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 July 2025. Share your views and suggestions in the comment box or at manas.srivastava@indianexpress.comQUESTION 1With reference to the Xanthism, consider the following statements:1. It is considered extremely rare across the animal kingdom.2. It causes excessive yellow or golden hues due to a lack of red pigmentation.3. It is only observed in fish and is not observed in reptiles and birds.How many of the statements given above are correct?(a) Only one(b) Only two(c) All three(d) NoneExplanation— A rare, vividly orange nurse shark has been discovered off the coast of Costa Rica, baffling scientists and prompting renewed interest in marine pigmentation anomalies.— According to researchers from the Federal University of Rio Grande, this peculiar colouration is due to xanthism—also known as xanthochroism—a rare condition of pigmentation.Story continues below this ad— Xanthism causes excessive yellow or golden hues due to a lack of red pigmentation. It has never been documented before in cartilaginous fish, the group of species that includes sharks, rays, and skates, in the Caribbean. Hence, statement 2 is correct.— Xanthism is considered extremely rare across the animal kingdom. It’s previously been observed in a small number of fish, reptiles, and birds. For instance, vivid yellow morphs have appeared in freshwater fish, while parrots and canaries have been seen with golden feathers. Occasional reports have also emerged of yellow snakes and lizards exhibiting the condition. Hence, statement 1 is correct and statement 3 is not correct.Therefore, option (b) is the correct answer.QUESTION 2Consider the following statements about Western Disturbances:1. These are rain-bearing wind systems.2. They are embedded in the subtropical westerly jet stream.3. They are most abundant during the boreal winter months.How many of the statements given above are correct?(a) Only one(b) Only two(c) All three(d) NoneExplanation— Western Disturbances are rain-bearing wind systems that begin east of Afghanistan and Iran and pick up moisture from the Mediterranean, Black, Caspian, and Arabian Seas. Hence, statement 1 is correct.— These are examples of extratropical cyclones caused by low-pressure zones created by the interplay of polar and tropical winds. Western Disturbances are embedded in the subtropical westerly jet stream, which is a high-altitude, fast-moving air movement that runs from west to east in the Earth’s atmosphere and passes over the Himalayan and Tibetan highlands. Hence, statement 2 is correct.Story continues below this ad— They are most abundant during the boreal winter months (December to March) and have an impact on the weather in India, notably the northwest, Pakistan, Afghanistan, and Tajikistan. Hence, statement 3 is correct.Therefore, option (c) is the correct answer.QUESTION 3Under the Wildlife Protection Act, 1972, development projects requiring land in or around tiger reserves or corridors require statutory clearance from the:(a) Standing Committee of the National Board for Wildlife (SC-NBWL).(b) National Tiger Conservation Authority (NTCA) alone.(c) Ministry of Environment, Forest and Climate Change without NBWL approval.Story continues below this ad(d) State Board for Wildlife (SBWL) as the final authority.Explanation— In a volte-face less than a month after it affirmed before the Bombay High Court that the identification of tiger corridors must take cognizance of multiple scientific studies and parameters, the National Tiger Conservation Authority (NTCA) issued a clarification yesterday, limiting the number of such corridors, primarily, to only 32 “least cost pathways” identified in 2014.— Tiger corridors are vital wildlife pathways that connect tiger habitats, enabling animal movement, gene flow, and long term survival. Under the Wildlife Protection Act, 1972, development projects requiring land in or around tiger reserves or corridors require statutory clearance from the standing committee of the National Board for Wildlife (SC-NBWL).Therefore, option (a) is the correct answer.QUESTION 4With reference to canyons beneath Antarctica, consider the following statements:Story continues below this ad1. In West Antarctica, canyon systems are more branched and extensive, suggesting a long history linked to stable ice sheets.2. In East Antarctica, canyons are steeper, straighter, and shorter, which points to more recent and episodic glacial activity.Which of the statements given above is/are correct?(a) 1 only(b) 2 only(c) Both 1 and 2(d) Neither 1 nor 2Explanation— Scientists have discovered 332 submarine canyons beneath Antarctica’s ice, a fivefold increase on what was previously known.— The new map, published in the journal Marine Geology, was created using high-resolution bathymetric data gathered from more than 40 international research expeditions. Researchers from the University of Barcelona and University College Cork led the study.Story continues below this ad— The research highlights differences between East and West Antarctica. In the east, canyon systems are more branched and extensive, suggesting a long history linked to stable ice sheets. In the west, canyons are steeper, straighter, and shorter, which points to more recent and episodic glacial activity. Hence, statements 1 and 2 are not correct.— The canyons also play a key role in the way Antarctic waters move. Dense, salty water from the continental shelf flows down into the Southern Ocean through these channels, driving global circulation that helps regulate temperature and nutrients across the world’s oceans. At the same time, warm water from the deep ocean can rise through the canyons, reaching beneath ice shelves and speeding up melting.Therefore, option (d) is the correct answer.QUESTION 5With reference to the ‘Naegleria fowleri’, consider the following statements:1. It is a free-living amoeba or a single-celled living organism.Story continues below this ad2. It lives in warm, fresh water and soil around the world.3. It infects people when it enters the body through the nose.Which of the statements given above are correct?(a) 1 and 2 only(b) 2 and 3 only(c) 1 and 3 only(d) 1, 2 and 3Explanation— Three cases of the rare primary amoebic meningoencephalitis (PAM) have been reported in Kerala in recent days, leading to the death of a nine-year-old and infecting a three-month-old baby. PAM is a rare brain infection caused by Naegleria fowleri, also called ‘brain-eating amoeba’.— PAM is caused by Naegleria fowleri, a free-living amoeba or a single-celled living organism. It lives in warm, fresh water and soil around the world, and infects people when it enters the body through the nose. Higher temperatures of up to 115°F (46°C) are conducive to its growth, and it can survive for short periods in warm environments.Therefore, option (d) is the correct answer.Story continues below this adPrevious Daily Subject-Wise-QuizDaily Subject-wise quiz — History, Culture, and Social Issues (Week 122)Daily subject-wise quiz — Polity and Governance (Week 124)Daily subject-wise quiz — Science and Technology (Week 124)Daily subject-wise quiz — Economy (Week 124)Daily subject-wise quiz — Environment and Geography (Week 123)Daily subject-wise quiz – International Relations (Week 123)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.