Genotype a person"s particular set of genes that are inherited from his or her parents. Aside from identical twins, no sets of genotypes are the same. Genotypes interact with the environment to produce the phenotype. Phenotype the visible expression of individual"s genetic traits. Characteristics include motor abilities, intellectual skills, and social behavior. Gene chromosome and codes for the production of certain kinds of protein: each protein serves a different function. Some give characteristic physical properties (ex- bone cells get their hardness) other triggerchemical reactions, carrying chemical messages, fighting foreign invaders, regulating genes. Alleles, which are an alternative forms of gene. Typically a gene has two alleles, on inherited from the mother and one from the father. Ex- you have a gene that codes for eye color, one allele is blue eyed color. Human body contains roughly 10 trillion cells, majority containing a nucleus.