The only united states floral organization that has a nationally recognized and certified floral-design designation is the

American Institute of Floral Designers

Explanation:

The American Institute of Floral Designers is a non-profit organization established in 1965 in the USA. The objective of this institute is to stimulate, promote and help the creation of artistic works in the floral area of talented professionals who wish to be recognized as professionals. This is the only floral organization in the United States that has a nationally recognized and certified floral designation designation.

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.

a unit of heredity that is transferred from a parent to offspring and is held to determine some characteristic of the offspring.