Teachers often struggle to facilitate open discussions about evolution when they perceive it to be at odds with cultural and religious norms. Little is understood about classroom discourse and teacher-student interactions during the teaching of evolution. This study analyzed classroom discourse and teacher-student exchanges in a 10th-grade biology classroom at a rural high school during the evolution and human genetics units. It also considered contextual factors such as the teacher's acceptance and understanding of evolution and his perspective on the nature of science [NOS]. A microanalysis of classroom discourse showed that lecturing and recitation were the most commonly used discourse patterns. While the intent of the teacher's questions and their impact on students' subsequent responses varied across dialogue patterns, the most frequent objective of the teacher's questions in both units was to assess correctness. The teacher's feedback mostly acknowledges responses, confirms correct answers, and reiterates responses. The teacher displayed a comprehensive understanding of all aspects of NOS. He also demonstrated a strong acceptance of evolution. The questionnaire results and his teaching throughout the unit indicated a high understanding of evolution. This study suggested that teachers with solid acceptance and a well-informed understanding of evolution may still utilize teacher-dominated discourse patterns and ask questions primarily to obtain factual knowledge.