A tissue is a group of that world together to preform a common function

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.

because they are eaten by the frog and the frog getseaten by the snake and the snake by the eagle

b. to discover aspects of the natural world.

hopefully i .

answer///multiple alleles;