There are many distinct processes critical to the process of experiencing pain. takes place at the level of the receptors where chemical, mechanical or thermal energy is converted into electrochemical nerve impulses.

what subject is this

genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).

its probably to later but whats the question