Genetic information is transferred through biological processes studied at different levels of granularity. Focusing on the continuity and change of genetic information and its phenotypic expression thus yields a cross-cutting theme in biology. The inspiring aim of this work is to integrate this theme into the knowledge base of an electronic biology textbook. The paper describes first steps in this regard. We present a definition of the theme to set its scope, sketch competency questions for future evaluation, and systematically identify a set of information (bearing) units as key notions of the theme. Due to the central role of genetic information in biomedical research, continuing the work towards the taxonomic classification of those key notions connects with their occurrence in biomedical ontologies. Besides the taxonomy in the knowledge base, we briefly survey selected ontologies regarding the notions of gene, DNA, and DNA sequence. Beyond specific analyses, this leads us to conclude with the need for novel solutions in dealing with multiple, but integrated perspectives on biological terms and for the efficient management of detailed ontological distinctions.