A) Fixation: when bacteria turns nitrogen into ammonium so that it can be used by plants
B) Assimilation: when the plants absorb the nitrates from the soil and from their roots. The nitrogen is then used for chlorophyll, nucleic acids and amino acids.
C) Nitrification: is the process where bacteria changes the ammonium to nitrates and the plants absorb these nitrates.
D) Ammonification: is when the plant or animal dies, and the decomposers turn the nitrogen back into ammonium and then it returns to the nitrogen cycle. Remember that decomposers are bacteria and fungi.
Therefore, the correct match of terms and definitions is:
A) Fixation
B) Assimilation
C) Nitrification
D) Ammonification


