Editing Phenotypic trait (section)

== Definition ==
A [[phenotypic]] trait is an obvious, observable, and measurable characteristic of an organism; it is the expression of genes in an observable way. An example of a phenotypic trait is a specific hair color or eye color. Underlying genes, that make up the [[genotype]], determine the hair color, but the hair color observed is the phenotype. 

The phenotype is dependent on the genetic make-up of the organism, but is also influenced by the environmental conditions  that the organism was subjected to during its [[ontogenesis|ontogenetic]] development,<ref>*{{Citation | last1 = Campbell | first1 = Neil  | last2 = Reece | first2 = Jane | title = Biology  | publisher =Benjamin Cummings}}</ref> including various [[epigenetic]] processes. 

Regardless of the degree of influence of genotype versus environment, the phenotype encompasses all of the characteristics of an organism, including traits at multiple [[levels of biological organization]], ranging from [[behavior]] and [[evolutionary history of life]] traits (e.g., litter size), through morphology (e.g., body height and composition), physiology (e.g., blood pressure), cellular characteristics (e.g., membrane lipid composition, mitochondrial densities), components of [[biochemical]] pathways, and even [[messenger RNA]].{{citation needed|date=March 2023}}