UPSC Prelims 2021 Question Paper with Answers

When the Constitution came into force on 26 January 1950, the original Preamble described India as a 'Sovereign Democratic Republic' — the words 'Socialist' and 'Secular' were absent. These two words were inserted by the 42nd Constitutional Amendment Act, 1976 during the Emergency period under Prime Minister Indira Gandhi, making India officially a 'Sovereign Socialist Secular Democratic Republic.' The 42nd Amendment also changed 'unity of the nation' to 'unity and integrity of the nation.' UPSC frequently tests this amendment's specific changes to the Preamble. The absence of 'Socialist' and 'Secular' in 1950 is a recurring factual question — candidates must remember the original formulation versus the post-1976 version.

The 44th Constitutional Amendment Act, 1978 (under the Janata Party government under Morarji Desai) deleted the Right to Property from Part III (Fundamental Rights) and relocated it as Article 300A under Part XII — making it a constitutional legal right, not a Fundamental Right. As a constitutional legal right, it is available to any person (including non-citizens, companies, and juridical persons), unlike some Fundamental Rights which are available only to citizens. A person can be deprived of their property only by authority of law, not by executive order. The contrast with the Fundamental Right era (pre-1978) is significant: previously, the state could not acquire property without compensation (Articles 19(1)(f) and 31); now property can be acquired by law with fair compensation under broader terms. UPSC tests this transition frequently.

INDEPENDENT JUDICIARY is the most ESSENTIAL feature that confirms a polity is federal in character. The reasoning: in a federal system, there are constitutional disputes between the Centre and States, and between States — these can only be resolved fairly by an INDEPENDENT and IMPARTIAL judiciary that stands above both levels of government. Without judicial independence, the federal compact would collapse — the Centre or States could violate constitutional provisions with impunity. The JUDICIAL REVIEW power held by the Supreme Court of India enables it to invalidate central or state laws that violate the Constitution, including federal arrangements. K.C. WHEARE's definition of federalism (in "Federal Government", 1946) emphasized: (a) division of powers between Centre and units, (b) supremacy of the constitution, (c) AN INDEPENDENT JUDICIARY to interpret the constitution and resolve disputes. The third element is crucial. (b) Union Legislature with elected representatives from states — Many UNITARY systems also have elected representatives in their parliament; this is not unique to federalism. (c) Union Cabinet with regional party representatives — Coalition politics, not a structural federal feature. (d) Fundamental Rights enforceable by courts — While important, this is a separate principle (rule of law/protection of citizens) and is found in unitary systems as well. The correctness of "independent judiciary" is the structural feature that DISTINGUISHES federal from unitary systems. UPSC 2021 official answer: A.

The classical definition of the STATE in political science includes FOUR ESSENTIAL ELEMENTS: (1) POPULATION — a community of persons; (2) TERRITORY — a definite geographical area; (3) GOVERNMENT — an organized political authority; (4) SOVEREIGNTY — independence from external control. Option A captures all four elements concisely: "A community of persons (POPULATION) permanently occupying a definite territory (TERRITORY) independent of external control (SOVEREIGNTY) and possessing an organized government (GOVERNMENT)." This is essentially the formulation of MONTEVIDEO CONVENTION (1933) on Rights and Duties of States, which lays down the criteria for statehood in international law: (a) a permanent population, (b) a defined territory, (c) government, (d) capacity to enter into relations with other states. SOVEREIGNTY — both internal (supreme within its territory) and external (independent from foreign control) — is the most distinctive feature of a state, distinguishing it from other political units like provinces, municipalities, or international organizations. (b) Adds protective functions but omits the crucial element of SOVEREIGNTY (independence from external control) explicitly. (c) Defines a NATION (with shared culture, tradition) rather than a STATE — nations and states are different concepts. (d) Describes specific governmental arrangements (executive responsible to central authority, independent judiciary) which are features of particular kinds of states (parliamentary democracies) — not the universal definition of statehood. UPSC 2021 official answer: A.

SEPARATION OF POWERS is the best safeguard of liberty in a liberal democracy. The doctrine, developed by MONTESQUIEU in his "The Spirit of the Laws" (1748), holds that the LEGISLATIVE, EXECUTIVE, and JUDICIAL functions of government should be vested in separate organs to prevent concentration of power and tyranny. Montesquieu famously wrote: "There can be no liberty where the legislative and executive powers are united in the same person, or in the same body of magistrates. Were the power of judging joined with the legislative, the life and liberty of the subject would be exposed to arbitrary control." This principle was central to the design of the US Constitution (1787) and influenced constitutions worldwide. INDIAN APPLICATION: India follows a MODIFIED separation of powers — strict separation is impossible in a parliamentary system where the executive (Council of Ministers) is drawn from and accountable to the legislature (Parliament). However, the JUDICIARY is fully independent and separate, and the principle of CHECKS AND BALANCES is maintained. The Supreme Court in INDIRA NEHRU GANDHI v RAJ NARAIN (1975) and SP SAMPATH KUMAR v UNION OF INDIA (1987) recognized "separation of powers" as part of the BASIC STRUCTURE of the Constitution, immune from constitutional amendment. (a) "COMMITTED JUDICIARY" — INCORRECT and dangerous. A judiciary "committed" to a particular ideology or government would not be impartial, undermining its role as protector of rights. The phrase "committed judiciary" was infamously used during Indira Gandhi's emergency era (1975-77), and is now a derogatory term. The opposite — INDEPENDENT judiciary — safeguards liberty. (b) Centralization of powers — opposite of safeguarding liberty; concentration of power threatens liberty (Lord Acton: "Power tends to corrupt; absolute power corrupts absolutely"). (c) Elected government — Necessary but not sufficient; even elected governments can become tyrannical (the "tyranny of the majority"). UPSC 2021 official answer: D.

Statement 1 is correct; statement 2 is incorrect. (1) RETIRED JUDGES CALLED BACK — CORRECT. Article 128 of the Constitution provides that the CHIEF JUSTICE OF INDIA may, at any time, with the PREVIOUS CONSENT OF THE PRESIDENT, request any person who has held the office of a Judge of the Supreme Court (or held the office of a Judge of the Federal Court before independence, or has held the office of a Judge of a High Court duly qualified for appointment as a Judge of the Supreme Court) to sit and act as a Judge of the Supreme Court. The retired judge so called back enjoys all the jurisdiction, powers, and privileges of a Supreme Court Judge but is not deemed to be a Supreme Court Judge for other purposes. THE CONSENT REQUIREMENTS: (a) Consent of the retired judge concerned, AND (b) Previous consent (permission) of the President of India. Statement 1 captures this provision accurately. CORRECT. (2) HIGH COURT REVIEW POWER — INCORRECT. The Supreme Court has explicit POWER OF REVIEW under Article 137 of the Constitution: "Subject to the provisions of any law made by Parliament or any rules made under article 145, the Supreme Court shall have power to review any judgment pronounced or order made by it." This is a constitutional grant. However, HIGH COURTS DO NOT have a similar EXPLICIT constitutional power of review. The High Court's power to review is derived from Section 114 of the Code of Civil Procedure (CPC) and Order 47 of the CPC for civil cases — a STATUTORY power, not constitutional. So while High Courts CAN review their judgments in some circumstances, it is not "as the Supreme Court does" — the Supreme Court has a constitutional and broader power, while High Courts have only a statutory and limited power. The asymmetry is significant. INCORRECT. Hence only statement 1 — Option A. UPSC 2021 official answer: A.

Credit rating agencies in India are regulated by SEBI (Securities and Exchange Board of India) under the SEBI (Credit Rating Agencies) Regulations, 1999 — not by RBI — making Statement 1 incorrect. ICRA Limited (formerly Investment Information and Credit Rating Agency of India) is a public limited company listed on both BSE and NSE, making Statement 2 correct. Brickwork Ratings India Pvt. Ltd. is a registered credit rating agency in India, established in 2007 and promoted by Canara Bank, and is registered with SEBI — making Statement 3 correct. Currently, there are seven SEBI-registered credit rating agencies in India: CRISIL, ICRA, CARE, India Ratings, Brickwork, SMERA, and Infomerics. The distinction between SEBI regulation (capital market instruments) and RBI oversight (banks) is a commonly tested UPSC point.

The money multiplier (m) = 1 / reserve ratio (r); as CRR decreases, the reserve ratio falls, making the multiplier larger — banks can lend a greater multiple of their reserves, expanding broad money (M3) — Statement 1 is correct. Statement 2 has the ratio inverted: the money multiplier = Broad Money (M3) / Reserve Money (M0 or High-powered money), not the other way around — Statement 2 is incorrect as stated. Reserve Money (M0) is the RBI's balance sheet liability (currency in circulation + bank reserves with RBI); Broad Money (M3) includes M0 plus bank deposits. The credit multiplier mechanism is how central banks amplify or contract liquidity through reserve requirements. India's money multiplier has generally ranged between 5-6 in recent years, meaning every ₹1 of reserve money supports approximately ₹5-6 of broad money. UPSC 2021 tested this conceptual distinction about the direction of the ratio.

Statement 1 is incorrect: PM-KISAN (Pradhan Mantri Kisan Samman Nidhi) was initially restricted to small and marginal landholding farmers (up to 2 hectares) when launched on 24 February 2019, but was universalised in June 2019 to cover all landholding farmer families irrespective of the size of their landholding, reaching approximately 14.5 crore farmers. Statement 2 is correct: ₹6,000 per year is provided in three equal instalments of ₹2,000 each, transferred directly to the bank accounts of beneficiary farmers through DBT (Direct Benefit Transfer). The scheme is fully funded by the Central Government. Exclusion categories include income-tax payers, government employees, professionals, and constitutional post holders. PM-KISAN is a significant agricultural income support programme; as of 2026, multiple instalments have been released. The scheme tests whether UPSC candidates know the June 2019 universalisation revision. Hence 2 only.

The Global Financial Stability Report (GFSR) is published twice yearly by the IMF, providing comprehensive analysis of global financial markets, systemic risks, and vulnerabilities — Statement 1 is correct. The World Employment and Social Outlook (WESO) report is published by the International Labour Organization (ILO), covering global employment trends, wages, working conditions, and social protection — Statement 2 is correct. The World Economic Outlook (WEO) is published twice yearly by the IMF (not the WTO) — Statement 3 is incorrect; the WTO publishes the World Trade Report and Global Trade Statistics, not the WEO. This question tests candidates' knowledge of which international organisation publishes which flagship report — a commonly examined but frequently confused area in UPSC. The IMF publishes GFSR, WEO, and Fiscal Monitor; the ILO publishes WESO; and the WTO publishes trade-specific reports. Hence 1 and 2 only.

All three statements are correct. The Brahmani is formed by the confluence of the South Koel and Sankh rivers near Rourkela in Jharkhand/Odisha; it flows southeast through Odisha and drains into the Bay of Bengal near Paradip. The Nagavali (sometimes confused with Vamsadhara) originates in the Eastern Ghats in Kalahandi district of Odisha and flows through Andhra Pradesh. The Subarnarekha rises from the Ranchi Plateau — a part of the Chota Nagpur Plateau in Jharkhand — and flows through Jharkhand and West Bengal before emptying into the Bay of Bengal near Sagar Island. All three are east-flowing peninsular rivers that drain into the Bay of Bengal.

This description uniquely fits tropical rainforests. The two defining characteristics cited — rapid decomposition of leaf litter (due to consistently high temperatures and humidity, leaving almost bare soil as nutrients are quickly recycled into the canopy) and a preponderance of epiphytes and lianas (climbers) rather than ground-level understorey plants — are hallmarks of tropical rainforests. The intense competition for sunlight drives plants to evolve as epiphytes (orchids, ferns, bromeliads growing on tree branches) or climbing lianas rather than independent ground plants. Coniferous forests have very slow decomposition due to cold temperatures; dry deciduous forests have seasonal leaf fall and are not epiphyte-rich; mangrove forests are dominated by salt-tolerant halophytes adapted to tidal conditions, not canopy competition.

Talcher (Odisha) is one of India's largest thermal (coal-based) power stations operated by NTPC — it is not a nuclear plant. India's operational nuclear power plants (operated by Nuclear Power Corporation of India Limited, NPCIL) include: Tarapur Atomic Power Station (Maharashtra, India's first and oldest NPP, 1969), Rawatbhata (Rajasthan), Kalpakkam (Tamil Nadu, including the upcoming PFBR fast breeder reactor), Narora (Uttar Pradesh), Kakrapar (Gujarat), Kaiga (Karnataka), Kudankulam (Tamil Nadu, built with Russian technology, largest capacity), and Gorakhpur (Haryana, under construction). India's nuclear power capacity is part of its three-stage nuclear programme designed to eventually use thorium, of which India has vast reserves.

Dholavira (Gujarat) is famous for its sophisticated water harvesting system consisting of a series of reservoirs — at least 16 — connected by channels, and dams to collect rainwater from two seasonal streams. This elaborate system of water management is unique among all known Harappan sites and reflects advanced urban planning.

In the Mughal administrative system, the smallest unit was the village, then the Paragana (a group of villages), then the Sarkar (a group of Paraganas, equivalent to a district), and the largest was the Suba (a province). The Mughal Empire was divided into 15 Subas under Akbar, later expanded to 21 by Aurangzeb.

The Quit India Resolution was passed by the All India Congress Committee (AICC) on 8 August 1942 at the Gowalia Tank Maidan in Bombay (Mumbai). Mahatma Gandhi gave his famous "Do or Die" speech on the same day. The next morning (9 August 1942), the British government arrested the entire Congress leadership, triggering a spontaneous mass uprising across India.

Bethune College (originally Calcutta Female School) was founded by John Elliot Drinkwater Bethune in 1849. Ishwar Chandra Vidyasagar was its first Secretary and played a crucial role in its early management and survival after Bethune's death in 1851. The school became the first institution in Asia to provide higher education for women and was later affiliated as Bethune College.

Shah Nawaz Khan, Prem Kumar Sehgal, and Gurbaksh Singh Dhillon were the three officers of the Indian National Army (Azad Hind Fauj) tried at the famous Red Fort Trials (1945–46). The INA was formed by Subhas Chandra Bose to fight for Indian independence during World War II. Their trial united Indians across political lines and severely dented British prestige. The defence counsel included Bhulabhai Desai and Jawaharlal Nehru.

Manipuri Sankirtana is a combined song and dance performance from Manipur that narrates the life and deeds of Lord Krishna and his consort Radha. It is typically performed during festivals, life-cycle rituals, and other important events. The main musical instrument is the pung (barrel drum) along with cymbals, though other instruments may also be used. It was inscribed on UNESCO's Representative List of Intangible Cultural Heritage in 2013.

The Ajanta Caves are carved into a horseshoe-shaped gorge of the Waghora River in Aurangabad district, Maharashtra. This is the only correctly matched option. The Sanchi Stupa is in Madhya Pradesh on a hill, not near the Chambal. Pandavlena (Nashik) caves are near the Godavari/Darna river region. Amaravati Stupa is on the banks of the Krishna River in Andhra Pradesh, not the Godavari.

Dholavira (in the Kutch district of Gujarat) is renowned for its sophisticated water management system — it had 16 large reservoirs, dams, and a network of drainage channels to harvest rainwater in the otherwise arid landscape. It is one of the largest Harappan sites in India and features a three-tiered town plan suggesting social stratification. The Indus script remains undeciphered. Dholavira was inscribed as a UNESCO World Heritage Site in 2021.

Statement 1 is incorrect: Burzahom (Neolithic site in Kashmir) is known for pit dwellings and hunter-gatherer culture, not rock-cut shrines — rock-cut shrines are associated with sites like Udayagiri. Statement 2 is correct: Chandraketugarh (West Bengal) is famous for its rich terracotta figurines and art tradition. Statement 3 is correct: Ganeshwar (Rajasthan) is a Chalcolithic site known for its large collection of copper artefacts including arrowheads and fishhooks, which points to an early copper-using culture predating the Harappan period.

The Mughal Empire was divided into Subas (provinces) — there were 15 under Akbar and 21 under Aurangzeb. Each Suba was divided into Sarkars (districts), and each Sarkar into Paraganas (sub-districts or groups of villages). So the ascending order from smallest to largest was: Mahal/Village → Paragana → Sarkar → Suba. The Suba was headed by a Subedar (or Sipahsalar), the Sarkar by a Faujdar, and the Paragana by a Shiqdar.

Statement 1 is correct: The Nawabs of Arcot (Carnatic) were originally appointed as subedars under the Nizamat of Hyderabad, which itself emerged from the Mughal Deccan subah — making this lineage traceable to the Mughal provincial system. Statement 2 is correct: The Wadiyar dynasty of Mysore was a feudatory of the Vijayanagara Empire; after Vijayanagara's collapse post-Talikota (1565), Mysore emerged as an independent successor state. Statement 3 is incorrect: Rohilkhand was carved out by Rohilla Afghan chiefs who migrated to India independently and established control over the Gangetic plain; it was not a direct successor to Ahmad Shah Durrani's territories.

Statement 1 is correct: The Chausath Yogini Temple (64 Yoginis Temple) at Mitaoli near Morena (Madhya Pradesh) was built by the Kachchhapaghata king Devapala; an inscription dated to 1323 Vikram Samvat (around 1067 CE) confirms this. Statement 2 is incorrect: There is another circular Yogini temple near Jabalpur (Madhya Pradesh), so this is not the only circular temple in India. Statement 3 is incorrect: The temple is dedicated to Yoginis (female tantric divinities associated with Shaivism), not to Vaishnavism. Statement 4 is correct: The circular plan with a central hall surrounded by a colonnade of shrine cells is widely believed to have inspired Sir Edwin Lutyens's design for the Indian Parliament building.

Blue carbon refers to the carbon captured and stored by the world's oceans and coastal ecosystems — primarily mangroves, tidal salt marshes, and seagrass meadows. These "blue carbon ecosystems" sequester carbon at rates 10–50 times greater per unit area than terrestrial forests and can store it for millennia in their biomass and water-logged soils. The term was formally introduced by the IUCN in 2009. Despite covering a small fraction of the ocean surface, they contribute significantly to global carbon sequestration; for example, mangroves store up to 1,000 tonnes of carbon per hectare. Disturbing these ecosystems releases stored carbon, making their conservation and restoration a key climate change mitigation strategy under REDD+ and the Blue Carbon Initiative (a partnership of IUCN, CI, and IOC-UNESCO). India's Sundarbans mangroves alone are estimated to sequester millions of tonnes of CO₂ annually.

Statements 1 and 2 are correct for India's original INDC/NDC (2015). India committed to: (a) reduce emissions intensity of GDP by 33–35% from 2005 levels by 2030; (b) achieve approximately 40% cumulative installed electric power capacity from non-fossil fuel-based energy resources by 2030; and (c) create an additional carbon sink of 2.5–3 billion tonnes of CO₂ equivalent through additional forest and tree cover by 2030. Statement 3 is incorrect: India's net-zero target is 2070, announced by Prime Minister Modi at COP26 (Glasgow, November 2021) — not 2030. In its updated NDC (August 2022), India enhanced its targets: 45% reduction in emissions intensity (from 33–35%) and 50% non-fossil electricity capacity by 2030 (from 40%). India's net-zero 2070 target is 20 years later than China's 2060 and 30 years later than the EU's 2050.

A keystone species is one that has a disproportionately large effect on its ecosystem relative to its abundance or biomass — remove it and the ecosystem changes dramatically in structure and diversity. The concept was introduced by Robert Paine in 1969 based on his experiments removing sea stars (Pisaster ochraceus) from rocky intertidal zones, which led to mussel dominance and loss of 20+ other species. Examples include: sea otters (controlling sea urchin populations that otherwise overgraze kelp forests), African elephants (creating waterholes used by other species and dispersing seeds over large distances), and tigers in India (regulating herbivore populations, thereby protecting vegetation). Keystone species are not necessarily apex predators (some are plants — e.g., strangler figs — or mutualists), and they are not defined by abundance (Option 1) or endemism (Option 4 — which describes endemic species). This concept is central to UPSC environment questions on biodiversity conservation strategy.

All three statements are correct. The Glasgow Climate Pact (COP26, November 2021) was historically significant for explicitly referencing fossil fuels in COP decision text for the first time: it called for "phasing down" unabated coal power and phasing out "inefficient" fossil fuel subsidies. The wording was weakened from "phase out" to "phase down" at India and China's request — making India's role in this change a frequently tested UPSC exam fact. Prime Minister Modi announced India's "Panchamrit" goals at COP26, including achieving net-zero carbon emissions by 2070. The Glasgow Leaders' Declaration on Forests and Land Use — a parallel political pledge (not part of the formal Pact) signed by over 130 countries representing 90% of global forests — pledged to halt and reverse deforestation and land degradation by 2030 with $19.2 billion in public and private funding. All three elements (coal phase-down, India net-zero, deforestation pledge) are standard COP26 knowledge points for UPSC.

Statement 1 is correct — mitochondrial replacement therapy (MRT) can be performed before fertilisation (maternal spindle transfer) or after fertilisation (pronuclear transfer) to substitute defective mitochondrial DNA with that of a healthy donor, preventing transmission of mitochondrial diseases. Statement 2 is incorrect — while it is true that children predominantly inherit mitochondria from their mother (since the egg contributes almost all cytoplasmic organelles), some studies have found rare paternal mitochondrial inheritance; hence the absolute claim "entirely from mother and not from father" is scientifically contested. The official UPSC key held only Statement 1 as correct.

Statement 1 is correct — restriction endonucleases are molecular scissors that recognise and cleave DNA at specific palindromic sequences (restriction sites), generating sticky or blunt ends. Statement 2 is incorrect — plasmids are extrachromosomal circular DNA molecules that occur naturally in bacteria (and some yeasts), not in animal cells; they are widely used as cloning vectors in rDNA technology. Statement 3 is correct — human insulin (Humulin) has been commercially produced since 1982 by inserting the human insulin gene into Escherichia coli and Saccharomyces cerevisiae — the first recombinant drug approved for human use.

Option D is CORRECT. ACE2 stands for ANGIOTENSIN-CONVERTING ENZYME 2, a membrane-bound enzyme found on the surface of cells in the lungs, heart, kidneys, intestines, and blood vessels. It became GLOBALLY FAMOUS in 2020 because the SARS-CoV-2 virus (which causes COVID-19) uses ACE2 as its CELLULAR ENTRY RECEPTOR — the spike (S) protein of the virus binds to ACE2 on host cells, allowing the virus to fuse with and enter the cell. The same ACE2 receptor was also used by the original SARS-CoV virus (2003 outbreak). NORMAL FUNCTION OF ACE2: It is part of the renin-angiotensin-aldosterone system (RAAS) which regulates blood pressure. ACE2 converts angiotensin II (a vasoconstrictor) into angiotensin (1-7), which is a vasodilator. So ACE2 normally LOWERS blood pressure and protects against organ damage. WHY THE QUESTION MATTERS: The 2021 UPSC Prelims was held in October 2021, in the middle of the COVID-19 pandemic — ACE2 was constantly in news as researchers worldwide worked to understand viral entry mechanisms, develop vaccines, and design ACE2-based therapies. (a) WRONG — refers to transgenes like cry1Ac. (b) WRONG — that's NavIC/IRNSS. (c) WRONG — radio collars use VHF/UHF/GPS, not ACE2. UPSC 2021 official answer: D.

Option B is CORRECT. BOLLGARD I and BOLLGARD II are commercial trade names for GENETICALLY MODIFIED COTTON technologies developed by Monsanto (now Bayer) that confer resistance to bollworm pests. BOLLGARD I (introduced in India in 2002, the first GM crop ever approved for commercial cultivation in India) contains the cry1Ac gene from the soil bacterium Bacillus thuringiensis (Bt), which produces a protein toxic to lepidopteran pests, particularly the AMERICAN BOLLWORM (Helicoverpa armigera). BOLLGARD II (approved in India in 2006) contains TWO Bt genes — cry1Ac AND cry2Ab — providing broader-spectrum protection against multiple bollworm species (American bollworm, pink bollworm, spotted bollworm) and reducing the risk of resistance development. IMPACT IN INDIA: Bt cotton transformed Indian cotton cultivation — by 2014, over 90% of India's cotton acreage was under Bt varieties. India became the world's largest cotton producer. However, after 2015, the PINK BOLLWORM developed resistance to Bollgard II, raising concerns about the durability of the technology and the need for refuge crops, integrated pest management, and possibly Bollgard III. CONTROVERSIES: Royalty fees, farmer suicides, seed price regulation under the Cotton Seed Price Control Order. Cotton remains the only GM crop commercially approved in India; Bt-brinjal and HT mustard remain under moratorium/litigation. UPSC 2021 official answer: B.

Option B is CORRECT. BISPHENOL A (BPA) is an industrial chemical used as a key monomer in the manufacture of POLYCARBONATE plastics and EPOXY RESINS. Polycarbonate is a transparent, shatter-resistant, lightweight plastic widely used in baby bottles, water bottles, food storage containers, eyewear lenses, CDs and DVDs, and the lining of metal food and beverage cans (epoxy resin coatings). HEALTH CONCERN: BPA is an ENDOCRINE DISRUPTOR — it mimics the hormone ESTROGEN and can interfere with the endocrine system at very low doses. Studies have linked BPA exposure to: hormonal imbalances, reproductive disorders, developmental issues in children, increased risk of obesity, type-2 diabetes, cardiovascular disease, and certain cancers. Particularly worrying is leaching of BPA into food/drink, especially when polycarbonate is heated (microwave, dishwasher) or when contents are acidic. REGULATORY ACTIONS: The European Union banned BPA in baby bottles in 2011; France banned it in all food contact materials in 2015. The US FDA banned BPA in baby bottles, sippy cups, and infant formula packaging. India's FSSAI banned BPA in polycarbonate baby bottles in 2014. BPA-FREE alternatives include polypropylene (PP), tritan, and glass. (a) LDPE — used for plastic bags, squeeze bottles; doesn't contain BPA. (c) PET — used for water/soda bottles; doesn't contain BPA. (d) PVC — pipes, flooring; doesn't contain BPA (but has its own concerns with plasticisers). UPSC 2021 official answer: B.

Both statements are CORRECT — Option C. Statement 1 is CORRECT. RECOMBINANT VECTOR VACCINES are produced using GENETIC ENGINEERING. Scientists insert a gene encoding the antigen (immunogenic protein) of a pathogen (e.g., spike protein of SARS-CoV-2) into a harmless carrier organism (the "vector"). When the vector is introduced into the body, host cells take up the gene and produce the antigen, triggering an immune response WITHOUT exposing the person to the actual pathogen. Statement 2 is CORRECT. The vectors used can be either VIRUSES (e.g., adenoviruses, vesicular stomatitis virus, modified vaccinia Ankara) or BACTERIA (e.g., attenuated Salmonella, Mycobacterium bovis BCG). EXAMPLES IN COVID-19 PANDEMIC: The OXFORD-ASTRAZENECA / Covishield vaccine (manufactured in India by Serum Institute) uses a modified chimpanzee adenovirus (ChAdOx1) carrying the SARS-CoV-2 spike protein gene — a textbook example of a recombinant viral vector vaccine. The Russian SPUTNIK V vaccine uses two different human adenovirus vectors (Ad26 and Ad5). Johnson & Johnson's Janssen vaccine uses Ad26. The Ebola vaccine (ERVEBO) uses VSV (vesicular stomatitis virus) as a vector. ADVANTAGES: Strong immune response, do not require complex cold-chain (compared to mRNA vaccines), can be developed rapidly. CHALLENGES: Pre-existing immunity to the vector can reduce effectiveness; rare clotting side effects with adenovirus vectors. UPSC 2021 official answer: C.

Statements 2 and 3 are correct. Statement 1 is incorrect: it is the International Seabed Authority (ISA), established under UNCLOS, that regulates seabed mining in international waters (the "Area") — not the Global Ocean Commission, which is an independent policy body. Statement 2 is correct: India holds ISA exploration contracts for polymetallic nodules in the Central Indian Ocean Basin and for polymetallic sulphides in the Indian Ocean. Statement 3 is correct: rare earth elements, cobalt, manganese, and nickel-rich polymetallic nodules exist on the seafloor in international waters.

Only Statement 2 is correct. Statement 1 is incorrect: the International Mother Language Day (21 February) was proclaimed by UNESCO — not UNICEF — in November 1999, effective from 2000, to promote linguistic diversity. It commemorates the 1952 Dhaka student protests where students were killed demanding Bangla as a state language of Pakistan. Statement 2 is correct: the demand for Bangla as an official national language of Pakistan was indeed raised in Pakistan's Constituent Assembly in 1948, notably by Dhirendranath Datta.

Statements 1 and 3 are correct. WaterCredit is an initiative of Water.org, the non-profit co-founded by Matt Damon and Gary White — it is not a WHO or World Bank programme, making statement 2 incorrect. WaterCredit was the first initiative to systematically apply microfinance tools to the water and sanitation sector (WASH), enabling poor households to access small loans to build toilets and piped water connections rather than depending on charity or subsidies. The goal (statement 3) is to foster financial independence for the poor in meeting their water needs — a market-based complement to traditional subsidy approaches.

Statements 2 and 3 are correct. Statement 1 is incorrect: EPF coverage under the Employees' Provident Funds and Miscellaneous Provisions Act, 1952 applies to establishments employing 20 or more persons — casual workers in smaller establishments or earning below the wage ceiling are not automatically covered. Statement 2 is correct: the Minimum Wages Act, 1948 (now subsumed under the Code on Wages, 2019) guarantees regular working hours and overtime payment to all workers including casual and contract workers, irrespective of establishment size. Statement 3 is correct: the Payment of Wages (Amendment) Act empowered the government to notify that a specific industry or establishment shall pay wages only through bank accounts, which has been done to ensure financial inclusion and prevent wage theft.

Halbi, Ho, and Kui are all tribal languages spoken in central and eastern India. Halbi (also called Bastari) is an Eastern Indo-Aryan language spoken by communities across Bastar (Chhattisgarh) and adjacent areas, written in Devanagari and Odia scripts. Ho is an Austroasiatic (Munda family) language written in the Warang Chiti script, spoken by about 10 lakh tribal people in Odisha and Jharkhand. Kui is a South-Eastern Dravidian language spoken by the Kondh (Kandha) tribal community primarily in Odisha. All three are listed as scheduled languages or tribal languages of significant anthropological importance.

Only statement 2 is correct. The Montagu-Chelmsford Reforms (Government of India Act, 1919) did not grant universal voting rights to all women above 21 — the franchise was highly restricted and property/education based. Statement 1 is therefore incorrect. Statement 2 is correct: the Government of India Act, 1935 extended the principle of separate representation and reserved seats to women (alongside depressed classes and workers), significantly expanding women's formal political participation in provincial legislatures. Women's suffrage was made universal in independent India only with the Constitution of 1950.

Statements 1 and 3 are correct. FATF was established at the G7 Summit in Paris in 1989 to set standards and promote implementation of measures against money laundering and terrorist financing. India has been a full member of FATF since 2010. Statement 2 is incorrect: countries on the FATF Grey List (Jurisdictions under Increased Monitoring) are not subject to direct financial sanctions. Grey listing means they are subject to increased monitoring and must commit to an action plan. Direct countermeasures are reserved for countries on the Black List (call to action list).

Statements 1 and 2 are correct. The ITPA, 1956 is the principal legislation on sex trafficking in India. The NIA Amendment Act, 2019 significantly expanded NIA's jurisdiction to include human trafficking as an "offence affecting the sovereignty, security and integrity of India," allowing the NIA to investigate such cases. Statement 3 is incorrect: India has generally been classified as a Tier-2 or Tier-2 Watch List country in the US TIP Report, meaning the government does not fully meet minimum standards for the elimination of trafficking but is making significant efforts. Tier-1 status is reserved for countries that fully meet the TVPA's minimum standards.

Statement 1 is correct: mitochondria contain their own circular DNA (mitochondrial DNA or mtDNA) and 70S ribosomes — strong evidence for the endosymbiotic theory (proposed by Lynn Margulis) that mitochondria evolved from free-living bacteria engulfed by ancestral eukaryotic cells; mitochondrial DNA encodes 37 genes including 13 proteins of the oxidative phosphorylation machinery. Statement 2 is correct: mitochondria are exclusively maternally inherited because fertilisation is achieved almost entirely by the egg cell's cytoplasm (which contains thousands of mitochondria), while sperm mitochondria are typically destroyed after fertilisation; therefore, mitochondrial diseases and mtDNA mutations are transmitted from mothers to all their children. Statement 3 is incorrect: mitochondria are found in virtually all eukaryotic cells, including both plant and animal cells — plant cells have both mitochondria (for respiration) and chloroplasts (for photosynthesis); the idea that plants lack mitochondria is a common misconception. The correct answer is 1 and 2 only (option A).

Statement 1 is correct: vaccines prime the adaptive immune system by presenting antigens (whole pathogens, pathogen components, or instructions to make them) in a controlled manner, triggering production of antibodies and immunological memory without causing the disease itself — the immune system then "remembers" the pathogen and can mount a rapid protective response upon real exposure. Statement 2 is correct: mRNA vaccines (like the Pfizer-BioNTech and Moderna COVID-19 vaccines) deliver synthetic mRNA instructions encoding a specific pathogen protein (e.g., SARS-CoV-2 spike protein) into host cells; cells translate the mRNA to produce the protein, which the immune system recognises as foreign and mounts a protective response — the mRNA itself is rapidly degraded and does not interact with the host DNA. Statement 3 is incorrect: live attenuated vaccines contain weakened (attenuated), not killed, forms of the pathogen (e.g., OPV for polio, MMR for measles-mumps-rubella, BCG for tuberculosis); killed/inactivated vaccines (e.g., IPV, Covaxin) contain dead pathogens — these are two different and distinct vaccine types. Hence 1 and 2 only (option A).

Statement 1 is correct: stainless steel is an alloy with iron (Fe) as the base metal, containing a minimum of 10.5% chromium by mass; many grades (austenitic stainless steels like the popular 304 and 316 grades) also contain significant amounts of nickel (8-12%) to stabilise the face-centred cubic crystal structure and improve ductility and corrosion resistance. Statement 2 is correct: the key to stainless steel's corrosion resistance is chromium, which reacts with atmospheric oxygen to form a thin, self-repairing passive oxide layer (Cr₂O₃) on the surface — this "passive film" is only a few nanometres thick but acts as a barrier against further oxidation and rust, unlike ordinary iron/carbon steel which oxidises progressively. Statement 3 is incorrect: stainless steel is definitively an alloy (a mixture of metals and sometimes non-metals), not a pure metal; pure iron is soft and highly reactive, while stainless steel's useful properties derive from its alloyed composition. Uses include kitchenware, surgical instruments, chemical reactors, construction, and food processing equipment. Hence 1 and 2 only (option A).

OneWeb is a UK-based global satellite communications company (now owned by Eutelsat) that operates a Low Earth Orbit (LEO) satellite constellation designed to provide high-speed broadband internet connectivity worldwide, particularly to underserved and remote areas beyond the reach of terrestrial fibre infrastructure. ISRO (through its commercial arm NewSpace India Limited, NSIL) signed agreements to launch OneWeb satellites using GSLV Mk-III/LVM3 rockets — a significant commercial space launch contract that demonstrated India's growing competitiveness in the global satellite launch market; India launched 36 OneWeb satellites on LVM3-M2 in October 2022 and another 36 on LVM3-M3 in March 2023. OneWeb's constellation operates at approximately 1,200 km altitude providing low-latency internet; services target governments, enterprises, and rural connectivity programmes. The partnership has no connection to weather monitoring (option B — ISRO has its own INSAT/IRNSS systems for that), navigation services (option C — NavIC serves that purpose), or planetary missions (option D). This question tests awareness of commercial space launch partnerships as a component of India's space economy strategy.

Statement 1 is correct: malaria is caused by Plasmodium species (protozoan parasite — P. falciparum, P. vivax, P. malariae, P. ovale) and is transmitted exclusively by the bite of infected female Anopheles mosquitoes, which transmit the parasite during blood meals; only female mosquitoes bite as they require blood for egg development. Statement 2 is incorrect: dengue is caused by the dengue virus (DENV, a flavivirus with four serotypes — DENV 1-4), NOT by a bacterium; it is transmitted by Aedes aegypti (primary vector) and Aedes albopictus mosquitoes — this is a critical factual error in the stem that makes statement 2 wrong. Statement 3 is correct: lymphatic filariasis (elephantiasis) is caused by Wuchereria bancrofti (and Brugia malayi/timori) — filarial nematode worms — and is transmitted by Culex mosquitoes in urban and semi-urban areas; the worms obstruct lymphatic vessels causing accumulation of lymph fluid and massive swelling of limbs (lymphoedema). India runs the National Programme for Elimination of Lymphatic Filariasis. Hence 1 and 3 only (option A).

Statement 1 is correct: plant cells (and also fungi, bacteria, and archaea) have a rigid cell wall external to the plasma membrane; in plants, the primary cell wall is composed of cellulose fibres embedded in a matrix of hemicellulose and pectin, providing structural support, shape maintenance, and protection; animal cells completely lack a cell wall. Statement 2 is correct: both plant and animal (and all other eukaryotic) cells are bounded by a plasma membrane (cell membrane) — a phospholipid bilayer with embedded proteins that controls the passage of substances in and out of the cell and is essential for maintaining cellular homeostasis. Statement 3 is incorrect: this statement has it backwards — plant cells (not animal cells) typically possess one large central vacuole that can occupy up to 90% of the cell volume, storing water, ions, pigments, and waste products, and maintaining turgor pressure; animal cells may have small, transient vacuoles but lack the large permanent central vacuole that is a defining feature of mature plant cells. Hence 1 and 2 only (option A). Cell biology distinctions between plant and animal cells are standard UPSC biology content.

All three statements about Agni-V are correct. Agni-V is classified as India's first ICBM-class (Intercontinental Ballistic Missile) surface-to-surface ballistic missile; while India officially describes it as a "long-range" missile for diplomatic reasons, its range well exceeds the 5,500 km ICBM threshold — statement 1 is correct. Agni-V has a confirmed minimum range of 5,400 km with reports of capability up to 7,000+ km, placing Beijing, Shanghai, and most of Europe within range; on 11 March 2024 (Mission Divyastra), India successfully tested Agni-V with MIRV (Multiple Independently targetable Re-entry Vehicles) technology, making India the sixth country to possess MIRV-capable missiles — statement 2 is correct. Agni-V uses solid propellant (HTPB-based) in all three of its stages, unlike liquid-fuel rockets which require time-consuming fuelling before launch; the solid-fuel design makes it canisterised and road-mobile, allowing rapid deployment and significantly reducing launch preparation time — statement 3 is correct. All three statements are accurate based on official DRDO and government sources.

All three statements correctly identify key improvements in the Sendai Framework over the Hyogo Framework. The Sendai Framework broadens scope to include technological hazards (like industrial accidents, nuclear incidents) and environmental hazards, beyond the primarily natural hazard focus of HFA. The shift from "disaster management" to "disaster risk management" is a conceptual advancement — focusing on reducing underlying risk rather than only responding to disasters. The Sendai Framework also introduces specific, measurable, time-bound global targets and outcome indicators (seven targets, 38 indicators) that were absent in HFA, making accountability much clearer.

All three statements are conceptually correct and reflect the standard disaster risk framework. The risk formula — Risk = Hazard × Vulnerability / Coping Capacity — is a foundational concept in disaster risk management (simplified as Risk = Hazard × Vulnerability in basic formulations). Vulnerability encompasses physical, social, economic, and environmental factors that make communities susceptible to harm. The third statement correctly identifies that coping capacity (resilience) is a modifier — even a highly hazard-exposed community with strong infrastructure, institutions, and preparedness can have lower effective disaster risk than a less exposed but highly vulnerable community.

All three statements are correct. NIDM was upgraded from the National Centre for Disaster Management (NCDM) in 2003 and was subsequently given a statutory mandate under Section 42 of the Disaster Management Act, 2005. It serves as the apex centre for training, capacity development, research, documentation, and policy advocacy in disaster management. NIDM functions under the Ministry of Home Affairs (MHA). Its mandate includes integrating DRR into educational curricula, which aligns with the Sendai Framework's priority on understanding disaster risk.