Prelims GS I · 245 questions · 2011–2026
Environment & ecology: every Prelims question, by topic
UPSC syllabus: “General issues on Environmental ecology, Bio-diversity and Climate Change - that do not require subject specialization.” Below, the topics inside it — most asked first — and how often each came up year by year.
Environment & ecology in Prelims 2021: 20 questions
All years →- Q16 · Pollution & waste'R2 Code of Practices' constitutes a tool available for promoting the adoption of…
- Q17 · Pollution & wasteWhy is there a concern about copper smelting plants? They may release lethal quantities of carbon monoxide into environment. The copper slag can cause the leaching of some heavy metals into environmen…
- Q18 · Pollution & wasteWith reference to furnace oil, consider the following statements: It is a product of oil refineries. Some industries use it to generate power. Its use causes sulphur emissions into environment.…
- Q19 · Climate change & agreementsWhat is blue carbon?…
- Q20 · Ecology & ecosystemsIn the nature, which of the following is/are most likely to be found surviving on a surface without soil? Fern Lichen Moss Mushroom…
- Q21 · Biodiversity, plants & animalsWhich one of the following is used in preparing a natural mosquito repellent?…
- Q22 · Ecology & ecosystemsConsider the following kinds of organisms: Copepods Cyanobacteria Diatoms Foraminifera…
- Q23 · Biodiversity, plants & animalsConsider the following animals: Hedgehog Marmot Pangolin…
- Q24 · Environmental laws, bodies & conventionsWith reference to the 'New York Declaration on Forests', which of the following statements are correct? It was first endorsed at the United Nations Climate Summit in 2014. It endorses a global timelin…
- Q25 · Pollution & wasteMagnetite particles, suspected to cause neurodegenerative problems, are generated as environmental pollutants from which of the following? Brakes of motor vehicles Engines of motor vehicles Microwave …
- Q26 · Biodiversity, plants & animalsWhich one of the following is a filter feeder?…
- Q27 · Ecology & ecosystemsIn case of which one of the following biogeochemical cycles, the weathering of rocks is the main source of release of nutrient to enter the cycle?…
- Q28 · Ecology & ecosystemsWhich of the following are detritivores? Earthworms Jellyfish Millipedes Seahorses Woodlice…
- Q29 · Climate change & agreementsThe 'Common Carbon Metric', supported by UNEP, has been developed for…
- Q30 · Ecology & ecosystemsWhich of the following have species that can establish symbiotic relationship with other organisms? Cnidarians Fungi Protozoa…
- Q60 · Ecology & ecosystems"Leaf litter decomposes faster than in any other biome and as a result the soil surface is often almost bare. Apart from trees, the vegetation is largely composed of plant forms that reach up into the…
- Q61 · Ecology & ecosystemsThe vegetation of savannah consists of grassland with scattered small trees, but extensive areas have no trees. The forest development in such areas is generally kept in check by one or more or a comb…
- Q63 · Biodiversity, plants & animalsConsider the following statements: Moringa (drumstick tree) is a leguminous evergreen tree. Tamarind tree is endemic to South Asia. In India, most of the tamarind is collected as minor forest produce.…
- Q74 · Pollution & wasteBisphenol A (BPA), a cause of concern, is a structural/key component in the manufacture of which of the following kinds of plastics?…
- Q75 · Pollution & waste‘Triclosan’, considered harmful when exposed to high levels for a long time, is most likely present in which of the following?…
Environment & ecology in UPSC Prelims at a glance
UPSC has asked 245 questions on Environment & ecology in GS Paper I from 2011 to 2026 — about 15 a year, the most in 2014 (23). The most-asked topic is Biodiversity, plants & animals (62 questions).
| Year | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 | 2026 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Questions | 16 | 18 | 17 | 23 | 15 | 17 | 13 | 11 | 18 | 12 | 20 | 16 | 13 | 14 | 13 | 9 |
Counted from UPSC's own papers in the Vault, each question under its main subject · updated 8 Nov 2026.
- Biodiversity, plants & animals62 questions · asked in 15 of 16 years
- Pollution & waste43 questions · asked in 15 of 16 years
- Climate change & agreements40 questions · asked in 14 of 16 years
- Environmental laws, bodies & conventions40 questions · asked in 15 of 16 years
- Ecology & ecosystems33 questions · asked in 11 of 16 years
- Protected areas & conservation27 questions · asked in 13 of 16 years
Latest questions
- 2026 · Q21 · Climate change & agreementsConsider the following statements with reference to India's response to climate change: I. India's Long-Term Low Emission Development Strategy (LT-LEDS) is a crucial tool…
- 2026 · Q22 · Biodiversity, plants & animalsWith respect to the Western Hoolock Gibbons, which of the following statements is/are correct?…
- 2026 · Q23 · Ecology & ecosystemsWhich of the following best explain(s) the rationale for protecting mangrove ecosystems in the context of climate resilience?…
- 2026 · Q27 · Biodiversity, plants & animalsWhich of the following statements with regard to the arrival of Amur Falcons at Doyang Lake in Nagaland each year from Mongolia is/are correct?…
- 2026 · Q32 · Protected areas & conservationWith reference to Madhav National Park, which of the following statements is/are correct?…
The same ground in Mains
These official Mains syllabus lines cover Environment & ecology. Prelims facts become Mains arguments.
Environment & ecology PYQs as a PDF — free
All 48 PDFs →Every Environment & ecology question from 2011 to 2026, topic-wise, with answers and explanations — 120 pages. Free; sign up once.
Environment & ecology PYQs: quick answers
How many Environment & ecology questions has UPSC asked in Prelims from 2011 to 2026?
245 questions in GS Paper I — about 15 a year, the most in 2014 (23). Every one is on this page, under its topic, with UPSC's answer and an explanation.
Which Environment & ecology topic does UPSC ask most in Prelims?
Biodiversity, plants & animals: 62 questions between 2011 and 2026, asked in 15 of 16 years. The topics are listed above, most asked first, each with its year-by-year trend.
Are the answers UPSC's official answer keys?
From 2016, yes: every answer is from UPSC's final answer key (2016–2025); for 2011–2015, where UPSC published no key online, each answer is worked out from official sources and reviewed independently; for 2026 UPSC has so far published a provisional key, and those answers are labelled. Explanations cite official sources — NCERT and government pages first.
Can I download the Environment & ecology PYQs as a PDF?
Yes — a print-ready PDF of every Environment & ecology question with answers and explanations (120 pages, 2.4 MB), free after a one-time sign-up, from the Vault's downloads page.
Counted from UPSC's own papers in the Vault; answers are UPSC's keys.
