Question

Phosphorus cycle is

• A. Gaseous cycle
• B. Perfect cycle
• C. Imperfect cycle
• D. Partly gaseous and partly sedimentary

Answer 1

Answer: (C)

Imperfect cycle

Phosphorus cycle is an imperfect cycle because phosphorus does not go back to the source from where it is originated, that is, plants.

A perfect cycle (e.g. the nitrogen cycle) has a readily accessible abiotic, usually gaseous, reservoir and many negative-feedback controls. By contrast, the phosphorus cycle, which has a sedimentary reservoir accessed only by slow-moving physical processes, has few biological feedback mechanisms. Human activities can disrupt these cycles, leading to pollution. Theoretically, perfect cycles are more resilient than imperfect cycles.

The phosphorus cycle is the biogeochemical cycle that describes the movement of phosphorus through the lithosphere, hydrosphere, and biosphere.

The phosphorus cycle process is as follows,

1. The phosphorus enters the soil and water through the weathering of rocks.
   
2. Plants take in these phosphorus ions from the soil.
   
3. The phosphates are then transferred from plants to herbivores animals.
   
4. These herbivores animals are eaten by carnivores.
   
5. The phosphates that are absorbed by the animals are returned to the soil through excretion and from decomposition of plants and dead material by microbes.
   
6. The dead plant materials and other waste products are decayed through the action of bacteria.
   
7. The phosphate is released out to the environment by this process.
   
8. The phosphate in the soil is leached out or eroded into water.
   
9. The water is again utilized by algae and plants as nutrients.
10. So, the correct answer is 'Imperfect cycle'