Question
UPSC Prelims 2022 Question:
Which of the following are nitrogen-fixing plants?
- Alfalfa
- Amaranth
- Chickpea
- Clover
- Purslane (Kulfa)
- Spinach
Select the correct answer using the code given below:
Answer (Detailed Solution Below)
Option 1: 1, 3 and 4 only
Detailed Solution
Explanation:
- Symbiotic nitrogen fixation by alfalfa provides substantial amounts of nitrogen (N) to livestock operations, subsequent crops, and soil organic matter. So, point 1 is correct.
- Chickpeas form root nodules that support biological N fixation (BNF) and host symbiotic N-fixing bacteria. So, point 3 is correct
- Nitrogen is "fixed" in clovers through a symbiotic relationship with Rhizobium bacteria that infects the plant's roots. The plant provides energy for the bacteria, and bacteria provide the "machinery" necessary to convert atmospheric nitrogen into a form available to plants. So, point 4 is correct.
- Amaranth, Purslane (Kulfa), Spinach are not are nitrogen-fixing plants. So, points 2, 5 and 6 are not correct.
Therefore, option (1) is the correct answer.
Subject: Environment|Terrestrial and Aquatic Ecosystem
Latest UPSC Exam 2026 Updates
Last updated on March, 2026
