UPSC Essentials brings to you its initiative of subject-wise quizzes. These quizzes are designed to help you revise some of the most important topics from the static part of the syllabus. Attempt today’s subject quiz on Environment and Geography to check your progress. Click Here to read the UPSC Essentials magazine for October 2026. Share your views and suggestions in the comment box or at manas.srivastava@indianexpress.com(a) 2 only(b) 1, 2, and 4 only(c) 1, 2, 4 and 5 only(d) 2, 3, and 5 onlyRelevance: The question tests knowledge of important wetland ecosystems, their geographical distribution and associated biodiversity in India. It is relevant to topics such as migratory birds, bird habitats, Ramsar sites and wetland conservation.Explanation— Thane Creek Flamingo Sanctuary, near Mumbai and Navi Mumbai, is one of India’s best-known urban flamingo-watching sites. Flamingos gather seasonally around the creek, mangroves and mudflats, with February to May generally considered a prominent viewing period.— The saline landscape of the Rann of Kutch supports flamingos at several locations. Its remote Flamingo City is a famous breeding site for greater flamingos, while other parts of the Rann support lesser flamingo nesting. The breeding site is in a restricted area, so it is not a regular tourist stop.— Nal Sarovar, a large shallow wetland near Ahmedabad, attracts flamingos and other migratory birds during winter. Chilika Lake is an important winter habitat for migratory waterbirds, including greater flamingos.Story continues below this ad— Pulicat Lake, spread across Andhra Pradesh and Tamil Nadu, attracts seasonal flamingos to its shallow waters and mudflats, particularly during the cooler months. It is also an important stop for several other migratory waterbirds.— Sambhar Lake, India’s largest inland salt lake, attracts flamingos and other migratory birds during the cooler months. Where and how many flamingos you can see varies with water levels and lake conditions.Therefore, option (b) is the correct answer.QUESTION 2With reference to the Blue Flag-tagged beaches, consider the following statements:1. The Blue Flag tag is given by the Ocean Foundation.2. India does not have Blue Flag-tagged beaches.Which of the statements given above is/are correct?(a) 1 only(b) 2 only(c) Both 1 and 2(d) Neither 1 nor 2Story continues below this adRelevance: The question is relevant to the themes of coastal and marine ecosystem conservation, sustainable tourism and environmental certification. It tests awareness of international environmental organisations, eco-labels and initiatives related to beach management.Explanation— In a first for Maharashtra, three of its beaches have been awarded an international certification that recognises beaches meeting stringent standards of environmental protection, water quality, safety and tourist facilities. The Ladghar and Guhagar beaches in Ratnagiri district, and the Shrivardhan beach in Raigad district, have earned the international Blue Flag certification. Only 22 beaches in India carry the certification, awarded by a Denmark-based non-governmental organisation. Hence, statement 2 is not correct.— The Blue Flag is an internationally recognised voluntary eco-label awarded to beaches, marinas and tourism boats that meet prescribed standards of environmental management, water quality, safety, accessibility and environmental education.— The programme is run by the Foundation for Environmental Education (FEE), an international non-governmental, non-profit organisation headquartered in Copenhagen, Denmark. It began in France in 1985 and has since grown into a global certification programme. Hence, statement 1 is not correct.Therefore, option (d) is the correct answer.Story continues below this adQUESTION 3The ‘Integrated Catalytic Thermo Cracking’ (ICTC) process is used for:(a) converting agriwastes into bio-crude(b) converting coal into synthetic natural gas(c) producing hydrogen from seawater through electrolysis(d) converting biomass into ethanol through microbial fermentationRelevance: The question links with the broader themes of renewable energy, sustainable fuel technologies and energy transition. It tests awareness of emerging technologies and their role in achieving environmental sustainability and energy security.Explanation— Greenjoules Private Ltd plans to set up a plant at Khed City, near Pune, for producing up to 2,00,000 litres of bio-crude per day from agricultural waste.— Greenjoules claims to have developed a proprietary Integrated Catalytic Thermo Cracking (ICTC) process for converting agriwastes – such as paddy straw and husk, groundnut and cashew shell, and sugarcane bagasse – in the presence of multiple catalysts at about 600 degrees Celsius into bio-crude. The bio-crude can be used in regular refineries to make renewable diesel and bio-naphtha.Therefore, option (a) is the correct answer.Story continues below this adQUESTION 4Which of the following are the constituents of smog?1. Particulate matter2. Nitrogen oxides3. Chlorofluorocarbons4. Dioxins5. Volatile organic compounds(a) 1, 2, and 3 only(b) 2, 3, and 4 only(c) 1, 2, and 5 only(d) 1, 2, 3, 4 and 5Relevance: The question is relevant to the syllabus themes of air pollution, atmospheric chemistry and environmental degradation. It is important in the context of urban air quality, photochemical reactions and India’s air pollution control measures.Explanation— Smog, derived from ‘smoke’ and ‘fog’, occurs when pollutants accumulate in the air, often reducing visibility. These include fine particulate matter, such as PM2.5 and PM10, and gases released by vehicles, industries and other sources.— Some pollutants, including nitrogen oxides and volatile organic compounds, can also react in sunlight to form ground-level ozone. This process produces what is known as photochemical smog, which is more common in sunny conditions.Story continues below this ad— PM10 refers to particles measuring 10 micrometres or less in diameter, while PM2.5 refers to finer particles measuring 2.5 micrometres or less. These particles can include dust, soot and smoke, as well as substances formed through chemical reactions involving gases in the atmosphere.— Fog, on the other hand, consists of tiny water droplets suspended close to the ground. It forms when moist air cools and water vapour condenses into droplets, reducing visibility. Unlike fog, smog contains harmful pollutants that can affect human health. Fog and smog can also occur together.— CFCs are primarily associated with stratospheric ozone depletion and are not considered conventional constituents of smog.— Dioxins are persistent organic pollutants released through certain combustion and industrial processes. They are not recognised as standard constituents of smog.Therefore, option (c) is the correct answer.Story continues below this adQUESTION 5With reference to the Air Quality Index (AQI), consider the following statements:1. It was launched in 2014 as part of the government’s Swachh Bharat campaign.2. It is a colour-coded index that helps explain the condition of the air.3. The AQI measures all pollutants present in the air.How many of the statements given above are correct?(a) Only one(b) Only two(c) All three(d) NoneRelevance: It is relevant to the syllabus themes of air pollution, environmental monitoring and pollution control mechanisms. It is important in the context of urban air pollution, public health, environmental standards and sustainable urban development.ExplanationStory continues below this ad— AQI is a number which measures air quality. The higher the AQI, the worse the air. The AQI used in India was launched in 2014 as part of the government’s Swachh Bharat campaign. The colour-coded index helps explain the condition of the air and the measures necessary to mitigate the situation depending on its severity. Hence, statements 1 and 2 are correct.— AQI does not measure all pollutants present in the air. The index converts measurements of up to eight major air pollutants into a single number, category and colour. These include particulate matter (PM2.5 and PM10), nitrogen dioxide, sulphur dioxide, ozone, carbon monoxide, ammonia and lead. Hence, statement 3 is not correct.— Each pollutant’s concentration is converted into a separate sub-index based on established health-related thresholds. The highest sub-index determines the overall AQI, rather than an average of all pollutants.— There are six categories of AQI, namely ‘Good’ (0-50), ‘Satisfactory’ (51-100), ‘Moderate’ (101-200), ‘Poor’ (201-300), ‘Very Poor’ (301-400), and ‘Severe’ (401-500).Therefore, option (b) is the correct answer.Previous Daily Subject-Wise-QuizDaily Subject-wise quiz — History, Culture, and Social Issues (Week 167)Daily subject-wise quiz — Polity and Governance (Week 188)Daily subject-wise quiz — Science and Technology (Week 188)Daily subject-wise quiz — Economy (Week 187)Daily subject-wise quiz — Environment and Geography (Week 187)Daily subject-wise quiz – International Relations (Week 187)Subscribe to our UPSC newsletter and stay updated with the news cues from the past week.Stay updated with the latest UPSC articles by joining our Telegram channel – IndianExpress UPSC Hub, and follow us on Instagram and X