Chapter 2, Problem 36A

Summary Introduction

To determine:

The role of decomposers in the nitrogen cycle.

Introduction : The exchange of matter through the biosphere is called biogeochemical cycle. Nitrogen cycle is one such biogeochemical cycle in which nitrogen is recycled from atmosphere into compounds that can be used by plants.

Answer to Problem 36A

Decomposers help in the return of nutrients back to the cycle at every level.

The decomposers in the soil decompose the dead organisms and transform the nitrogen in proteins and other compounds into ammonia.

Explanation of Solution

Nitrogen is returned to the soil in several ways. Decomposers play an important role in this. They act upon the dead plants and animal wastes and break down the plant and animal proteins and other nitrogenous compounds into ammonia. The ammonia is then acted upon by certain soil bacteria that convert it to nitrates that can be used by plants. Finally, the denitrifying bacteria convert fixed nitrogen compounds back into nitrogen gas thus completing the nitrogen cycle.