited to some forest areas.
III. In its natural habitat, it is an arboreal species.
Which of the statements given above is/are correct?
The Gooty tarantula is a rare, tree-dwelling (arboreal) spider restricted to small forest patches in Andhra Pradesh (II and III correct); it is an arachnid, not an omnivorous crustacean, so I is wrong.
1. It is the world's largest land-dwelling invertebrate.
2. It is found in India only in the Great Nicobar Island.
3. It can climb trees and cut coconuts with its claws.
All three are correct: the coconut (robber) crab is the world's largest land invertebrate, in India it occurs only on Great Nicobar, and it climbs palms and cracks coconuts with its powerful claws.
1. It is an epiphytic orchid.
2. The species is endemic to North-east India.
3. It is the State flower of Arunachal Pradesh and Assam.
Which of the statements given above is/are correct?
The foxtail orchid is an epiphyte and is the State flower of both Arunachal Pradesh and Assam (1 and 3); it is widely distributed across South and South-East Asia, so it is not endemic to North-east India — statement 2 is wrong.
1. A sanctuary in North-east India is home to this ape species, listed as Endangered on the IUCN Red List.
2. They have specialized brachiation and can easily swing between trees.
3. They possess a strong and heavy build like gorillas, yet are remarkably agile tree climbers.
The Western Hoolock Gibbon (India's only ape) is IUCN Endangered and protected in NE Indian sanctuaries like Hollongapar, and it is a specialised brachiator (1 and 2); it is a small, light ape, not gorilla-like, so 3 is wrong.
1. It showcases how sustained local conservation efforts can contribute to the arrival and protection of international migratory birds.
2. It reflects the global success of advanced tracking technologies that guide migratory birds back to their stopover sites.
3. It confirms that Amur Falcons have adapted to permanent residency in India due to favourable habitat changes.
The Amur Falcon story at Doyang shows how community conservation turned Nagaland from a hunting ground into a safe stopover (statement 1); the birds navigate instinctively (not because tracking 'guides' them) and remain migratory (not permanent residents), so 2 and 3 are wrong.
1. It helps in the judicious use of pesticides along with other crop protection methods.
2. It is an effective method of preventing crop loss due to migratory pests.
3. It results in significant savings in the cost of cultivation.
IPM promotes judicious pesticide use and cuts cultivation costs (1 and 3); it is not particularly effective against mass migratory pests like locusts, so 2 is wrong.
1. Production of algae-based biofuels is possible in seas only and not on continents.
2. Setting up and engineering algae-based biofuel production requires a high level of expertise/technology until construction is completed.
3. Economically viable production necessitates the setting up of large-scale facilities which may raise ecological and social concerns.
Algae biofuels demand advanced technology and large-scale facilities that raise ecological/social concerns (2 and 3); algae can also be grown inland, not only in the sea, so 1 is wrong.
Permaculture mimics natural ecosystems and avoids monoculture, whereas conventional chemical farming is built around monocultures maintained with chemical inputs.
Flooded rice paddies emit methane from anaerobic decomposition and nitrous oxide from nitrogen fertilizer, making rice the key farm source of both gases.
1. It can be used directly as a fuel for internal combustion.
2. It can be blended with natural gas and used as a fuel for heat or power generation.
3. It can be used in the hydrogen fuel cell to run vehicles.
How many of the above statements are correct?
Green hydrogen can be burned directly in modified engines, blended into natural gas, and used in fuel cells to run vehicles — all three uses are valid.
1. Cement industry
2. Fertilizer industry
3. Iron and steel industry.
How many of the above can be significantly decarbonised by the use of green hydrogen as a source of energy?
Green hydrogen can decarbonise all three hard-to-abate sectors — cement (kiln heat), fertilizer (green ammonia) and steel (hydrogen-based direct reduction).
Statement I: India does not import apples from the United States of America.
Statement II: In India, the law prohibits the import of Genetically Modified food without the approval of the competent authority.
Which one of the following is correct?
India does import US apples (which are conventional, not GM), so Statement I is wrong; the law does require approval of the competent authority (GEAC) to import GM food, so Statement II is correct.
