definition of an observable trait
A phenotype (from Greek phainein, meaning to show, and typos, meaning type) is the composite of an organism 's observable characteristics or traits, such as its morphology, development, biochemical or physiological properties, phenology, behavior, and products of behavior (such as a bird's nest).nother extension adds behavior to the phenotype, since behaviors are also observable characteristics. Indeed, there is research into the clinical relevance of behavioral phenotypes as they pertain to a range of syndromes.