2022 GS Paper I, all questions

UPSC Prelims 2022 · GS Paper I

Question 48: Environment and Ecology

Which of the following are nitrogen-fixing plants ?

  1. 1.Alfalfa
  2. 2.Amaranth
  3. 3.Chickpea
  4. 4.Clover
  5. 5.Purslane (Kulfa)
  6. 6.Spinach

Select the correct answer using the code given below :

a1, 3 and 4 only
b1, 3, 5 and 6 only
c2, 4, 5 and 6 only
d1, 2, 4, 5 and 6

AnswerUPSC’s answer is (a).

Nitrogen-fixing plants are legumes that host Rhizobium bacteria in root nodules. Alfalfa, chickpea and clover are legumes and fix atmospheric nitrogen. Amaranth, purslane (kulfa) and spinach are leafy plants, not legumes, and they do not fix nitrogen themselves. So the answer is 1, 3 and 4 only.

  • 1. Alfalfa is a legume with nitrogen-fixing root nodules.
  • 2. Amaranth is not a legume.
  • 3. Chickpea is a legume.
  • 4. Clover is a legume.
  • 5. Purslane is not a legume.
  • 6. Spinach is not a legume.

How you could have got this

  1. If you were sure statement 5 is not correct, (b), (c) and (d) go: each of them includes 5.

    What you needed to know: Purslane is not a legume.

Only (a) is left. You didn’t need statements 1, 2, 3, 4 or 6.

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) Correct. Alfalfa, chickpea and clover are legumes.
  • (b) Wrong. Purslane and spinach are not nitrogen fixers.
  • (c) Wrong. Amaranth, purslane and spinach are not nitrogen fixers.
  • (d) Wrong. Amaranth, purslane and spinach are not nitrogen fixers.

Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.

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Source: UPSC, Civil Services (Preliminary) Examination 2022, General Studies Paper I, Series A. The paper on upsc.gov.in.