Where does the po32– come from that circulates due to upwelling? select all that apply. a. dead organisms from the marine food web b. fixation of other phosphorus compounds by archaea c. liberation through atp hydrolysis in living organisms d. the atmosphere?

a. dead organisms from the marine food web.

c. liberation through ATP hydrolysis in living organisms.

Upwelling is a wind driven motion of lower bottom nutrient rich and warmer water on the surface of the water body. This wind driven motion facilitates the movement of nutrients available for growth of primary producers like phytoplanktons growing on the surface of water body. The dead organisms from the marine food web get decomposed and the organic matter obtain after decomposition is a rich source of phosphorous. This phosphorous gets transferred to the upper layers of the water body by upwelling.  In aquatic organisms ATP hydrolysis occurs which is a catabolic process that uses water to split the bonds present in the ATP molecule and hence, releases energy for functions performed by them along with a release in phosphate atom. This phosphate gets mixed with the water. Therefore, PO32 come from dead organisms from the marine food web and liberation through ATP hydrolysis in living organisms that circulates due to upwelling.  

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.