The Status of the Concepts ‘Hereditary Trait’ and ‘Phenotype’ in Secondary School Textbooks

Abstract

In this time of rapid genetic knowledge development, students’ genetic understanding is still problematic in secondary education. The current emphasis in genetics education on Mendelian segregation and single-gene inheritance models lacks the richness of today’s scientific understanding and may lead to a poor understanding of genetics and a deterministic view on genetics. Many factors in this problem have been identified, but it is likely that also student understanding of the genetic concepts hereditary traits and phenotype is problematic and much narrower than in biological science. Textbooks are an important factor contributing to students’ understanding. In this study, the two major Dutch secondary school biology textbooks were analysed and use of the terms hereditary traits and phenotype was classified according to six categories in which the concepts were expected to differ from scientific use. It was found that only part of the aspects of these concepts as described in the categories were covered in the textbooks and that conceptual variation and inconsistent use of the terms may contribute to problematic genetic understanding. Most of the textbook examples of hereditary traits and phenotype were about simple genetically determined Mendelian monogenetic characteristics. The next generation therefore might be insufficiently prepared for future decisions on genetics related problems.