The aim of this article is to explore how socially and culturally shaped resources for meaning-making are used in a translanguaging science classroom and how these interact to promote multilingual students’ participation and understanding of science. The data consist of video- and audio-recorded science lessons in a Swedish compulsory school (Grades 4–6). The analysis, rooted in translanguaging and sociocultural perspectives on learning, views learning as dialogic processes within social contexts and is framed within social semiotic theory, both regarding systemic functional linguistics and social semiotic perspectives on multimodality. Multimodal interaction analysis is used to clarify the use of semiotic resources by students, the science teacher and the mother-tongue teacher, as well as their various functions in meaning-making processes. Findings show how the participants’ linguistic repertoires contribute to semiotic resources in the dialogic conversations and how each expression provides a unique aspect of the subject content, which together shape a comprehensive whole. By combining and integrating different modalities, such as gestures, drawings, and objects with verbal resources, continuity is fostered in the science activities. However, the study also underlines the importance of verbal language resources for students’ opportunities to develop a broader and deeper knowledge in science subjects.