The 2020 Codex
Questions 41 to 50 (Set A)
With reference to carbon nanotubes, consider the following statements:
1. They can be used as carriers of drugs and antigens in the human body.
2. They can be made into artificial blood capillaries for an injured part of human body.
3. They can be used in biochemical sensors.
4. Carbon nanotubes are biodegradable.
Which of the statements given above are correct?
The Secret Whisper
Official Key: (c) 1, 3 and 4 only
Carbon Nanotubes (CNTs) are cylindrical molecules consisting of rolled-up sheets of single-layer carbon atoms (graphene). They are revolutionary in nanomedicine.
Statements 1 and 3 are True: Because they are hollow, they can act as perfect nano-syringes for targeted drug delivery directly into cancer cells. Their high electrical conductivity makes them excellent biosensors.
Statement 4 is True: Recent studies show that appropriately functionalized CNTs can be enzymatically degraded (biodegraded) by human enzymes like myeloperoxidase inside macrophages.
Statement 2 is False: While polymers and nanofibers are used for artificial blood vessels, constructing actual functioning artificial blood capillaries exclusively out of Carbon Nanotubes poses severe toxicity and thrombosis risks at a macro-tissue level. The UPSC deemed this specific application incorrect.
Route: [REALM 506: Nanoscience & Nanomaterials] & [REALM 511: Nanomedicine]The Nano Cylinder
The Unmanned Eyes
Consider the following activities:
1. Spraying pesticides on a crop field
2. Inspecting the craters of active volcanoes
3. Collecting breath samples from spouting whales for DNA analysis
At the present level of technology, which of the above activities can be successfully carried out by using drones?
The Secret Whisper
Official Key: (d) 1, 2 and 3
Unmanned Aerial Vehicles (UAVs / Drones) have fundamentally changed data collection in dangerous or inaccessible environments.
1: Agricultural drones are heavily used globally (and now via India's Drone Didi scheme) to spray pesticides with pinpoint precision.
2: Drones are routinely flown into active volcano craters (like Mount Etna) equipped with thermal cameras and gas sensors to monitor eruptions safely.
3: Marine biologists use modified drones (famous dubbed "SnotBots") to fly through the blowhole spouts of surfacing whales to collect biological samples (mucus) for DNA and virus analysis without disturbing the massive animals.
Route: [REALM 417: Drone Tech, UAVs] & [REALM 286: Drones & Ethics]"The experiment will employ a trio of spacecraft flying in formation in the shape of an equilateral triangle that has sides one million kilometres long, with lasers shining between the craft." The experiment in question refers to
The Secret Whisper
Official Key: (d) Evolved LISA
LIGO detected gravitational waves on Earth. But Earth is noisy (earthquakes, traffic). To detect the massive, low-frequency gravitational waves from supermassive black hole mergers, the European Space Agency (ESA) proposed LISA (Laser Interferometer Space Antenna), now known as eLISA (Evolved LISA).
It consists of three spacecraft flying millions of kilometers apart in a perfect equilateral triangle trailing the Earth in orbit. They will beam lasers between each other. If a gravitational wave rolls through the solar system, it will stretch space slightly, altering the distance the lasers travel by a fraction of an atom, confirming the wave.
Note: LISA Pathfinder (C) was just a single test-satellite launched in 2015 to prove the technology worked, not the final 3-craft triangle.
Route: [REALM 119: Gravitational Waves] & [REALM 378: Major Global Space Missions]The Cosmic Triangle
The Master Sculptor
Consider the following statements:
1. Genetic changes can be introduced in the cells that produce eggs or sperms of a prospective parent.
2. A person's genome can be edited before birth at the early embryonic stage.
3. Human induced pluripotent stem cells can be injected into the embryo of a pig.
Which of the statements given above is/are correct?
The Secret Whisper
Official Key: (d) 1, 2 and 3
Statement 1 is True: This is known as Germline Gene Therapy. Using CRISPR-Cas9, scientists can genetically modify spermatogonial stem cells or oocytes (eggs) to remove inherited diseases, meaning the changes will be passed down to future generations.
Statement 2 is True: Embryonic genome editing is scientifically possible. In 2018, Chinese scientist He Jiankui notoriously and illegally edited the genomes of human embryos to make them HIV-resistant, resulting in the birth of the first gene-edited babies.
Statement 3 is True: This refers to creating Chimeras. Scientists successfully injected human induced pluripotent stem cells (iPSCs) into a pig embryo to grow human organs (like a heart or liver) inside the pig for eventual human organ transplantation.
Route: [REALM 241: CRISPR & Gene Therapy] & [REALM 249: Stem Cells & Engineering]What is the importance of using Pneumococcal Conjugate Vaccines in India?
1. These vaccines are effective against pneumonia as well as meningitis and sepsis.
2. Dependence on antibiotics that are not effective against drug-resistant bacteria can be reduced.
3. These vaccines have no side effects and cause no allergic reactions.
Select the correct answer using the code given below:
The Secret Whisper
Official Key: (b) 1 and 2 only
Statement 1 is True: The bacterium Streptococcus pneumoniae doesn't just cause severe pneumonia in children; it can also enter the bloodstream (causing sepsis) and the brain (causing meningitis). The PCV protects against all these severe invasive pneumococcal diseases.
Statement 2 is True: By preventing the infection from occurring in the first place through vaccination, we drastically reduce the need to prescribe antibiotics, helping combat Antimicrobial Resistance (AMR).
Statement 3 is False: This is a classic absolute trap. There is no vaccine or medicine on Earth that has "no side effects and causes no allergic reactions". Mild side effects like fever or arm soreness are common, and rare allergic reactions can occur.
Route: [REALM 317: Vaccination Technologies]The Conjugate Shield
The Cipher Vault
In India, the term "Public Key Infrastructure" is used in the context of
The Secret Whisper
Official Key: (a) Digital security infrastructure
Public Key Infrastructure (PKI) is the foundational cryptography framework that secures the modern internet. It governs the issuance of digital certificates and manages public-key encryption (a mathematical system using a public key to encrypt data and a private key to decrypt it). When you see "HTTPS" on a website, or when you use an Aadhaar e-Sign, you are relying entirely on the digital security infrastructure provided by PKI to ensure your data cannot be intercepted or forged.
Route: [REALM 503: Data Protection & Cyber Infra]Which of the following statements are correct regarding the general difference between plant and animal cells?
1. Plant cells have cellulose cell walls whilst animal cells do not.
2. Plant cells do not have plasma membrane unlike animal cells which do.
3. Mature plant cell has one large vacuole whilst animal cell has many small vacuoles.
Select the correct answer using the code given below:
The Secret Whisper
Official Key: (c) 1 and 3 only
Statement 1 is True: The hallmark of a plant cell is a rigid outer cell wall made of cellulose, which provides structural support. Animal cells lack this wall entirely (allowing them to be flexible).
Statement 2 is False: ALL living cells on Earth (plant, animal, bacteria) have a plasma membrane (cell membrane). In plants, the plasma membrane sits just *inside* the rigid cell wall.
Statement 3 is True: A mature plant cell has a massive central vacuole (holding water and maintaining turgor pressure) that can occupy up to 90% of the cell's volume. Animal cells have several much smaller vacuoles.
Route: [REALM 144: Cell Structure & Organelles] & [REALM 147: Membranes & Transport]The Cellular Divide
The Aromatic Ring
Which of the following are the reasons/factors for exposure to benzene pollution?
1. Automobile exhaust
2. Tobacco smoke
3. Wood burning
4. Using varnished wooden furniture
5. Using products made of polyurethane
Select the correct answer using the code given below:
The Secret Whisper
Official Key: (a) 1, 2 and 3 only
Benzene (C₆H₆) is a highly carcinogenic aromatic hydrocarbon. The absolute primary source of benzene in the environment is the incomplete combustion of organic matter.
Therefore, automobile exhaust (burning petrol/diesel), tobacco smoke (burning tobacco leaves), and wood burning (burning biomass) are direct, massive sources of benzene emission. (Statements 1, 2, and 3 are correct).
While varnished furniture and polyurethane products do off-gas toxic Volatile Organic Compounds (VOCs) that cause indoor air pollution, they primarily emit Formaldehyde and Toluene, not Benzene. Hence, UPSC excluded 4 and 5 from the official key.
Route: [REALM 152: Air Pollution] & [REALM 169: Carcinogens]If another global financial crisis happens in the near future, which of the following actions/policies are most likely to give some immunity to India?
1. Not depending on short-term foreign borrowings
2. Opening up to more foreign banks
3. Maintaining full capital account convertibility
Select the correct answer using the code given below:
The Secret Whisper
Official Key: (a) 1 only
How does a country survive a global financial panic? By building a fortress against capital flight.
Statement 1 is True: Short-term foreign borrowings ("hot money") are extremely dangerous. If a global crisis hits, foreign lenders will panic, refuse to roll over the short-term debt, and demand their dollars back immediately, crashing the local currency (like the 1997 Asian Financial Crisis). Not depending on this gives immense immunity.
Statements 2 and 3 are False: Opening up to more foreign banks directly links your domestic banking system to Wall Street's failures. Maintaining "full capital account convertibility" means anyone can instantly convert billions of Rupees into Dollars and pull them out of the country without RBI restrictions. Both of these policies would expose India to devastating capital flight, eliminating immunity.
Route: [REALM 134: Global Financial Conditions & India] & [REALM 178: Capital Account Convertibility]The Sovereign Fortress
The Closed Loop
If you withdraw ₹ 1,00,000 in cash from your Demand Deposit Account at your bank, the immediate effect on aggregate money supply in the economy will be
The Secret Whisper
Official Key: (d) to leave it unchanged
This is a pure conceptual test of how "Broad Money" (M3) is calculated.
M3 = Currency with the Public + Demand Deposits with Banks + Time Deposits.
When you walk into an ATM and withdraw ₹1 lakh from your checking account, you are simply subtracting 1 lakh from the "Demand Deposits" variable and adding exactly 1 lakh to the "Currency with the Public" variable. Because both variables exist within the same M3 bracket, the overall sum equation remains perfectly identical. The money has just changed its physical form, leaving the aggregate money supply completely unchanged.
Route: [REALM 112: Money & Monetary System]