Endogeny (biology)

{{Short description|Substances & processes originating within an organism, tissue, or cell}}

{{For|endogeny or endogeneity in other contexts|Endogeneity (disambiguation){{!}}Endogeneity|Exogeny}}

Endogeny, in biology, refers to the property of originating or developing from within an organism, tissue, or cell.{{cite web |title=Endogenous | Define Endogenous at Dictionary.com |url=http://dictionary.reference.com/search?q=endogenous |access-date=2011-07-11 |publisher=Dictionary.reference.com}}

For example, endogenous substances, and endogenous processes are those that originate within a living system (e.g. an organism or a cell). For instance, estradiol is an endogenous estrogen hormone produced within the body, whereas ethinylestradiol is an exogenous synthetic estrogen, commonly used in birth control pills.

In contrast, exogenous substances and exogenous processes are those that originate from outside of an organism.