Amino acids are the building blocks of life and are encoded by DNA. Enzymes and structural proteins are made of amino acids, and are used as precursors for other important biomolecules in the body. In addition, many different industries ranging from pharmaceuticals to the food industry rely on amino acids.
Crossing over – often, the sister homologous chromosomes of a cell exchange genetic material through recombination of genes.
Independent assortment/random fertilization – there are numerous variety of ways that the chromosomes of the gametes can combine, after meiosis, through fertilization to form a zygote
Mutation – on rare occasion, there is a slight and random change in the genes of a gametic cell caused by environmental factors.