Learning science requires students to conceptualize complex scientific concepts, discover scientific facts, and share ideas with others. In this process, scientific vocabulary and language of science help students develop their understanding of science. Given the interlink between language and conceptual development, the current study aimed to improve seventh-grade students' scientific vocabulary and communicative interactions using teaching materials designed for the "cell and divisions" subject. Through an embedded mixed research design, the study was conducted with 31 (21 girls, 10 boys) students (aged 13-14 years) drawn from a middle school in the city of Trabzon, Türkiye. A scientific vocabulary test, observation form, and video recordings were used to collect data. The findings showed significant improvements in students' scientific vocabulary and communicative interactions. Future studies should examine the effect of students' scientific vocabulary on communicative development.