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 2013: 17 questions
All years →- Q52 · Ecology & ecosystemsWhich of the following is/are unique characteristic/characteristics of equatorial forests? Presence of tall, closely set trees with crowns forming a continuous canopy Coexistence of a large number of …
- Q66 · Protected areas & conservationConsider the following pairs: Corbett National Park — Ganga Kaziranga National Park — Manas Silent Valley National Park — Kaveri…
- Q67 · Protected areas & conservationConsider the following pairs: Nokrek Biosphere Reserve - Garo Hills Logtak (Loktak) Lake - Barail Range Namdapha National Park - Dafla Hills…
- Q69 · Ecology & ecosystemsWith reference to the food chains in ecosystems, which of the following kinds of organism is/are known as decomposer organism/organisms? Virus Fungi Bacteria…
- Q70 · Ecology & ecosystemsIn the grasslands, trees do not replace the grasses as a part of an ecological succession because of:…
- Q71 · Ecology & ecosystemsWhich one of the following is the correct sequence of ecosystems in the order of decreasing productivity?…
- Q72 · Ecology & ecosystemsWith reference to food chains in ecosystems, consider the following statements: A food chain illustrates the order in which a chain of organisms feeds upon each other. Food chains are found within the…
- Q73 · Ecology & ecosystemsWhich one of the following terms describes not only the physical space occupied by an organism but also its functional role in the community of organisms?…
- Q75 · Pollution & wasteWhich of the following can be found as pollutants in the drinking water in some parts of India? Arsenic Sorbitol Fluoride Formaldehyde Uranium…
- Q76 · Pollution & wasteDue to improper/indiscriminate disposal of old and used computers or their parts, which of the following are released into the environment as e-waste? Beryllium Cadmium Chromium Heptachlor Mercury Lea…
- Q77 · Pollution & wasteAcid rain is caused by the pollution of environment by…
- Q78 · Pollution & wastePhotochemical smog is a resultant of the reaction among…
- Q81 · Biodiversity, plants & animalsConsider the following fauna of India: Gharial Leatherback turtle Swamp deer…
- Q82 · Biodiversity, plants & animalsConsider the following: Star tortoise Monitor lizard Pygmy hog Spider monkey…
- Q83 · Biodiversity, plants & animalsConsider the following animals: Sea cow Sea horse Sea lion…
- Q85 · Biodiversity, plants & animalsIn which of the following States is lion-tailed macaque found in its natural habitat? Tamil Nadu Kerala Karnataka Andhra Pradesh…
- Q86 · Biodiversity, plants & animalsMycorrhizal biotechnology has been used in rehabilitating degraded sites because mycorrhiza enables the plants to Resist drought and increase absorptive area Tolerate extremes of pH Resist disease inf…
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.
