Endosymbiosis is a mutually beneficial relationship between a host organism and an internal associate organism. The term is derived from the prefix "endo," meaning within, and the word symbiosis, which refers to a mutually beneficial...

Once considered a relative rarity, endosymbiosis, the living together of one organism inside another, has increasingly become recognized as a major factor in the evolution of life forms. The word endosymbiosis comes from Greek words meaning...

An endosymbiont is any organism that lives within the body or cells of another organism, i.e. forming an endosymbiosis (Greek: endo = inner, sym = together and biosis = living). Examples are nitrogen-fixing bacteria (called rhizobia) which live in root...