This study explored five Life Sciences teachers' practices of formative assessment when enacting an inquiry-based pedagogy. The ESRU cycle (teacher "Elicits" a response; the Student responds; the teacher "Recognises" the student's response; and then "Uses" the information collected to support student learning) was used as a coding system in the analysis of speaking turns involving exchanges between the teachers and learners. By tracking the strategies teachers used in terms of ESRU cycles, we were able to capture differences in assessment practices across the five teachers during inquiry science lessons. The findings of the analysis revealed patterns of teacher-learner interaction described as IRE (Initiation, Response, Evaluation) that are suggestive of 'incomplete' ESRU cycles. In the assessment conversations, there was absence of the crucial step of Using information about student learning in order to support students in the construction of knowledge. The findings of his study signal the need for professional development in supporting teachers in their formative assessment practices. This development can be in the form of workshops that focus on strategies for formative assessment such as those that are encapsulated in the ESRU framework. It is also recommended that best practices in formative assessment be modelled to teachers.