Abstract: This article is dedicated to studying the impact of the spheres of genetics and genetic engineering and their impact upon the formation of corresponding term system in the modern Russian, English and Spanish languages. In the course of research, the author examines the origin of the key genetic terminological units along with their certain etymological and structural-systemic peculiarities. The article determines and explores the main stages in development of the spheres of genetics and genetic engineering from the perspective of emergence and functionality of the corresponding terminological units, interrelation of genetics with other spheres of human activity. The selection of Russian, English and Spanish terms pertinent to the sphere of genetics and genetic engineering – total of approximately 300 units picked from the books, scientific articles, electronic and printed dictionaries and glossaries, as well as Internet portals on the topic, served as the material for this article. The conclusion is made that the development of term systems of genetics and genetic engineering is inseparable from establishment of the corresponding referential spheres. It is underlined that the genetic terminology in the modern Russian, English and Spanish languages has a significant amount of terminological borrowings from other term systems, particularly biology, medicine, chemistry, physics, and others. Despite this fact and close link of the spheres of genetics and genetic engineering with the aforementioned sciences, the spheres under consideration are independent and sector-specific, functioning within their terminological units.