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Home » UPSC Prelims Quiz » UPSC Prelims Quiz: October 24, 2025

UPSC Prelims Quiz: October 24, 2025

Q1. Assertion (A) and Reason (R)
Assertion (A): The recent increase in India’s female labour force participation rate indicates a structural improvement in women’s employment.
Reason (R): Between 2017–18 and 2023–24, women’s participation in paid regular employment and real earnings have both risen substantially across sectors.

Which of the following is correct?

(a)

Both A and R are true, and R is the correct explanation of A

(b)

Both A and R are true, but R is not the correct explanation of A

(c)

A is true, but R is false

(d)

A is false, but R is true

Explanation

FLFPR rose from 23.3% in 2017–18 to about 41.7% in 2023–24 (PLFS data). However, most of this rise is attributed to distress employment, unpaid self-employment, and informal work, not to structural improvements.

Real earnings of women declined for regular and self-employed categories during the same period (CEDA & NSSO data).

Thus, while the data confirm a rise in participation, it does not reflect qualitative gains in women’s employment.

Correct Answer: (d) A is false, but R is true
Q2. Which of the following correctly describes the significance of India’s 2025 Elephant Census results?
(a)

They confirm a decline in elephant population across all landscapes.

(b)

They provide a scientifically robust baseline for future monitoring.

(c)

They indicate recovery of elephant habitats in Central India.

(d)

They replace Project Elephant as the main conservation programme.

Explanation

The 2025 report clarifies that the DNA-based estimate serves as a scientific baseline for monitoring India’s elephant populations, not as a measure of population decline.

Project Elephant continues as the overarching national conservation scheme; no replacement has occurred.

Answer: (b)
Q3. In the context of wildlife population estimation, consider the following techniques:

I. Distance Sampling

II. Line Transect Method

III. DNA Mark–Recapture

IV. Camera Trap-based SECR Models

Which of the above methods rely on individual identification of animals for population estimation?

(a)

I and II only

(b)

II and IV only

(c)

III and IV only

(d)

I, III and IV only

Explanation

DNA mark–recapture identifies individual animals genetically, allowing population estimation through re-identification of DNA samples.

Camera-trap SECR (Spatially Explicit Capture–Recapture) models also rely on identifying individual animals based on unique stripe or spot patterns.

Distance sampling and line transect methods estimate density indirectly through encounter rates and detection probabilities, without using unique individual identification.

Answer: (c) III and IV only
Q4. With reference to the 2025 Synchronous All-India Elephant Estimation (SAIEE), consider the following statements:

I. The 2025 estimation used a DNA-based mark–recapture technique to identify individual elephants.

II. The new estimate cannot be directly compared with the 2017 census because of a change in methodology.

III. The Wildlife Institute of India conducted the exercise under Project Elephant.

How many of the statements given above are correct?

(a)

Only one

(b)

Only two

(c)

All three

(d)

None

Explanation

All statements are correct.

The 2025 census employed a DNA-based mark–recapture technique instead of traditional visual or dung count surveys, allowing identification of individual elephants.

It was conducted by the Wildlife Institute of India (WII) under Project Elephant.

The Ministry of Environment, Forest and Climate Change clarified that the 2025 figures are not directly comparable with those of the 2017 census due to a change in methodology.

Answer: (c) All three

India’s 2025 Elephant Census

India’s latest elephant census under the Synchronous All-India Elephant Estimation (SAIEE) 2021–25, released in October 2025, estimates the wild elephant population at 22,446 using a new DNA-based technique. This appears lower than the 2017 count of 29,964, but experts note that the figures are not directly comparable due to a shift in methodology — from traditional dung and visual counts to the more accurate DNA mark–recapture approach.

Population Estimate

The 2025 census, conducted by the Wildlife Institute of India (WII) under Project Elephant, used Spatially Explicit Capture–Recapture (SECR) models that combine genetic data from dung samples and habitat variables.
  • Total dung samples collected: 21,056 across 6.66 lakh km of trails
  • Individual DNA profiles generated: 4,065 elephants
The report clarifies that this new number should serve as a scientific baseline for future monitoring rather than be seen as evidence of an actual decline.

Regional and State Distribution

Elephants are spread across four major landscapes:
  • Western Ghats – 11,934 (largest population)
  • North Eastern Hills & Brahmaputra Flood Plains – 6,559
  • Shivalik Hills & Gangetic Plains – 2,062
  • Central India & Eastern Ghats – 1,891
State-wise distribution:
  • Karnataka – 6,013
  • Assam – 4,159
  • Tamil Nadu – 3,136
  • Kerala – 2,785
  • Uttarakhand – 1,792
  • Odisha – 912

Shift in Method and Conservation Concerns

The shift to DNA-based estimation resolves inconsistencies in earlier state-level methods that used varied counting techniques. By identifying elephants through unique genetic markers, the new system improves reliability, especially in fragmented landscapes.
However, major conservation concerns persist — including habitat loss, corridor fragmentation, and rising human-elephant conflicts, notably in Central India and Assam.
India continues to hold over 60% of the global Asian elephant population, reaffirming its crucial role in global elephant conservation efforts.
Q5. With reference to global ecosystem restoration initiatives, consider the following statements:

1. The UN Decade on Ecosystem Restoration is a legally binding agreement under the UNFCCC.

2. The Bonn Challenge is a mandatory afforestation commitment under the Paris Agreement.

3. Target 2 of the Kunming–Montreal Global Biodiversity Framework (2022) relates to protection of forests, not restoration.

How many of the statements given above are correct?

(a)

Only one

(b)

Only two

(c)

All three

(d)

None

Explanation

Statement 1: Incorrect. The UN Decade on Ecosystem Restoration (2021–2030) is a UNGA-endorsed voluntary initiative, co-led by UNEP and FAO — not a legally binding UNFCCC treaty.

Statement 2: Incorrect. The Bonn Challenge (2011) is a voluntary global partnership led by IUCN and Germany, focused on restoring degraded and deforested landscapes, not on afforestation or Paris Agreement commitments.

Statement 3: Incorrect. Target 2 of the Kunming–Montreal GBF calls for effective restoration of at least 30% of degraded ecosystems by 2030 — it concerns restoration, not mere protection.

Answer: (d) None
Q6. With respect to the three greenhouse gases — Carbon dioxide (CO₂), Methane (CH₄) and Nitrous oxide (N₂O) — consider the following statements:

1. N₂O has a higher 100-year global-warming potential (GWP) than CH₄.

2. CH₄ remains in the atmosphere significantly longer than N₂O.

3. CO₂ remains in the atmosphere many times longer than CH₄.

Which of the above statements is/are correct?

(a)

Only 1

(b)

Only 2

(c)

1 and 3

(d)

2 and 3

Explanation

Statement 1 – Correct: Over a 100-year horizon, nitrous oxide (N₂O) has a much higher GWP (about 270–273 times that of CO₂) compared to methane (CH₄), which is around 28–30 times. (Source: IPCC AR6, 2021)

Statement 2 – Incorrect: Methane is short-lived, remaining in the atmosphere for about 12 years, while nitrous oxide lasts around 100–120 years.

Statement 3 – Correct: Carbon dioxide persists for hundreds to thousands of years, making its atmospheric lifetime far longer than methane.

Answer: (c) 1 and 3
Q7. The cumulative impact of carbon dioxide (CO₂) on global warming arises mainly because of which of the following factors?
(a)

Its heat-trapping capability per unit mass is greater than that of CH₄ and N₂O

(b)

It remains in the atmosphere for a far longer time than CH₄ and N₂O

(c)

Nearly all CO₂ emitted by natural processes is not absorbed back by sinks

(d)

Its global emissions are entirely anthropogenic in origin

Explanation
  • Option (a) – Incorrect: CO₂ has a lower per-unit heat-trapping potential compared to CH₄ and N₂O.
  • Option (b) – Correct: CO₂ stays in the atmosphere for centuries or even millennia, giving it a strong cumulative warming effect despite its lower potency.
  • Option (c) – Incorrect: Natural CO₂ emissions are largely balanced by natural sinks such as oceans and forests.
  • Option (d) – Incorrect: CO₂ emissions arise from both natural and anthropogenic sources; only the anthropogenic fraction leads to net accumulation.
Answer: (b) It remains in the atmosphere for a far longer time than CH₄ and N₂O
Q8. Based on recent scientific assessments, which one of the following statements is the least accurate?
(a)

Over a 20-year timescale, CH₄ has a GWP more than 80 times that of CO₂.

(b)

N₂O is approximately 270 times more potent than CO₂ in terms of warming over a 100-year horizon.

(c)

Despite its lower per-unit potency, CO₂ accounts for the largest share of global warming because of its longer residence time and greater cumulative emissions.

(d)

Since natural sinks absorb nearly all natural CO₂ emissions, the warming effect arises solely from anthropogenic CO₂ emissions.

Explanation
  • Option (a) – Correct: Methane’s 20-year GWP is about 80–84 times that of CO₂ (IPCC AR6).
  • Option (b) – Correct: Nitrous oxide’s 100-year GWP is around 270 times that of CO₂.
  • Option (c) – Correct: CO₂ contributes most to cumulative warming due to its longevity and large total emissions.
  • Option (d) – Incorrect: While anthropogenic CO₂ drives the imbalance, it is not correct to say warming arises solely from it; natural fluxes also interact dynamically, and “nearly all” natural CO₂ is not instantaneously absorbed.

Therefore, option (d) is the least accurate statement.

Answer: (d) Since natural sinks absorb nearly all natural CO₂ emissions, the warming effect arises solely from anthropogenic CO₂ emissions.