Basic genetics knowledge for high school students according to teachers and professors and its presentation in textbooks and in reference sources: laxity and rigor

Author(s)

Fernanda Franzolin

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Faculdade de Educação (FE/SBD)
• Defense date: 2012-05-25

Examining board members

Nelio Marco Vincenzo Bizzo; Maria de Nazaré Klautau Guimarães Grisolia; Myriam Krasilchik; Lyria Mori; Maria Elice de Brzezinski Prestes

• Advisor: Nelio Marco Vincenzo Bizzo

Abstract

This research had two main objectives. First, we aimed to identify basic Genetics topics that high school students need to become critical citizens, according to their teachers and university professors. Second, we aimed to determine how close textbook knowledge is to canonical knowledge of these topics. This study was conducted in two sites: São Paulo (São Paulo, Brazil) and Kalamazoo (Michigan, United States). Understanding Genetics is important for understanding other fields in Biology; moreover, Genetics is connected to many everyday issues. Knowledge in Genetics is constantly expanding; this generates reflection on the most important topics to teach. Textbooks are a didactical resource for teaching knowledge in genetics; but, at the same time, they require both didactical transposition and rigorous adherence to scientific knowledge. Thus, the current study interviewed high school teachers of Biology and University professors of Genetics and Molecular Biology (University of São Paulo and Western Michigan University). Data analysis was based on qualitative and qualitative methods. The presentation of knowledge on three topics: Meiosis, Mendels laws, and Gene expression topics, was analyzed by comparing high school textbooks to a bibliography of references. We adopted this bibliography of references as a representative of canonical knowledge, with some precautions. For example, we considered its didactical transposition, and we interviewed one of the authors of the main reference book adopted, Dr. Richard Lewontin, to clarify its elaboration procedures. In the textbook analysis, we considered the importance of rigor in scientific knowledge and the necessity of didactic transposition. Our results showed that a specific group of topics was preponderantly considered basic by interviewees in both contexts. These topics were: the Patterns of inheritance, Cell division, Molecular Genetics (DNA, Gene expression), Biotechnology, and Genes. We also showed that teaching Biotechnology was controversial among interviewees. Many interviewees said that the topics they considered basic were important for students to understand information received in their everday life and the expression of their own traits. However, to that end, we questioned whether it would not be important to place more emphasis on topics related to the expression of complex traits. The arguments presented in the interviews gave rise to reflections on the justification for teaching some topics. In the textbook analysis, the results showed that the relative frequency of approximations to the reference knowledge was higher than the relative frequency of differences from the reference knowledge. The frequencies of differences were almost the same in both contexts: 0.081 in Brazilian textbooks and 0.085 in American textbooks. The majority of differences occurred because some of the specific details related to the topics were omitted in the textbooks; however this did not change the main ideas. The identification of these differences may be useful for improving the didactic transposition of knowledge in Genetics. (AU)