1. In genetics, the phenotype (from Ancient Greek φαίνω (phaínō) 'to appear, show' and τύπος (túpos) 'mark, type') is the set of observable characteristics or traits of an organism. The term covers all traits of an organism other than its genome, however transitory: the organism's morphology (physical form and structure), its developmental processes, its biochemical and physiological properties whether reversible or irreversible, and all its behavior, such as a peacock's display. An organism's phenotype results from two basic factors: the expression of an organism's unique profile of genes (its genotype) and the influence of environmental factors experienced by that same organism which influence the variable expression of said genes, and thereby shape the resulting profile of defining traits. Since the developmental process is a complex interplay of gene-environment, gene-gene interactions, there is a high degree of phenotypic variation in a given population that extends beyond mere genotypic... from wikipedia.org