GAMETE formation occurs via a process called MEIOSIS. During meiosis, segregation and independent assortment of genes occur. According to Gregor Mendel who proposed the law, the law of segregation states that the alleles of a Gene will separate into gametes. This separation occurs in such a way that only one allele of that gene is found in each gamete.
In this case, an organism with genotype "Aa" will produce gametes that contains the following: A and a. Therefore, the gametes of genotype Aa will be A and a.
Well, nitrogen is the gas that makes up 78% of the earth's atmosphere.
I would guess its in the air that we breathe. I am not really sure. Just basing this answer off of research.
