The allele combinations are?
O genetics
O mitosis
O genotype
O phenotype

genotype

Explanation:

Within an individual organism, the specific combination of alleles for a gene is known as the genotype of the organism, and (as mentioned above) the physical trait associated with that genotype is called the phenotype of the organism.

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.