This paper is the result of a research which analyses the meanings of Photosynthesis elaborated by students in the fifth grade of Primary School. The content was developed through an investigative activity using the representational multimodality in the text format, image, besides dialogic interaction through oral way between students and the teacher. The meanings, produced in each activity, were analysed based on the Meaningful Learning aspect. It was possible to verify that the activities provided differentiation and enrichment of the initial meanings which were established in the cognitive students’ structure.