Nitrogen Cycle Processes Identification

Steps:

• Identify P as the process converting ammonia to nitrates, which is nitrification.
• Identify Q as bacteria converting atmospheric N2 to ammonia, which is nitrogen fixation.
• Identify R as bacteria converting nitrates back to N2 gas, which is denitrification.
• Identify S as decomposers breaking down organic matter to release ammonia, which is decomposition.

Why D is correct:

• D matches the standard nitrogen cycle: P (nitrification), Q (nitrogen fixation), R (denitrification), S (decomposition), aligning with biological definitions of each step.

Why the others are wrong:

• A incorrectly swaps Q and S as nitrogen fixation and misplaces denitrification.
• B duplicates nitrogen fixation for P and Q, ignoring nitrification and decomposition roles.
• C is incomplete and cannot be evaluated.

Not enough information for full verification without diagram.

Final answer: D