Measure
Photosynthesis questionnaire developed by Marmaroti and Galanopoulou (2006) composes of 24 questions covering all aspects of photosynthesis. Four questions related to the content of this study were selected and used to determine students’ prior knowledge about the origin of plant nutrients, the substances required for photosynthesis, the products of photosynthesis and the role of chlorophyll. The questionnaire was administered before and after the instruction and the students’ responses were analyzed to describe how students’ conceptions had changed over the instruction.