A Case Study in the Teaching and Learning of Photosynthesis and Respiration in Plants Based on a Teaching Unit

Abstract

This research experience derives from the need to solve the problem “How do seventh-grade students
transform scientific concepts, procedures and attitudes toward science in relation to photosynthesis
and respiration of plants from their experience in problem-solving learning activities and practical
laboratory work? This paper presents interpretations of the development and changes in learning
of a seventh-grade student, as to the content of school science to develop the teaching unit with
problem and experimental activities, based on the history of photosynthesis and respiration in
plants, that meets the general objective: to develop school science concepts, positive predisposition
towards scientific activity and learning attitudes towards biology and procedures of science, and
insight into the nature of science through school scientific activity in the theme of photosynthesis
and respiration in plants. The methodological design, of a qualitative nature, uses the instrumental
case study, which is based through its own history of the institution in the conceptual and attitudinal
contents. The construction, adoption and adaptation of instruments like item interviews with pretest
and post-test scales, lab reports and a didactic unit were needed to understand the development of
student learning in the content and conception of the nature of science. For this reason, we used 

triangulation over time, linear historical sequence, based on longitudinal and cross-sectional studies
for the analysis of information of three cases chosen randomly in this new implementation. The
analysis of the activities determined that the conceptual development of students passes through
phylogenetic explanations, and the conceptual change depends on the formulation of deep causal
explanations. In addition, we identified the procedural development from the opening level and the
attitudinal change towards science influenced by learning attitudes. Finally, content changes and
developments favored the trend of advanced vision in the nature dimension of scientific knowledge.