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 2011: 16 questions
All years →- Q46 · Ecology & ecosystemsThe 2004 Tsunami made people realize that mangroves can serve as a reliable safety hedge against coastal calamities. How do mangroves function as a safety hedge?…
- Q53 · Protected areas & conservationTwo important rivers- one with its source in Jharkhand (and known by a different name in Odisha), and another, with its source in Odisha- merge at a place only a short distance from the coast of Bay o…
- Q56 · Ecology & ecosystemsIf a tropical rainforest is removed, it does not regenerate quickly as compared to a tropical deciduous forest. This is because…
- Q57 · Environmental laws, bodies & conventionsThe “Red Data Books” published by the International Union for Conservation of Nature and Natural Resource (IUCN) contain lists of Endemic plant and animal species present in the biodiversity hotspots.…
- Q58 · Protected areas & conservationWhich one of the following is not a site for the in-situ method of conservation of flora?…
- Q59 · Biodiversity, plants & animalsThree of the following criteria have contributed to the recognition of Western Ghats-Sri Lanka and Indo- Burma regions as hotspots of biodiversity: Species richness Vegetation density Endemism Ethno-b…
- Q60 · Ecology & ecosystemsConsider the following statements: Biodiversity is normally greater in the lower latitudes as compared to the higher latitudes. Along the mountain gradients, biodiversity is normally greater in the lo…
- Q61 · Ecology & ecosystemsBiodiversity forms the basis for human existence in the following ways: Soil formation Prevention of soil erosion Recycling of waste Pollination of crops…
- Q62 · Biodiversity, plants & animalsThe Himalayan Range is very rich in species diversity. Which one among the following is the most appropriate reason for this phenomenon?…
- Q64 · Ecology & ecosystemsThere is a concern over the increase in harmful algal blooms in the seawaters of India. What could be the causative factors for this phenomenon? Discharge of nutrients from the estuaries. Run-off from…
- Q65 · Pollution & wasteConsider the following: Carbon dioxide Oxides of Nitrogen Oxides of Sulphur…
- Q66 · Pollution & wasteThe formation of ozone hole in the Antarctic region has been a cause of concern. What could be the reason for the formation of this hole?…
- Q67 · Environmental laws, bodies & conventionsWith reference to India, consider the following Central Acts: Import and Export (Control) Act, 1947 Mining and Mineral development (Regulation) Act, 1957 Customs Act, 1962 Indian Forest Act, 1927…
- Q68 · Biodiversity, plants & animalsA sandy and saline area is the natural habitat of an Indian animal species. The animal has no predators in that area but its existence is threatened due to the destruction of its habitat. Which one of…
- Q82 · Pollution & wasteRecently, “oilzapper” was in the news. What is it?…
- Q88 · Ecology & ecosystemsConsider the following: Photosynthesis Respiration Decay of organic matter Volcanic action…
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 & agreementsजलवायु परिवर्तन पर भारत की अनुक्रिया के संदर्भ में निम्नलिखित कथनों पर विचार कीजिए : I. भारत की दीर्घकालिक निम्न उत्सर्जन विकास रणनीति (LT-LEDS), वर्ष 2070 तक नेट-जीरो उत…
- 2026 · Q22 · Biodiversity, plants & animalsवेस्टर्न हूलॉक गिबनों के संबंध में निम्नलिखित में से कौन-सा/कौन-से कथन सही है/हैं ?…
- 2026 · Q23 · Ecology & ecosystemsनिम्नलिखित में से कौन-सा/कौन-से, जलवायु अनुकूलन (climate resilience) के संदर्भ में गरान (मैंग्रोव) पारिस्थितिकी तंत्रों के संरक्षण हेतु तर्काधार की सर्वोत्तम व्याख्या करत…
- 2026 · Q27 · Biodiversity, plants & animalsमंगोलिया से प्रत्येक वर्ष नागालैंड के दोयंग झील में अमूर बाज़ों (Amur Falcons) के आगमन के संबंध में निम्नलिखित में से कौन-सा/कौन-से कथन सही है/हैं ?…
- 2026 · Q32 · Protected areas & conservationमाधव राष्ट्रीय उद्यान के संदर्भ में, निम्नलिखित में से कौन-सा/कौन-से कथन सही है/हैं ?…
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.
