International Journal of New Trends in Arts, Sports & Science Education
Yazarlar: Gonca HARMAN
Konular:
Anahtar Kelimeler:Misconceptions,Prediction-observation-explanation method,The passage of substances through the cell membrane ,Preservice science teacher.
Özet: In order to determine preservice science teachers' misconceptions about the passage of substances through the cell membrane, an activity was prepared. 73 preservice teachers did this activity that was prepared based on Prediction-Observation-Explanation (POE) method in laboratory in the fall semester of 2012-2013. In prediction section, preservice teachers were asked to estimate changes in the cell that was put in isotonic, dilute and concentrated medium. They were asked to write prediction and reasons of prediction. In observation section, they were asked to do experiment, make observation and write their observations. In explanation section, they were asked to compare predictions with observations. They were asked to define isotonic, hypotonic and hypertonic medium. They were asked to answer some questions. What happens when cell is put in saltwater and after cell is put in water? What are the events that occur these conditions? How medium is saltwater? The data was analyzed with descriptive analysis. The findings of study are presented follows. When cell is put in a solution that is equal to concentration of cell, substance passes to cell. Cell that is put in dilute solution loses water and shrinks. Dilute solution has a lower water concentration than the cell. Cell that is put in concentrated solution gains water and swells. Density of concentrated medium is lower than concentration of cell and cell gains water in concentrated medium. Cell that become plasmolysis gains water and swells. Cell that become deplasmolysis shrinks. Salt solution is hypotonic medium; cell become deplasmolysis in the salt solution. Cell that become deplasmolysis in the salt solution become plasmolysis in water. Hypertonic medium is dilute medium. Concentration of hypotonic medium is higher than concentration of cell. Concentration of hypotonic medium is equal to concentration of cell. The results of the study showed that they had misconceptions about dilute solution, concentrated solution, plasmolysis, deplasmolysis, isotonic, hypotonic and hypertonic medium. Also this activity was provided that they realized their misconceptions.