This study is base on a constructivist framework in which children are regarded as active participants in the constructing and structuring of their knowledge of the world around them. The overall purpose of this research is to describe the development of children s conceptions and understanding about a biological process as revealed by their ideas concerning the process of decomposition and its importance in nature. The study also showed that the language, traditional, cultural up-bringing of children, folk lore and myths exert an enormous influence on children s concept development. The study found age related and gender related differences. Finally, educational implications of the findings are discussed and suggestions made for teaching methods, as well as for further research.