Revise, Reflect, Refine
Choose the most appropriate option to describe the role of biogeochemical cycles in an ecosystem. (i) To provide food directly to all organisms. (ii) To recycle essential nutrients between biotic and abiotic components. (iii) To create new elements for use by living things. (iv) To remove pollutants and toxins from the organism.
Biogeochemical cycles (water, carbon, nitrogen, oxygen) move matter continuously between the living (biotic) and non-living (abiotic) parts of an ecosystem.
Option (i) is incorrect — food is produced by organisms (e.g. plants via photosynthesis), not by biogeochemical cycles directly.
Option (iii) is incorrect — elements such as carbon, nitrogen, and oxygen are not created; they already exist and are simply cycled.
Option (iv) is incorrect — removing pollutants is not the defining function of biogeochemical cycles.
Option (ii) correctly captures the core role: these cycles ensure that essential nutrients (C, N, O, water, etc.) are continuously exchanged and recycled between biotic components (plants, animals, microbes) and abiotic components (atmosphere, soil, water), keeping ecosystems functional.
Answer: (ii) To recycle essential nutrients between biotic and abiotic components.