Question

In the given flowchart related to nitrogen cycle, choose the correct option for X and Y.
Atmospheric Nitrogen → Biological Nitrogen Fixation → (X) → Nitrates Ammonification → (Y)

• A. X – Nitrite oxidation bacteria \hspace{0.3cm} Y – Nitrate reducing bacteria
• B. X – Nitrosomonas \hspace{1.6cm} Y – Nitrobacter
• C. X – Nitrosomonas \hspace{1.6cm} Y – Nitrate reducing bacteria
• D. X – Nitrobacter \hspace{1.6cm} Y – Nitrogen fixing bacteria

Hint:

Remember: Nitrosomonas → Ammonia to Nitrite Denitrifying bacteria → Nitrate to Nitrogen gas

Answer 1

The Correct Option is C

Step 1: Understanding the nitrogen cycle.
In the nitrogen cycle, ammonia is first converted into nitrites by Nitrosomonas. This process is called nitrification.

Step 2: Identifying X.
The organism responsible for converting ammonia into nitrites is Nitrosomonas. Hence, X = Nitrosomonas.

Step 3: Identifying Y.
The process shown at Y involves conversion of nitrates back into atmospheric nitrogen, which is carried out by nitrate-reducing (denitrifying) bacteria.

Step 4: Final matching.
Thus, the correct combination is: X – Nitrosomonas Y – Nitrate reducing bacteria