It is very essential that the teachers of science and biology transfer the biology and biotechnology concepts properly by using good programs and teaching strategies as well as the development of biology and biotechnology education programs and models for science teachers and students. In recent years despite the increase of the technological equipments; course books are still the most important source, used in all levels of education, enlightening what the students will learn during the education period, what the teachers will teach and what method will be used during this period. Within this context, scientific quality, language, visuals, diagrams and models, context, technical and physical qualities, used in course books, have necessary roles for the students to learn the concepts properly and relate them to each other. The aim of this research is to study the distribution and relation of the subjects and the concepts of cell, chromosome, DNA, gene, GMO in Secondary School Science and Technology course books and High School Biology course books together with the scientific competency and accuracy level while defining these concepts. In this study, document method from qualitative analysis methods has been used. According to the results of the analysis, it has been identified that there are inadequacies of teaching the mentioned concepts present in the studied course books and relating them in terms of scientific competency and accuracy. (C) 2015 The Authors. Published by Elsevier Ltd.