Despite rapid changes in education, science classrooms will remain central forums where fragmented pieces of information are brought together to construct coherent knowledge as concepts and explanatory scientific storylines. There is limited work stressing the importance of the interplay between how content is communicated through pedagogical link-making and the use of communicative approaches. Even less research addresses the role of coherence in this process. In this study, through exploring three cases of teachers teaching the same topic, we will bring forth differences on how links between past and to be learned scientific knowledge are made. We look at how authorship -- whether teacher or students make the links -- is related to students cognitively and emotionally engaged with the discussion. Besides revealing differences in these aspects, communicational coherence was found manifesting in different levels in the examples. Based on the findings, we discuss the role of communicational coherence and pedagogical link-making in meaningful learning of science.