Lesson eLearning

Which of the following mechanisms best explains nitrogen fixation in legume root nodules?

easy MCQ 3 marks Class 9 · Science · Improvement in Food Resources
  1. A) Symbiotic bacteria converting atmospheric N₂ into ammonia
  2. B) Plants absorbing nitrate directly from soil
  3. C) Use of chemical nitrogen fertilizers
  4. D) Photosynthesis producing nitrogen
Answer
A) Symbiotic bacteria converting atmospheric N₂ into ammonia

The correct answer is A) Symbiotic bacteria converting atmospheric N₂ into ammonia — Step 4: Select option A, as it correctly describes the process.

Step-by-step solution

  1. Step 1: Recognise that nitrogen fixation occurs in root nodules of legumes.
  2. Step 2: Identify the role of rhizobia bacteria in converting atmospheric N₂ into usable ammonia.
  3. Step 3: Choose the option that mentions symbiotic bacteria and N₂ conversion.
  4. Step 4: Select option A, as it correctly describes the process.
Common mistake: Confusing nitrogen fixation with nitrate uptake from soil.

Concept tested: Nitrogen fixation in legumes

Published · How this solution was prepared and checked

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