The research which led to this Ph.D. dissertation was carried out under the guidance of Prof. Jayashree Ramadas at the Homi Bhabha Centre for Science Education, Tata Institute of Fundamental Research, Mumbai. We investigated how middle school students use visual and verbal forms of thinking, reasoning and communication to express understanding of the human body. Understanding of structure, function and the relationships between them in the context of the digestive, the respiratory and the circulatory systems was probed. We assessed their basic knowledge using a scheme, based on a common...