Which one of the following is not a gaseous biogeochemical cycle in an…

Concept

Biogeochemical cycles move essential elements between living organisms and the non-living environment. They are classified by the location of their principal reservoir.

A gaseous cycle has a major atmospheric or oceanic reservoir, whereas a sedimentary cycle stores most of the element in rocks, soil, and sediments and lacks a significant atmospheric phase.

Application

Phosphorus is stored mainly in phosphate-bearing rocks and sediments. It enters ecosystems through weathering, passes through organisms, and returns through decomposition and sedimentation; therefore its cycle is sedimentary rather than gaseous.

Contrast

• Oxygen cycle: the atmosphere is a major reservoir, and photosynthesis, respiration, and oxidation move oxygen through the system.

• Nitrogen cycle: atmospheric nitrogen is the major reservoir, and fixation, nitrification, assimilation, and denitrification connect it with living systems.

• More than one of the above: oxygen and nitrogen are gaseous cycles, so the requested non-gaseous category does not contain more than one listed named cycle.

• None of the above: phosphorus supplies a listed non-gaseous cycle, so the set is not empty.

Cross-check

Hence, the cycle that is not gaseous is the phosphorus cycle.