The change of the secondary school students' conceptual understanding levels regarding the subject of genetics: A longitudinal research

The aim of the study is to examine the conceptual understanding levels and misconceptions of secondary school students about genetics longitudinally, to create novel mind maps to compare students' conceptualizations about genetics and to try to determine the learning resources related to students' genetic concepts. The study was conducted as a longitudinal case study. The study group who were selected by similar sampling method consisted of 35 students studying at a project Anatolian High School in Izmir. "Conceptual Understanding Test on Genetics" was administered at the 9th and 10th classes, "Conceptual Understanding Test on Advanced Genetics" was administered at the 11th and 12th classes. "Genetic Key Concept Questionnaire" and "Genetic Concepts Learning Resource Test" were applied at each grade level. It was understood that as the grade level of the students increased, they had higher conceptual understanding levels for the Conceptual Understanding Test on Advanced Genetics. It was determined that students had many misconceptions, they could not establish the relationship between genes, DNA and chromosomes, they did not fully understand the concept of mutation and protein synthesis. The two concepts that came to students' minds the most were DNA and gene, the concepts that came to their minds first were gene, DNA, biology concepts. It was determined that students generally did not use the National Education Informatics Network resource. Various suggestions were made such as using the conceptual understanding level scoring key in different subjects, investigating the origins of identified misconceptions, and using novel mind maps in education.