Question

Nitrogen fixation in root nodules of alnus is brought about by
A. Frankia
B. Azorhizobium
C. Bradyrhizobium
D. Clostridium

Answer 1

Hint: Nitrogen fixation is a process during which molecules of nitrogen within the air are converted into ammonia in soil as molecular nitrogen is useless to use directly.

Complete Answer:
- Nitrogen is that vital element. The atmosphere is the greatest reservoir of nitrogen so it's present within the air within the abundant form.
- Molecular nitrogen which is present within the air can't be utilized directly by plants, it has to be converted into compounds before utilization. Rhizobium species are included in the Symbiotic organic process which occurs on the roots of leguminous plants.
- But to make nodules so on, convert it into compound nitrogen, non-leguminous plants like Alnus are involved. The best known example involved in nodule formation is an actinomycetes called Frankia.
- Clostridium is anaerobic and free-living nitrogen fixing bacteria. Bradyrhizobium is symbiont in soybean plants of soybean. The Azorhizobium develops both stem and root nodules in aquatic plants.

Thus the correct answer is A ’Frankia'.

Note: Organic process is significant to life. As a part of the nitrogen cycle, it's important for agriculture as well as manufacture of fertilizer.