Why is the history of any part of the ocean floor important

The history of the ocean floor is important because it can be a tell tale sign of how the plate tectonics are moving. It can show how new the ocean floor through subduction. Divergent and convergent plate boundaries on the ocean floor (which can create trenches and mid ocean-ridges) also show if the plates are pulling apart or coming together along the ocean floor.

explanation:

b,bacteria convert nitrates

into nitrogen gas.

d,plants and animals take in

and use nitrogen compounds.

e,bacteria break down waste    

products and return nitrogen  

to the soil.

a,bacteria convert atmospheric

nitrogen to ammonia.

c,bacteria convert ammonia

to nitrites and nitrates.