UPSC Prelims 2023 Q12: Environment & Ecology – Biodiversity
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?
- (a) Both Statement - I and Statement - II are correct and Statement - II is the correct explanation for Statement - I
- (b) Both Statement - I and Statement - II are correct and Statement - II is not the correct explanation for Statement - I
- (c) Statement - I is correct but Statement - II is incorrect
- (d) Statement - I is incorrect but Statement - II is correct
Answer: (c) Statement - I is correct but Statement - II is incorrect
Explanation
Marsupials — pouched mammals
| Feature | Fact |
|---|---|
| What they are | Mammals whose young are born tiny and grow in a pouch |
| Where found | Australia, New Guinea and the Americas (opossums) |
| Examples | Kangaroo, koala, wombat, Tasmanian devil, Virginia opossum |
| In India? | None naturally |
Statement I — correct. India has no native marsupials.
Statement II — incorrect. Marsupials live in many habitats — deserts, rainforests, grasslands, eucalyptus woods — and alongside predators such as dingoes, eagles and pythons.
Why they are mostly in Australia:
| Reason | Explanation |
|---|---|
| Continental drift | Australia split from Gondwana early and stayed isolated |
| Little competition | Placental mammals never reached Australia in large numbers |
Answer: (c) Statement - I is correct but Statement - II is incorrect.
Why each option is right or wrong
- (a) Incorrect. Statement II is false, so it cannot be the explanation.
- (b) Incorrect. Statement II is false; marsupials live in deserts, forests and grasslands, with predators.
- (c) CORRECT. India has no native marsupials, but they are not limited to predator-free montane grasslands.
- (d) Incorrect. Statement I is true; marsupials are native only to Australasia and the Americas.
Key point
Marsupials are native to Australasia and the Americas, not India; they live in varied habitats, including with predators.
Remember
No marsupials are native to India; they live in Australia, New Guinea and the Americas.
Common mistakes
- Accepting 'only in montane grasslands' because it sounds scientific; kangaroos live in dry plains and deserts.
- Forgetting the American opossum, which shows marsupials are not only Australian.
- Linking India's lack of marsupials to habitat; the real reason is biogeographic history (continental drift).
Exam tip
Watch for 'only' in Statement II. Absolute words like 'only' or 'always' often make a statement false.
Sources
- NCERT Class XII — Biology, Ch 6 (Evolution — Adaptive radiation of Australian marsupials)
- Zoological Survey of India — Mammals of India