ASKiIMAN™
NEXUS / 2023 / GS1
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UPSC 2023: Nexus 11—20

Unearthing the structural logic of the paper. [Set A]

Question 11

Energy Security

Consider the following statements:

  • Statement-I: India, despite having uranium deposits, depends on coal for most of its electricity production.
  • Statement-II: Uranium, enriched to the extent of at least 60%, is required for the production of electricity.

Which one of the following is correct in respect of the above statements?

Official Verdict: (c) Statement-I is correct but Statement-II is incorrect

The Core Concept: India does indeed run mostly on coal (over 70% of generation capacity) despite local uranium reserves (Jaduguda, Tummalapalle). The trap is in Statement-II: Civilian nuclear power reactors only require Low-Enriched Uranium (LEU), usually between 3% to 5% U-235. Enrichment to 60% or 90%+ is Highly Enriched Uranium (HEU), strictly reserved for weapons-grade material or specialized naval propulsion.

Tethered to: REALM 461: Nuclear Reactors & Types

COAL (70%) NUCLEAR (3%) 60% U-235 Only 3-5% needed!
INDIA No Pouches AUSTRALIA

Question 12

Biogeography

Consider the following statements:

  • Statement-I: Marsupials are not naturally found in India.
  • Statement-II: Marsupials can thrive only in montane grasslands with no predators.

Which one of the following is correct in respect of the above statements?

Official Verdict: (c) Statement-I is correct but Statement-II is incorrect

The Core Concept: Marsupials (mammals that carry young in pouches) exist naturally in Australasia and the Americas (like opossums), but completely missed the evolutionary boat to the Indian subcontinent due to continental drift. Statement II is absurdly restrictive; marsupials thrive in deserts, rainforests, and woodlands, and constantly face predators (dingoes, Tasmanian devils, eagles).

Tethered to: REALM 66: Biodiversity Distribution

Question 13

Environmental Institutions

'Invasive Species Specialist Group' (that develops Global Invasive Species Database) belongs to which one of the following organizations?

  • (a) The International Union for Conservation of Nature
  • (b) The United Nations Environment Programme
  • (c) The United Nations World Commission for Environment and Development
  • (d) The World Wide Fund for Nature

Official Verdict: (a) IUCN

The Core Concept: The ISSG is a global network of scientific and policy experts on invasive species, operating directly under the Species Survival Commission (SSC) of the IUCN. They act as the world's librarians for biological invasions, tracking flora and fauna that destroy native ecosystems.

Tethered to: REALM 69: Invasive Alien Species

IUCN
MACAQUE Diurnal CIVET SAMBAR Nocturnal/Crepuscular

Question 14

Animal Behavior

Consider the following fauna:

  1. Lion-tailed Macaque
  2. Malabar Civet
  3. Sambar Deer

How many of the above are generally nocturnal or most active after sunset?

Official Verdict: (b) Only two

The Core Concept: Macaques are primates, and like humans, the Lion-tailed Macaque is highly active during the day (diurnal) foraging in the canopy. The Malabar Civet is strictly nocturnal, hunting in the dark. The Sambar Deer is largely crepuscular (active at dawn/dusk) and nocturnal, utilizing the cover of darkness to graze safely.

Tethered to: REALM 84: India's Biodiversity Regions

Question 15

Zoology & Communication

Which of the following organisms perform waggle dance for others of their kin to indicate the direction and the distance to a source of their food?

  • (a) Butterflies
  • (b) Dragonflies
  • (c) Honeybees
  • (d) Wasps

Official Verdict: (c) Honeybees

The Core Concept: One of nature's most brilliant communication systems. A scout honeybee returning to the hive performs a figure-eight "waggle dance". The angle of the waggle run relative to gravity translates directly to the angle of the food source relative to the sun. The duration of the waggle communicates the exact distance.

Tethered to: REALM 312: Apiculture / Beekeeping

θ = Sun Angle
+ Fungi: The Chemical Masters

Question 16

Mycology & Biochemistry

Consider the following statements:

  1. Some mushrooms have medicinal properties.
  2. Some mushrooms have psycho-active properties.
  3. Some mushrooms have insecticidal properties.
  4. Some mushrooms have bioluminescent properties.

How many of the above statements are correct?

Official Verdict: (d) All four

The Core Concept: Fungi are vast chemical factories. Medicinal: Penicillin, Reishi. Psychoactive: Psilocybin (magic mushrooms). Insecticidal: Entomopathogenic fungi like Cordyceps literally hijack and kill insects. Bioluminescent: Over 70 species of fungi emit light (foxfire) to attract spore-spreading insects at night.

Tethered to: REALM 131: Protists, Fungi, Plants, Animals

Question 17

Faunal Habits

Consider the following statements regarding the Indian squirrels:

  1. They build nests by making burrows in the ground.
  2. They store their food materials like nuts and seeds in the ground.
  3. They are omnivorous.

How many of the above statements are correct?

Official Verdict: (a) Only one

The Core Concept: Unlike temperate ground squirrels, the famous Indian Giant Squirrel and the common Palm Squirrel are arboreal. They build large globular nests high up in the branches, not ground burrows. Because the tropics offer year-round food, they generally do not cache (bury) food for winter. They are, however, omnivorous, opportunistically eating insects and bird eggs alongside nuts and fruits.

Tethered to: REALM 84: India's Biodiversity Regions

No Burrows!
>100°C <0°C pH < 3

Question 18

Microbiology

Consider the following statements:

  1. Some microorganisms can grow in environments with temperature above the boiling point of water.
  2. Some microorganisms can grow in environments with temperature below the freezing point of water.
  3. Some microorganisms can grow in highly acidic environment with a pH below 3.

How many of the above statements are correct?

Official Verdict: (c) All three

The Core Concept: Extremophiles break the rules of classical biology. Thermophiles (like Methanopyrus kandleri) thrive in deep-sea hydrothermal vents at 122°C. Psychrophiles actively reproduce in Antarctic sea ice at -15°C. Acidophiles thrive in highly corrosive sulfuric acid environments with a pH near zero (e.g., Rio Tinto or Yellowstone hot springs).

Tethered to: REALM 128: Viruses, Prokaryotes, Eukaryotes

Question 19

Primatology

Which one of the following makes a tool with a stick to scrape insects from a hole in a tree or a log of wood?

  • (a) Fishing cat
  • (b) Orangutan
  • (c) Otter
  • (d) Sloth bear

Official Verdict: (b) Orangutan

The Core Concept: Tool use is a hallmark of high primate intelligence. Orangutans (and chimpanzees) are famous for modifying sticks—stripping leaves to make a perfect probe—to fish termites, ants, or honey out of deep cavities in logs. Sloth bears have long claws for digging bugs, and otters use rocks to smash shells, but they do not manufacture stick tools.

Tethered to: REALM 141: Human & Hominin Evolution

HFCs

Question 20

Environmental Chemistry

Consider the following:

  1. Aerosols
  2. Foam agents
  3. Fire retardants
  4. Lubricants

In the making of how many of the above are hydrofluorocarbons used?

Official Verdict: (c) Only three

The Core Concept: Hydrofluorocarbons (HFCs) were introduced to replace ozone-destroying CFCs under the Montreal Protocol. Today, they are ubiquitous as propellants in aerosols, blowing agents in foams, and in specific fire retardants (like FM-200). However, HFCs are fundamentally refrigerants and propellants; they are not used as mechanical lubricants (which are oil/silicone-based). Thus, only three apply.

Tethered to: REALM 221: Ozone Depletion