Question

Which is the best explanation of the role that marine organisms play in the cycling of atmospheric gases through oceans?

1) They cycle hydrogen, carbon, and nitrogen through all their life processes.
2) They cycle oxygen and carbon through their respiration (breathing).
3) They cycle oxygen and carbon through their consumption and digestion.
4) They cycle carbon and nitrogen through food webs and their decomposition.

Answer 1

Marine organisms play a crucial role in cycling carbon and nitrogen through food webs and decomposition, contributing to the biogeochemical cycles that affect atmospheric gases.

Step-by-step explanation:

The role that marine organisms play in the cycling of atmospheric gases through oceans can be best explained by understanding their contribution to biogeochemical cycles, like the carbon cycle and the nitrogen cycle. Marine autotrophs, such as phytoplankton, fix carbon dioxide into organic compounds like glucose during photosynthesis, which in turn produces oxygen as a byproduct. Moreover, both carbon and nitrogen are cycled through food webs and the decomposition of organisms; marine organisms like cyanobacteria are essential in fixing inorganic nitrogen into forms usable by other living beings.

In summary, option (4) 'They cycle carbon and nitrogen through food webs and their decomposition' is the best explanation, as marine organisms play a crucial role in the carbon and nitrogen cycles, affecting the atmospheric gases significantly, including the production of a substantial amount of the oxygen we breathe.