The effect of STEM activities about dna and genetic code unit on the secondary school 8th grade students' conceptual understanding

The positive effects of STEM education activities on the variables of academic achievement, attitude, motivation and 21st century skills have a guiding effect on the integration of curricula. The fact that the effects of STEM education on the conceptual understanding variable have been investigated relatively less constitutes the skeleton of the research. This study aims to examine the effect of STEM activities about DNA and genetic code unit on the secondary school 8th grade students' conceptual understanding where misconceptions are often seen in the literature of the science teaching programme. Experimental design with pretest-posttest control group, which is one of the quantitative research methods was used in the research. The research was carried out 2022-2023 academik year with 58 students (30 experiments, 28 control) on the public secondary school 8th grade in Adana province in Seyhan. In the control group, the activities in the MEB textbook were applied in accordance with the strategies foreseen by the current program while experimental experiments were prepared according to the 5E model and STEM activities were applied. As a data collection tool, the 2-stage DNA and Genetic Code Unit Conceptual Understanding Test (DNAGCUT) developed by the researcher and used. The normality analyses of the data obtained from DNAGCUT (The general and sub-dimensions of the test) were analyzed by Shapiro-wilk test. T-tests were used for the analysis of data with normal distribution, Mann Whitney U test and Wilcoxon Signed Ranks Test were used for the analysis of data without normal distribution. As a result of research; when the DNAGCUT pre-test and post-test scores of the experimental group students were compared; a significant difference was detected between the scores obtained from the general test and DNA, heredity, mutation-modification-adaptation and biotechnology sub-dimension in favor of the final test. When the DNAGCUT pre-test and post-test scores of the control group students were compared a significant difference was detected between the scores obtained from the general test and DNA, heredity and mutation-modification-adaptation sub-dimensions in favor of the final test. While the DNAGCUT post-test scores of the experiments and control groups were compared a significiant difference was not detected between the scores obtained from the general test, DNA, heredity and mutation-modification-adaptation sub-dimensions, on the other hand a significiant difference was detected between the scores obtained from biotechnology sub-dimension.