Question

Which of the following statement(s) is/are correct about biogeochemical cycle?
(i) Gaseous exchanges of phosphorus between organism and environment are negligible
(ii) All biogeochemical cycles include both organisms and non-living components.
(iii) Most elements remain longest in the living portion of their cycle.
(iv) The chemical elements used by organisms in large quantities cycle back and forth between organisms and environment.

• A. (i) and (iii)
• B. (i), (ii) and (iv)
• C. (i), (ii) and (iii)
• D. All of these

Answer 1

Answer: (B)

Regarding biogeochemical cycles, statement (i), (ii), and (iv) are correct. Biogeochemical cycle is the flow of chemical elements and compounds between living organisms and the physical environment. Chemicals absorbed or ingested by organisms are passed through the food chain and returned to the soil, air, and water by such mechanisms as respiration, excretion, and decomposition. As an element moves through this cycle, it often forms compounds with other elements as a result of metabolic processes in living tissues and of natural reactions in the atmosphere, hydrosphere, or lithosphere