doi:10.1007/s10763-026-10656-0engMazas Gil, BeatrizBravo Torrija, BeatrizMartín García, JorgeDeveloping a model of bacteria: a journey through the understanding of prospective early childhood teachersART-2026-148462This work aims to identify the development of the model of bacteria described by 369 prospective teachers of early childhood education, collected over eight academic years. The objective is to determine their pre-existing ideas about bacteria and the evolution after completing a sequence involving work on scientific skills. Before and after the sequence the participants are asked 'What is a bacterium?' The participants’ responses are subjected to content analysis. Initial results show a simplified model of bacteria. In their final models, they are able to add new characteristics such as type of cell or reproduction. There is also an increase in the number of students who mention the beneficial activities of bacteria. Regarding location, they acknowledge that bacteria are ubiquitous. Therefore, we identify an evolution of their model of bacteria towards one that is closer to the scientific reference model, although it is still incomplete.2026http://zaguan.unizar.es/record/16997710.1007/s10763-026-10656-0http://zaguan.unizar.es/record/169977oai:zaguan.unizar.es:169977INTERNATIONAL JOURNAL OF SCIENCE AND MATHEMATICS EDUCATION 24, 24 (2026), 1-24byhttps://creativecommons.org/licenses/by/4.0/deed.esinfo:eu-repo/semantics/openAccess