The cell membrane is made up of
a double layer of cellulose
a single layer of cellulose
a double layer of protein
a double layer of phospholipids

this protocol provides a detailed procedure for nucleoprotein extraction from cultured cells and tissues in an efficient manner.

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.