UPSC Prelims 2018 GS Paper I · Q86 of 100 Environment & Ecology easy

Why is a plant called Prosopis juliflora often mentioned in news ?

  1. (a) Its extract is widely used in cosmetics.
  2. (b) It tends to reduce the biodiversity in the area in which it grows. ✓ UPSC's answer
  3. (c) Its extract is used in the synthesis of pesticides.
  4. (d) None of the above

Why the answer is (b)

• Prosopis juliflora (vilayati kikar / seemai karuvelam), a thorny tree from Central America introduced for fuelwood and afforestation, has become a highly invasive species in India.

• It spreads aggressively, draws down groundwater with deep roots, suppresses native plants by allelopathy and shade, and offers little to native fauna, thereby reducing biodiversity — option (b); Tamil Nadu and Delhi have run removal campaigns.

• It is not notable for cosmetics (a) or pesticide synthesis (c).

• Hence option (b).

Why the other options are wrong

(a) Its extract is widely used in cosmetics.
It is not known for cosmetic use.
(c) Its extract is used in the synthesis of pesticides.
It is not a pesticide source.
(d) None of the above
Option (b) is correct, so 'none' is wrong.

Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2018, held on 3 June 2018. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.

Reading the answer is not the same as getting it right under a clock. Practise this question with UPSC's negative marking, and anything you miss goes into an error notebook until you get it right twice.

Practise this paper free