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प्रश्न
Long Answer Question:
Explain biological nitrogen fixation with example.
उत्तर
Biological nitrogen fixation:
- It is carried out by prokaryotes called as ‘Nitrogen fixers’ or Diazotrophs’.
- It accounts for nearly 70% of natural nitrogen fixation.
- Nitrogen fixers are either symbiotic or free living.
- Symbiotic N2 fixation: The best-known nitrogen-fixing symbiotic bacterium is Rhizobium. This soil living/ dwelling bacterium forms root nodules in plants belonging to the family Fabaceae e.g. beans, gram, groundnuts etc.
- Azotobacter, Azospirillum is free-living nitrogen-fixing bacteria.
- The cyanobacteria fix a significant amount of nitrogen in specialized cells called heterocysts.
- Nitrogen fixation is high high-energy-requiring process and nitrogen fixers use 16 molecules of ATP to fix each molecule of nitrogen to form ammonia.
N2 + 8H+ + 8e- + 16ATP → 2NH3 + H2 + 16ADP + 16Pi
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संबंधित प्रश्न
Name four types of bacteria involved in nitrogen cycle.
Write a note on nitrogen fixation?
Describe nitrogen cycle.
How do human activities affect nitrogen cycle?
When we breathe in air, nitrogen also goes inside along with oxygen. What is the fate of this nitrogen?
Match Column - I with Column - II.
| Column - I | Column - II | ||
| (a) | Nitrococcus | (i) | Denitrification |
| (b) | Rhizobium | (ii) | Conversion of ammonia to nitrite |
| (c) | Thiobacillus | (iii) | Conversion of nitrite to nitrate |
| (d) | Nitrobacter | (iv) | Conversion of atmospheric nitrogen to ammonia |
Choose the correct answer from the options given below.
______ is the primary nutrient, important for the survival of all living organisms.
How are organisms like Pseudomonas and Thiobacillus of great significance in nitrogen cycle?
Name the cell which is responsible for nitrogen fixation in cyanobacteria.
Match the following:
| Column A | Column B (Organisms) | ||
| (1) | Symbiotic nitrogen fixation | (a) | Nitrobacter |
| (2) | Denitrification | (b) | Cyanobacteria |
| (3) | Free living nitrogen fixers | (c) | Rhizobium |
| (4) | Nitrification | (d) | Paracoccus |
