UPSC Prelims 2026 · GS Paper I
Question 22: Environment and Ecology
With respect to the Western Hoolock Gibbons, which of the following statements is/are correct ?
- 1.A Sanctuary in North-east India is home to this ape species listed as Endangered in the International Union for Conservation of Nature (IUCN) Red List.
- 2.They have specialized brachiation and can easily swing between trees.
- 3.They possess a strong and heavy build like gorillas, yet are remarkably agile tree climbers.
Select the answer using the code given below :
AnswerUPSC’s answer is (b).
The Western Hoolock Gibbon is listed Endangered by IUCN, and hoolock gibbons are India's only apes. The Hoolock Gibbon Wildlife Sanctuary at Jorhat in Assam is its best-known home in the north-east. Gibbons are lesser apes: slender, long-armed and built for brachiation, swinging arm over arm between trees. The strong, heavy build is a feature of gorillas, which are great apes.
- 1. A sanctuary in Assam shelters this IUCN Endangered ape.
- 2. Gibbons are specialised brachiators.
- 3. Gibbons are slender and light; heavy build is a gorilla feature.
How you could have got this
- If you were sure statement 1 is correct, (c) and (d) go: each of them leaves 1 out.
What you needed to know: A sanctuary in Assam shelters this IUCN Endangered ape.
- Then, if you were sure statement 2 is correct, (a) goes: it leaves 2 out.
What you needed to know: Gibbons are specialised brachiators.
Only (b) is left. You didn’t need statement 3.
This follows UPSC’s provisional key; the final key could change it.
Which options go is worked out from UPSC’s key and the options, not by a model.
Why each option is right or wrong
- (a) Incomplete: statement 2 is also correct.
- (b) Right: the sanctuary and the brachiation are correct.
- (c) Wrong: statement 3 describes gorillas, not gibbons.
- (d) Wrong: statement 3 is incorrect.
Only the provisional key (27 May 2026) was found; the final key replaces it when found.
Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2026, General Studies Paper I, Series A. The paper on upsc.gov.in.