Question

Study the following table about microorganisms and their role in nitrogen fixation. Select the option that best suits (i) - (iv)

Microorganism	Role in nitrogen cycle
(i)	Conversion of nitrate to free nitrogen
Nitrosococcus	(ii)
Nitrocystis	(iii)
(iv)	Conversion of free nitrogen to nitrogen compounds

• A. Pseudomonas Conversion of ammonia to nitrites coversion of nitrite to nitrate Rhizobium
• B. Pseudomanas Conversion of dead plant protein to ammonia Coversion of ammonia to nitrites Penicillium
• C. Azotobacter Conversion of nitrite to nitrate Coversion of nitrate to nitrite Nitrobacter
• D. Azotobacter Conversion of nitrite to nitrite Conversion of dead plant protein to ammonia Nitrosomonas

Answer 1

The correct option is A Pseudomonas Conversion of ammonia to nitrites coversion of nitrite to nitrate Rhizobium

Denitrification is the process by which the free nitrogen is returned back to the atmosphere by sequential degradation of fixed nitrogenous compounds. This process is accelerated by denitrifying bacteria like Pseudomonas.

Bacteria like Nitrococcus converts the ammonia to nitrites by the process of nitrification. Nitrite to nitrite conversion takes place by Nitrocystis.

Rhizobia are soil bacteria that fix nitrogen (diazotrophs) after becoming established inside root nodules of legumes (Fabaceae).

So, the correct answer is option A.