Answer:
Although an individual gene may code for a specific physical trait, that gene can exist in different forms, or alleles. ... In other cases, each parent provides a different allele of a given gene, and the offspring is referred to as heterozygous ("hetero" meaning "different") for that allele.
Because it proves the fertilization was impossible
I think its anaerobic respiration
Carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur
:)
