An analysis of Life Sciences textbooks' representation of the relationship between photosynthesis and respiration

Abstract

Topics such as photosynthesis and respiration are interrelated. From the literature, it is evident that learners cannot make the connections between topics such as photosynthesis and respiration, and for this reason it is important that textbooks make these connections; it is thus important that the content within textbooks is accurate and of good quality. This study analysed three Grade 10 and 11 South African Life Sciences textbook series to determine how the textbooks represent the relationship between concepts of photosynthesis and respiration, especially as these topics relate to what occurs in plants. The textbooks were analysed to determine whether the content is in accordance with the CAPS document. Subsequently, the content of the textbooks was compared to the standards as set by the AAAS, ASPB and NGSS. Common misconceptions regarding photosynthesis and respiration were identified from the existing literature and the textbooks were investigated for the extent to which these misconceptions are addressed in the textbooks. This study found that the two topics (photosynthesis and respiration) are discussed in two separate sections. There is limited mention of photosynthesis in the respiration chapter, and respiration in the photosynthesis chapter, so that links between the two topics are not well made. Even though the content is in accordance with what is stated in the CAPS document, the textbooks could make the flow of matter and energy more explicit. It was found that the Grade 10 textbooks lay down a foundation for the Grade 11 content and links the structure of the organelles (chloroplasts and mitochondria) and organs (leaf) to photosynthesis and respiration. With regards to the misconceptions, it was found that the textbooks do not directly address these, and even though correct facts are given in the textbooks, this might not be sufficient to correct the misconceptions that learners might have. The results of this study could highlight potential problems and challenges related to how textbooks relate the concepts of photosynthesis and respiration, and could contribute to further research and the design of quality curriculum materials.