Evolution is change in a population over time and includes the gene pools of that population. How does biogeographic
isolation allow for the change of gene pools over time?

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.

i think the answer is b.

true                                                                                                       true true true true true true