The observed distribution of alleles into gametes is an illustration of

structure is maintained and sustained by:

-cytoskeleton: gives cells coherence

-cell wall: support

-cytoplasm: shape

hope this .

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.