Question

Choose the statements that correctly differentiate between phosphorus and carbon cycle.
I. Phosphorus is released into the atmosphere due to respiratory activities while carbon is not
II. Carbon is released into the atmosphere due to respiratory activities while phosphorus is not
III. Phosphorus cycle is sedimentary while carbon cycle is gaseous
IV. Lithosphere is the reservoir for phosphorus cycle while atmosphere is the reservoir for carbon cycle

• A. I, III and IV
• B. II, III and IV
• C. II and III
• D. I and IV

Answer 1

The correct option is B II, III and IV

Movement of nutrients occurs through various biotic and abiotic components of the ecosystem and is termed as biogeochemical cycles. It is of two types based on the reservoirs -

• Gaseous cycle - The reservoir exists in the atmosphere. Example: Nitrogen, carbon, etc.
• Sedimentary cycle - The reservoir exists in the earth’s crust (lithosphere). Examples : Sulphur, phosphorus, etc.

Hence statement III and IV are correct.

A large amount of carbon is released in the atmosphere by respiratory activities of producers and consumers. Rocks are the natural reservoir of phosphorus (in the form of phosphates). Phosphate-solubilising bacteria release small amounts of phosphorus to into the soil by decomposing dead plants and animals but there is no respiratory release of phosphorus to the atmosphere. Hence statement II is correct but statement I is incorrect.