Environment and Ecology: UPSC Previous Year Questions (Prelims)
259 previous year UPSC Prelims Environment and Ecology questions are on this page, from 1996 to 2025, in 10 chapters. Species, Pollution, Environmental Laws and Conventions and Climate Change are the largest, and recent papers lean on statement-pairs about news items: Direct Air Capture, the Nature Restoration Law, PFAS and the Peacock tarantula. Filter by chapter to revise one area, or by year for a single paper.
Explanations state facts as of the year each question was asked; words like “recently” refer to that year.
Showing 211–220 of 259 questions
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UPSC 2012Environment and Ecology · Biodiversity
Q211. How does the National Biodiversity Authority (NBA) help in protecting Indian Agriculture? 1. NBA checks the biopiracy and protects the indigenous and traditional genetic resources. 2. NBA directly monitors and supervises the 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. Which of the statements given above is/are correct?
Explanation
Statement 1 is correct: The National Biodiversity Authority(NBA) plays a crucial role in preventing biopiracy which is the unauthorized use of biological resources or traditional knowledge without fair compensation or consent. The NBA ensures that access to India’s biological resources (including agricultural crops, medicinal plants, and traditional knowledge) is regulated. This helps protect India’s indigenous and traditional genetic resources from exploitation by foreign entities or corporations.
Statement 2 is incorrect: NBA does not directly supervise scientific research on genetic modification (GM) of crops. The regulation of Genetically Modified (GM) crops falls under the Genetic Engineering Appraisal Committee (GEAC) which functions under the Ministry of Environment, Forest and Climate Change.
Statement 3 is correct: The NBA’s approval is mandatory before filing any Intellectual Property Rights (IPR) application for patents related to biological resources originating in In-dia. This prevents foreign companies from claiming patents on Indian plants, seeds, and traditional medicines without sharing benefits with local communities.
UPSC 2012Environment and Ecology · Agriculture and Environment
Q212. Consider the following agricultural practices: 1. Contour bunding 2. Relay cropping 3. Zero tillage In the context of global climate change, which of the above helps/ help in carbon sequestration/storage in the soil?
Explanation
Terrestrial Carbon sequestration is the process through which carbon dioxide from the atmosphere is absorbed by trees and plants through photosynthesis and stored as carbon in soil and biomass. Option 3 is correct: Zero Tillage is the process where the crop seed will be sown through drillers without prior land preparation and distributed in the soil where previous crop stubbles are present. Zero tillage not only reduces the cost of cultivation it also reduces the soil erosion, crop duration, irrigation requirement and weed effect which is better than tillage. Zero tillage is environmentally safe because it helps in reducing greenhouse effect through carbon sequestration. Options 1 and 2 are incorrect:
Contour bundling involves the construction of banks along the contours. Terracing and contour bunding divide the hill slope into numerous small slopes, check the flow of water, promote absorption of water by soil and save soil from erosion. Retaining walls of terraces control the flow of water and help in reducing soil erosion. Relay Cropping is the process of growing one crop, then planting another crop (usually a cover crop) in the same field before harvesting the first. This helps avoid competition between the main crop and the intercrop. It also uses the field for a longer time, since the cover crop usually continues to grow after the main crop is harvested.
UPSC 2012Environment and Ecology · Climate Change
Q213. Consider the following statements: Chlorofluorocarbons, known as ozone-depleting substances, are used: 1. In the production of plastic foams. 2. In the production of tubeless tyres. 3. In cleaning certain electronic components. 4. As pressurizing agents in aerosol cAns: Which of the statements given above is/are correct?
Explanation
Chlorofluorocarbons, Hydrochlorofluorocarbons, Carbon tetrachloride, Methyl chloroform, Methyl chloroform, Ha-lons, Methyl bromide, etc. are Ozone Depleting Substances. Chlorofluorocarbons (CFCs) also referred to as ozone depleting materials, are used to make plastic foams, cleaning electronic components, and pressurising aerosol cAns: They are non-toxic, nonflammable chemicals containing atoms of carbon, chlorine and fluorine. Statements 1, 3 and 4 are correct: Chlorofluorocarbons, known as ozone-depleting substances, are used in the production of plastic foams, in cleaning electronic components, and as pressurising agents in aerosol.
Statement 2 is incorrect: Chlorofluorocarbons are not used in the production of tubeless tyres. Tubeless tyre is basically a clincher tyre inflated onto a rim with no inner tube. Instead of an inner tube holding the air pressure, an airtight chamber is created with a tubeless-specific tyre, developed with a special (commonly carbon) bead, and a compatible rim.
UPSC 2012Environment and Ecology · Climate Change
Q214. The increasing amount of carbon dioxide in the air is slowly raising the temperature of the atmosphere, because it absorbs
Explanation
Greenhouse Effect is a naturally occurring phenomenon that warms and covers the lower atmosphere of the planet, keeping it at a temperature where life may survive. The earth’s cooling and warming are balanced by them. Without this, the current 15 degrees Celsius average temperature of the earth’s surface would be -19 degrees Celsius. Human-induced greenhouse gas emissions upset the natural balance & lead to increased warmth.
Option (d) is correct: Carbon dioxide absorbs the infrared (IR) radiation emitted by the Earth’s surface. When sunlight reaches the Earth it warms the surface, which then re-emits this energy as infrared radiation. CO₂ molecules absorb this IR radiation, trapping heat in the atmosphere and causing the temperature to rise.The increasing amount of carbon dioxide in the air is slowly raising the temperature of the atmosphere because it absorbs the infrared part of the solar radiation. It absorbs energy with a wavelength of 15 m (micrometres).
UPSC 2012Environment and Ecology · Environmental Laws, Conventions and Policies
Q215. The National Green Tribunal Act, 2010 was enacted in consonance with which of the following provisions of the Constitution of India? 1. Right to healthy environment, construed as a part of Right to life under Article 21. 2. Provision of grants for raising the level of administration in the Scheduled Areas for the welfare of Scheduled Tribes under Article 275(1). 3. Powers and functions of Gram Sabha as mentioned under Article 243(A). Select the correct answer using the codes given below:
Explanation
National Green Tribunal (NGT) Act, 2010 aims at efficient & quick resolution of environmental disputes (within 6 months of appeal) in order to lessen the burden of litigation in the higher courts. The Act established National-Green Tribunal with jurisdiction over all civil cases involving substantial questions relating to the environment. Tribunal is guided by principles of natural justice & its order is executable as a decree of a civil court. Although the NGT’s orders are final, they may be contested in the SC within 90 days.
Statement 1 is correct: The NGT Act is grounded in the fundamental right to a clean and healthy environment, which is integral to the Right to Life under Article 21. Landmark judgments, such as Subhash Kumar v. State of Bihar (1991) and M.C. Mehta cases, have expanded the interpretation of Article 21 to include environmental protection. Statements 2 and 3 are incorrect: Provisions mentioned in statements 2 and 3 have no bearing upon National-Green Tribunal:
Article 275(1) of the Constitution of India guarantees grants-in-aid from the Consolidated Fund of India each year for promoting the welfare of Scheduled Tribes. Infrastructure development schemes like protected drinking water, road connectivity, electricity and housing are provided under this scheme. 243A provides that a Gram Sabha may exercise such powers and perform such functions at the village level as the Legislature of a State may, by law, provide.
UPSC 2012Environment and Ecology · Protected Areas for the Biodiversity Conservation
Q216. Consider the following protected areas: 1. Bandipur 2. Bhitarkanika 3. Manas 4. Sunderbans Which of the above are declared Tiger Reserves?
Explanation
Project Tiger was initiated in 1973 under the Wild-life Protection Act, 1972, with the National Tiger Conservation Authority (NTCA) overseeing the implementation. The project was launched with the primary goal to protect the Bengal tiger, enhance their population, and safeguard their habitats through the establishment of Tiger Reserves. The project has been highly successful, expanding to include a range of conservation efforts. A Tiger Reserve is a protected area legally designated for the conservation of striped big cats. It can also be classified as a national park or wildlife sanctuary. For example, Sariska Tiger Reserve is also a national park because it was initially established as a na-tional park before being dedicated to tiger conservation.
UPSC 2012Environment and Ecology · Protected Areas for the Biodiversity Conservation
Q217. In which one among the following categories of protected areas in India are local people not allowed to collect and use the biomass?
Explanation
According to the Ministry of Environment, Forest and Climate Change, a national park is defined as an area, whether within a sanctuary or not, that can be designated by the state government due to its ecological, faunal, floral, geomorphologi-cal, or zoological significance. The purpose of this designation is to protect, propagate, or develop the wildlife and its environment. In National Parks, local people are generally not allowed to collect and use the biomass or any resources for subsistence purposes. The primary objective of National Parks is the protection of biodiversity and preservation of ecosystems. These parks are strictly protected under the Wildlife Protection Act, 1972, and human activities, including the collection of resources like firewood, grazing, and hunting, are prohibited unless specifically allowed for research or management purposes.
UPSC 2012Environment and Ecology · Species
Q218. Vultures which used to be very common in Indian countryside some years ago are rarely seen nowadays. This is attributed to:
Explanation
The drastic decline in the vulture population in India is primarily attributed to the use of a veterinary drug called diclofenac. This drug was commonly administered to cattle to treat inflammation and pain. However, when vultures fed on the car-casses of cattle that had been treated with diclofenac, they suffered from kidney failure and fatal toxicity, leading to a sharp decline in their population.
UPSC 2012Environment and Ecology · Species
Q219. Consider the following kinds of organisms: 1. Bat 2. Bee 3. Bird Which of the above is/are pollinating agent/agents?
Explanation
When a pollen grain moves from the anther (male part) of a flower to the stigma (female part), pollination happens and it is the first step in a process that produces seeds, fruits, and the next generation of plants. Vectors that move pollen within the flower and from flower to flower are called pollinators.
Option (d) is correct:
Pollination is the transfer of pollen grains from the stamens (the flower parts that produce them) to the ovule-bearing organs or to the ovules (seed precursors) themselves. There are two categories of pollinators, i.e. invertebrate pollinators which includes bees, moths, flies, wasps, beetles and butterflies and verte-brate pollinators which has monkeys, rodents, lemurs, tree squirrels, bats and birds. The fruit bats (also known as megabats) and nectar-feeding bats are particularly involved in pollination. Bats are vital for the pollination of various species, including certain species of cacti, bananas, and agave plants, which rely on them for reproduction. Bees are some of the most efficient and well-known pollinators. Bees are responsible for pollinating a significant portion of the world’s food crops. Certain species of birds, particularly hummingbirds and some species of sunbirds, are also important pollinators. They feed on nectar and, in the process, move pollen from one flower to another. This form of pollination is common in plants with red or orange flowers that attract birds and require birds with long bills or beaks for feeding.
UPSC 2012Environment and Ecology · Species
Q220. The Government of India encourages the cultivation of ‘sea buckthorn’. What is the importance of this plant: 1. It helps in controlling soil erosion and in preventing desertification. 2. It is a rich source of biodiesel. 3. It has nutritional value and is well-adapted to live in cold areas of high altitudes. 4. Its timber is of great commercial value. Which of the statements given above is/are correct?
Explanation
Seabuckthorn (soil binding, rich in vitamins) is a shrub which produces an orange-yellow coloured edible berry. It can be found in India above treeline in the Himalayan region, usually in arid places like the cold deserts of Ladakh and Spiti. Seabuckthorn grows naturally in Lahaul, Spiti, and some regions of Kinnaur in Himachal Pradesh. Statements 1 and 3 are correct: Seabuckthorn is a soil-bind-ing plant which prevents soil-erosion, it also has commercial value, as it is used in making juices, jams, nutritional capsules etc.
Statement 2 is incorrect: While sea buckthorn has various uses, including medicinal and nutritional, it is not primarily known for being a biodiesel source. While some studies have explored its potential as a biofuel, it is not widely regarded as a primary source of biodiesel.
Statement 4 is incorrect: Sea buckthorn does not have significant commercial value for its timber. The plant is primarily valued for its fruits, oils, and medicinal properties, not for timber production.
Answer key for these questions
Q
UPSC year
Correct answer
211
2012
(c) 1 and 3 only
212
2012
(b) 3 only
213
2012
(c) 1, 3 and 4 only
214
2012
(d) The infrared part of the solar radiation.
215
2012
(a) 1 only
216
2012
(b) 1, 3 and 4 only
217
2012
(b) National Parks
218
2012
(b) a drug used by cattle owners for treating their discased cattle
219
2012
(d) 1, 2 and 3
220
2012
(c) 1 and 3 only
What UPSC has tested in Environment and Ecology
Species questions ask for classification and habitat: which is an insect, a filter feeder, or not a bird, and where an animal is found.
Law and convention questions ask which body or instrument covers what, such as the Wildlife Protection Act’s schedules, the e-Waste Rules and the Ramsar Convention.
Climate questions in 2025 covered Article 6 of the Paris Agreement, COP28, Direct Air Capture and wet-bulb temperatures.
Protected-area questions combine locations with distinctive features, such as the swamp park of Keibul Lamjao and Critical Tiger Habitats.
Frequently asked questions
How many previous year UPSC questions are there on Environment and Ecology?
This page covers 259 previous year UPSC Prelims GS Paper-I questions on Environment and Ecology, asked from 1996 to 2025. Each has the correct answer and an explanation.
Which Environment chapters have the most questions?
Species has the most with 43 questions, followed by Pollution and Environmental Laws, Conventions and Policies with 39 each, and Climate Change with 30. Environmental Organisations and Miscellaneous are the smallest.
How can I revise Environment and Ecology using these questions?
Take a chapter at a time with the Chapter filter, attempt the questions and read the facts UPSC has tested. Revise Species and Protected Areas with a map and a list of national parks at hand.
Are the 2025 Environment questions included?
Yes. The 2025 paper’s Environment questions on activated carbon, cement emissions, COP28, Article 6, Direct Air Capture, the Gooty tarantula, plastics and the Nature Restoration Law are included with full explanations.