The 5th edition of this glossary has been completely revised, updated and supplemented by up-to-date terms used in genetic engineering and molecular genetics. Where necessary, a short essay explaining an entry in more detail is added to the stated definition. Wherever possible, the author of an entry is mentioned and the respective publication cited. Cross-references ease the orientation within the glossary. This glossary on genetics, molecular genetics and genetical engineering is intended for students and researchers.