Read Carbon and Phosphorus Reservoirs
Biogeochemical cycles move elements between reservoirs; carbon and phosphorus differ in their atmospheric phases.
Living-system questions are solved by matching a structure or organism to its function, process and stated condition.
Compare carbon and phosphorus
Carbon moves through atmospheric, aquatic, organismal and sedimentary pools. Phosphorus is primarily sedimentary, with Earth’s crust and rocks as major reservoirs and no substantial gaseous phase. Nitrogen is often limiting in marine ecosystems.
Interpret turnover time
Turnover time is the time needed to replace or renew a pool. A component with negligible renewal during an individual's life has a lifetime-scale turnover; central crystalline-lens fibres persist essentially for life. Do not confuse this with the size or location of a nutrient reservoir.
OlympIQ exam lens
- ✓Marine limiting nutrient: often nitrogen.
- ✓Carbon cycle has gaseous and sedimentary pools.
- ✓Phosphorus cycle is mainly sedimentary.
A cycle may have several reservoirs; identify the dominant pool the question asks for.
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