💥Join UPSC 2027,2028 Mentorship (July Batch) + XFactor Notes & Microthemes PDF

GS Paper: GS3-15.Science and Technology- Developments and their Applications and Effects in Everyday Life.

  • The Nobel Prize in Physics of 2014 was jointly awarded to Akasaki, Amano and Nakamura for the invention of Blue LEDs in 1990s. How has this invention impacted the everyday life of human beings?

    The Blue LEDs invention triggered a fundamental shift in lighting technology, comparable to the transition from the candle to the incandescent bulb. Without the Blue LED, the world was stuck with energy-inefficient incandescent bulbs and mercury-laden fluorescent lamps.

    Impact on Everyday Life

    Energy Efficiency: LEDs convert 50% of energy to light, compared to just 4% for incandescent bulbs lasting 100,000 hours. This efficiency slashes global CO2 emissions.

    Electronics & Mobility: Provided the essential backlighting for LCD screens in smartphones and laptops, allowing for thinner designs and significantly longer battery life.

    Cost-saving: Eg- 50000 hours of white LEDs cost $86 compared to $350 in incandescent light.

    Democratization of Light: Enabled low-power, solar-powered LED lamps, providing safe and affordable light to over a billion people in off-grid rural areas.

    New innovations: Eg- New screens of mobiles & TV which are more efficient & sustainable.

    Advancements in Healthcare and Sanitation

    Water Purification: UV-light emitting diodes are used to sterilize drinking water by destroying the DNA of bacteria and viruses.

    Medical Treatment: Blue light is used in phototherapy to treat neonatal jaundice and certain skin conditions.

    Sustainable Agriculture (Vertical Farming)

    Blue light is essential for photosynthesis.

    Indoor Farming: By fine-tuning light “recipes” using Blue and Red LEDs, farmers can grow food indoors in urban environments without pesticides, using 90% less water

    Enhanced Communication and Connectivity

    Optical Storage: The development of the blue laser led to Blu-ray technology, allowing for much higher data storage densities than earlier red-laser CDs or DVDs.

    Li-Fi: Current research is using Blue LEDs for Light Fidelity (Li-Fi), a high-speed wireless communication technology that transmits data through light pulses.

    Government initiatives promoting LEDs

    UJALA ( Unnat Jyoti by affordable LED for all)

    Street Lighting National Program (SLNP) as Prakash Rath

    In 2026, as we strive for Net Zero goals, the Blue LED remains our most effective tool for “decarbonizing” the night.

  • What is the basic principle behind vaccine development? How do vaccines work? What approaches were adopted by the Indian vaccine manufacturers to produce COVID-19 vaccines?

    Vaccines are biological preparations that provide immunity against infectious diseases by training the immune system to fight pathogens. India has emerged as a global vaccine hub, supplying over 60% of global vaccine demand through indigenous vaccine development.

    Basic Principle Behind Vaccine Development

    Mimicking natural infection: Vaccines imitate infections to safely activate the body’s immune defenses.

    Antigen as the key component: Vaccines contain antigens that trigger antibody production. These may include:

    Weakened or killed pathogens

    Pathogen fragments or genetic material

    Inactivated bacterial toxins (toxoids)

    Types of vaccine platform:

    Live-attenuated vaccines: Use weakened living pathogens, providing strong immunity but posing risks to immunocompromised individuals. Eg- MMR and Chickenpox vaccines.

    Non-live vaccines: Use killed pathogens or subunits, making them safer but requiring booster doses due to shorter immunity. Eg- DTaP vaccine.

    Addressing viral mutations: Vaccines for rapidly mutating viruses are periodically updated to maintain protection. Eg- Seasonal flu vaccines and COVID-19 boosters.

    How Vaccines Work?

    Immune system activation: Vaccine antigens are recognized as foreign threats, activating white blood cells to multiply and respond.

    Antibody production: White blood cells produce antibodies that specifically identify and neutralize the pathogen.

    Immunological memory: After the antigen is removed, memory cells remain in the body, providing long-term immunity.

    Protection against disease: On future exposure, memory cells rapidly produce antibodies, preventing severe illness or death.

    Approaches Adopted by Indian Vaccine Manufacturers for COVID-19

    Inactivated whole-virion platform (Covaxin): Bharat Biotech and Indian Council of Medical Research developed a vaccine using chemically inactivated SARS-CoV-2 virus to safely trigger immunity.

    Viral vector platform (Covishield): Serum Institute of India(SII) used a harmless chimpanzee adenovirus carrying spike protein genetic code to stimulate immune response.

    Recombinant protein subunit platform (Covovax & Corbevax): SII and Biological E developed vaccines using purified spike proteins with adjuvants to induce antibodies.

    DNA plasmid platform (ZyCoV-D): Zydus Cadila developed the world’s first human DNA vaccine using plasmid DNA delivered through a needle-free injector.

    mRNA platform (GEMCOVAC-19): Gennova Biopharmaceuticals developed an mRNA vaccine using lipid nanoparticles to deliver spike-protein instructions safely into cells.

    India’s diverse COVID-19 vaccine response-from inactivated vaccines to DNA and mRNA platforms-has strengthened its role as the Pharmacy of the World. Expanding indigenous R&D and ensuring timely immunization remain vital for achieving United Nations SDG 3(Good Health and Well-being)

  • Each year a large amount of plant material, cellulose, is deposited on the surface of Planet Earth. What are the natural processes this cellulose undergoes before yielding carbon dioxide, water and other end products?

    Cellulose, the main structural material in plant cell walls, is the Earth’s most abundant organic polymer. When plants die, microorganisms decompose cellulose into carbon dioxide, water, and humus, recycling nutrients back into ecosystems.

    Natural processes undergone by cellulose

    Chemical Degradation:

    Cellulose decomposition is carried out by microbes such as Trichoderma and Clostridium, which secrete cellulase enzymes.

    These enzymes sequentially break cellulose into smaller chains, then cellobiose,and finally glucose for microbial absorption.

    Metabolic Processing: After absorption, microbes metabolize glucose to release energy.

    Oxygen-rich conditions: aerobic microbes convert glucose into carbon dioxide and water.

    Oxygen-poor environments: wetlands, anaerobic microbes and methanogens ferment glucose, producing methane and carbon dioxide.

    Humification:

    Not all plant material fully decomposes; some forms stable humus through reactions with lignin and microbial proteins.

    Humus enriches soil fertility, improves water retention, and acts as an important long-term carbon sink.

    The natural processing of deposited cellulose represents the core operational machinery of the Global Carbon Cycle. Without this systematic microbial and physical breakdown, plant litter would accumulate indefinitely, locking away vital nutrients and choking planetary ecosystems.

  • The world is facing an acute shortage of clean and safe freshwater. What are the alternative technologies which can solve this crisis? Briefly discuss any three such technologies citing their key merits and demerits.

    As per the report of the Global Commission on the Economics of Water, the world’s water systems are under “unprecedented stress” and the demand for fresh water will outstrip supply by 40% by 2030.

    Global freshwater Crisis

    4.4 billion people lack access to safe drinking water

    703 million people have no access to clean drinking water.

    Agriculture consumes 70% of the world’s freshwater

    India

    4% of the world’s freshwater resources

    600 million Indians experience water scarcity. (NITI Aayog)

    By 2030, 700 million people could be displaced due to water shortages (UNICEF, 2025)

    Global water crisis could result in losses of up to $8 trillion over the next 25 years (Global Commission on the Economics of Water, 2024)

    Alternative Technologies That Can Solve the Freshwater Crisis

    Desalination Technologies to convert seawater/brackish water into potable water.

    Wastewater Recycling & Reuse through Membrane Bioreactors (MBR), tertiary treatment and advanced oxidation.

    Atmospheric Water Harvesting using condensation (cooling below dew point).

    Solar Distillation for low-cost, off-grid evaporation-condensation.

    Managed Aquifer Recharge (MAR) using recharge wells, percolation tanks and treated wastewater.

    Fog & Dew Harvesting in coastal and high-elevation areas.

    Smart Irrigation Technologies (drip, soil moisture sensors) to reduce agricultural water demand.

    Precision Leak Detection Systems using IoT to minimise distribution losses.

    Rainwater Harvesting Systems integrated with rooftops, storage tanks and recharge pits.

    Floating Solar + Desal Units for dual energy-water generation.

    Three Technologies With Key Merits and Demerits

    Atmospheric Water Harvesting (AWH) – Eg – Source Hydropanels deployed in Ladakh schools.

    Merits:

    Decentralized, off-grid water access for remote areas.

    No reliance on groundwater or rainfall.

    Scalable from household to community systems.

    Demerits:

    Low yield in low-humidity climates.

    High per-litre cost for advanced AWH systems.

    Requires maintenance of filters/desiccants.

    Wastewater Recycling & Reuse Eg – Singapore’s NEWater, Nagpur’s Bhandewadi recycling plant.

    Merits:

    Reduces pressure on freshwater sources by closing the loop.

    Low energy requirement compared to desalination.

    Ensures year-round supply, even in dry regions.

    Demerits:

    Public resistance to potable reuse (“yuck factor”).

    Risk of contamination if systems are poorly maintained.

    High initial investment for advanced tertiary treatment.

    Desalination using Reverse Osmosis & Thermal DistillationEg – Israel’s Sorek RO plant, India’s Minjur RO plant (Chennai).

    Merits:

    Large and climate-independent supply from oceans.

    Useful for coastal megacities facing groundwater depletion. Eg- Mumbai

    Continuous and reliable output even in droughts.

    Demerits:

    High energy consumption, increasing carbon footprint.

    Brine discharge harms marine ecosystems.

    High capital and operating cost for poorer regions.

    A portfolio approach, not a single technology, will determine long-term water security.

  • What is the technology being employed for electronic toll collection on highways? What are its advantages and limitations? What are the proposed changes that will make this process seamless? Would this transition carry any potential hazards?

    The total length of National Highways in India is around 1.5 Lakh km. India currently uses FASTag, based on RFID (Radio Frequency Identification) technology.

    Passive RFID tagRFID readers

    Advantages of FASTag-Based Electronic Tolling

    Reduced Congestion – Minimises stoppages, reduces queueing, and cuts travel time

    Continuous movement lowers Fuel Consumption & Emissions

    Improved Revenue Realisation- Eliminates leakages, cash handling issues, and human errors.

    Better Traffic Management due to real-time vehicle data – enhances logistics efficiency.

    Digital Financial Inclusion –Promotes cashless payments and creates digital transaction footprint

    Limitations of the Current FASTag System

    RFID Reading Errors- Faulty tags or improper placement cause delays.

    Congestion during peak hours.

    Bank downtime results in payment failures and traffic jams.

    Fraud & Misuse- Cloning of RFID tags, misuse of blacklisted/invalid tags.

    Inadequate adaption – Eg- non availability in rural areas

    Proposed Changes to Make Tolling Seamless

    Expansion of ETC lanes – 100% coverage by 2025

    ANPR (Automatic Number Plate Recognition)-Based Tolling

    GPS-based – Vehicles fitted with GPS devices and toll are charged based on the distance travelled on a highway.

    Free-Flow Tolling (FFT) Corridors – open road tolling for uninterrupted movement.

    Integration with NHAI’s ‘One Vehicle One FASTag’ Drive

    Potential Hazards in Transition to New Tolling Systems

    Privacy & Surveillance Concerns – Eg- Continuous GPS tracking and ANPR imaging

    Cybersecurity Risks- vulnerability to hacking, spoofing, or data breaches.

    ANPR systems may misread plates due to dirt, or damaged plates.

    Digital Divide – Eg- 33% rural population is digitally literate (NFHS-5)

    Technical Failures- Weather, fog, rain etc can affect ANPR accuracy and system reliability.

    Replacing toll plazas with nationwide FFT infrastructure requires massive investment.

    Addressing these concerns can ensure efficient, seamless, congestion-free highways.

  • Advancing Electrolyte Engineering for Durable and Affordable Aqueous Batteries

    Why in the news?

    Scientists at the Institute of Nano Science and Technology (INST), Mohali, under the Department of Science and Technology (DST), have developed a novel electrolyte additive (BDIM) that significantly improves the performance and lifespan of Aqueous Zinc-Ion Batteries (AZIBs).

    Key Highlights

    • AZIBs are emerging as safer, cheaper, and more sustainable alternatives to lithium-ion batteries.
    • Major challenges:
      • Zinc dendrite formation
      • Hydrogen Evolution Reaction (HER)
      • Corrosion of zinc anode
      • Poor cycling stability
    • Researchers developed BDIM (1,3-bis(1,3-dicarboxypropyl)-1H-imidazole-3-ium chloride) as an electrolyte additive.
    • BDIM selectively adsorbs on the zinc surface and occupies the Inner Helmholtz Plane (IHP).
    • It displaces water molecules, thereby:
      • Suppressing hydrogen evolution
      • Reducing corrosion
      • Preventing dendrite growth
      • Enhancing battery life and safety
    • Researchers used: Ultramicroelectrode (UME) and Fast-Scan Cyclic Voltammetry (FSCV)
      to study zinc deposition mechanisms.

    Significance

    • Extends battery lifespan without costly material redesign.
    • Improves safety and reliability of rechargeable batteries.
    • Supports large-scale renewable energy and grid-storage applications.
    • Can reduce maintenance costs of energy-storage infrastructure.

    Prelims Facts

    • AZIB Electrolyte: Water-based, making it non-flammable and safer than lithium-ion batteries.
    • Inner Helmholtz Plane (IHP): Region near the electrode surface where electrochemical reactions occur.
    • Hydrogen Evolution Reaction (HER): Undesirable side reaction that reduces battery efficiency.
  • VYOMA Innovation Challenge

    Why in the news?

    The Digital India BHASHINI Division, under the Ministry of Electronics and Information Technology, launched the VYOMA Innovation Challenge to promote multilingual, voice first, offline AI solutions for India.

    Key Highlights

    • Initiative launched in collaboration with:
      • Current AI
      • Kalpa Impact.
    • Objective:
      • Promote open source multilingual AI systems that can function in:
        • Offline environments
        • Low connectivity regions.

    About Sunno Sutra

    The challenge is based on:

    • Sunno Sutra: A multilingual voice first handheld AI reference device.
    • Developed jointly by: BHASHINI and Current AI.

    Features of Sunno Sutra

    • Supports: Conversational AI in Indian languages.
    • Works: Without cloud dependence.
    • Uses: On device AI capabilities.
    • Suitable for: Rural and low resource environments.

    Objectives of the VYOMA Innovation Challenge

    • Encourage development of:
      • Multilingual AI applications.
      • Voice based technologies.
    • Improve:
      • Digital accessibility.
      • Language inclusion.
    • Promote: Edge AI innovation in India.

    What is Edge AI?

    Edge AI refers to: Artificial Intelligence processing directly on local devices instead of remote cloud servers.

    Advantages:

    • Faster processing
    • Offline functionality
    • Better privacy
    • Reduced internet dependence

    Sectors Targeted

    Potential applications include:

    • Education
    • Agriculture
    • Healthcare
    • Governance
    • Public service delivery

    [2020] With the print state of development, Artificial Intelligence can effectively do which of the following?
    1. Bring down electricity consumption in industrial units
    2. Create meaningful short stories and songs
    3. Disease diagnosis
    4. Text -to -Speech Conversion
    5. Wireless transmission of electrical energy
    Select the correct answer using the code given below:

    [A] 1, 2, 3 and 5 only

    [B] 1, 3 and 4 only

    [C] 2, 4 and 5 only

    [D] 1, 2, 3, 4 and 5

  • Biopharma SHAKTI Scheme: Boosting India’s Biologics & Biosimilars Sector

    Why in the News

    The Government has announced the Biopharma SHAKTI Scheme with an outlay of ₹10,000 crore (5 years) to strengthen India’s biopharmaceutical ecosystem and enhance global competitiveness.

    What is Biopharma SHAKTI?

    • A flagship initiative to:
      • Promote biologics and biosimilars manufacturing
      • Support R&D, clinical trials, and innovation
    • Goal: Make India a global biopharma hub and ensure affordable healthcare

    Key Objectives

    • Build a self-reliant biopharma ecosystem
    • Reduce import dependence
    • Improve global competitiveness
    • Promote innovation-driven manufacturing

    Major Components of the Scheme

    • Funding Support: Discovery Grant Fund and Equity Fund for drug development
    • R&D Ecosystem
      • Strengthening: National Institute of Pharmaceutical Education and Research (NIPER)
      • Creation of a National Biopharma R&D Network
    • Clinical Trials Expansion
      • 1,000 accredited trial sites across India
      • Led by Indian Council of Medical Research (ICMR)
    • Manufacturing Boost
      • Incentives for: Fermentation-based bulk drugs and Biopharma manufacturing inputs
    • Devices & Packaging
      • Develop ecosystem for: Drug delivery devices and Advanced packaging. 
    • Biosimilars & Biologics Production: Biosimilars (cost-effective versions of biologics) and Emerging biologics like gene therapies.
    • Regulatory Strengthening: Strengthen Central Drugs Standard Control Organisation (CDSCO)
      • Create scientific review cadre
      • Faster and globally credible approvals

    What are Biologics & Biosimilars?

    • Biologics: Medicines derived from living organisms (e.g., vaccines, monoclonal antibodies)
    • Biosimilars: Cheaper versions of biologics with similar efficacy
    • Not identical (due to complexity of biologics)
    • Must show no clinically meaningful differences in safety, purity, and effectiveness
    [2025] With reference to monoclonal antibodies, consider the following: 
    1. They are man-made proteins. 
    2. They stimulate the patient’s immune system to fight the specific disease. 
    3. They are produced using animal cells only. 
    Select the correct answer using the code given below: 
    (a) I and II only (b) II and III only (c) I and III only (d) All the three
  • Industrial Hemp

    Why in the News?

    • The Chief Minister of Himachal Pradesh has initiated a policy push to legalise and regulate industrial hemp cultivation.

    What is Industrial Hemp

    • Scientific name: Cannabis sativa L.
    • Belongs to the Cannabis genus and Cannabaceae family
    • Herbaceous, dioecious plant
    • Botanically related to marijuana but very different in use and effects
    • THC content less than 0.3%
    • High fiber content and negligible psychoactive effect

    Industrial Hemp vs Marijuana

    • Marijuana: High tetrahydrocannabinol (THC) and psychoactive
    • Industrial hemp: Extremely low THC, used for industrial and commercial purposes

    Key Characteristics

    • Fast growing crop
    • Environment friendly
    • Requires relatively less water and pesticides
    • Suitable for diversified agro industrial value chains

    Applications of Industrial Hemp

    • Fibre and textiles: Cloth, upholstery, ropes
    • Industrial uses: Auto parts, paper, packaging
    • Energy: Biofuel production from stalk
    • Construction: Building materials like hempcrete
    • Seeds and oil: Food products and animal feed. Oil for cosmetics, lotions and personal care products

    Policy Significance

    • Opens avenues for farmer income diversification
    • Boosts green economy and sustainable industries
    • Potential for employment generation in hill states

    Prelims Takeaway

    • Industrial hemp is legally distinct from narcotic cannabis due to very low THC
    • Multi sector utility crop with applications in textiles, construction, energy, food and cosmetics
    According to India’s National Policy on Biofuels, which of the following can be used as raw materials for the production of biofuels? (2020)

    1. Cassava 

    2. Damaged wheat grains 

    3. Groundnut seeds 

    4. Horse gram 

    5. Rotten potatoes 

    6. Sugar beet 

    Select the correct answer using the code given below: 

    (a) 1, 2, 5 and 6 only (b) 1, 3, 4 and 6 only (c) 2, 3, 4 and 5 only (d) 1, 2, 3, 4, 5 and 6

  • Aloe vera Compounds as Potential Alzheimer’s Inhibitors  

    Why in the news?

    A new study (Current Pharmaceutical Analysis, 2025) suggests that common plant molecules from Aloe vera—especially Beta sitosterol—may inhibit key enzymes associated with Alzheimer’s disease (AD). Findings are based entirely on in silico (computer simulation) techniques.

    What is Computer Simulation (In Silico Research)?

    • Computer simulation, often called in silico research, refers to the use of computational tools and algorithms to model biological, chemical, or physical processes.
    • It allows scientists to predict molecular interactions, drug behavior, and biological outcomes without physical experiments.

    Alzheimer’s Disease (AD) 

    • Most common form of dementia.
    • Characterised by:
      • Memory loss
      • Cognitive decline
      • Accumulation of beta-amyloid plaques and tau tangles
      • Loss of acetylcholine, a neurotransmitter linked to learning and memory.
    • Enzymes involved in acetylcholine breakdown:
      • Acetylcholinesterase (AChE)
      • Butyrylcholinesterase (BChE)
    • Current drugs (e.g., donepezil, rivastigmine) work by inhibiting these enzymes but do not stop disease progression.

    Why Aloe vera?

    • Used for 3000+ years in traditional medicine.
    • Contains bioactive compounds such as Beta sitosterol, Succinic acid, polysaccharides, and phenolics.

    Major Findings

    • Beta sitosterol showed strong binding affinity to both enzymes:
      • AChE: −8.6 kcal/mol
      • BChE: −8.7 kcal/mol
    • The binding strength is higher than that of other screened compounds like Succinic acid.
    • ADMET results suggest:
      • Good absorption
      • Low toxicity
      • Favourable pharmacokinetic profile
    Which one of the following is the context in which the term “qubit” is mentioned? (2022)

    (a) Cloud Services 

    (b) Quantum Computing 

    (c) Visible Light Communication Technologies 

    (d) Wireless Communication Technologies

    This PYQ is chosen because it tests a fundamental concept related to the cutting edge of computational power and modelling, which is the operational domain of computer simulation.