The biogeochemical cycle that includes the processes of buffering the ocean and photosynthesis, as shown in the diagram, is the carbon cycle.

• The carbon cycle involves the exchange of carbon between the atmosphere, ocean, and living organisms. Photosynthesis by marine organisms (like phytoplankton) extracts CO2 from the atmosphere and converts it into organic carbon, forming the base of the marine food web. This process is a key part of the biological carbon pump that transfers carbon to deeper ocean layers

• Ocean buffering refers to the ocean's ability to regulate pH and resist drastic changes in acidity. This buffering is largely controlled by the carbonate system, which is part of the carbon cycle. The ocean alkalinity and carbonate chemistry help maintain pH balance through processes that include dissolution of carbonate minerals and uptake of CO2 during photosynthesis

Thus, the carbon cycle uniquely encompasses both photosynthesis and ocean buffering processes, linking biological activity with chemical regulation in marine environments