The compulsory learning areas of geography and science in the Australian Curriculum have inquiry as a major pedagogical approach in learning and teaching. In this paper we argue that teacher-informed professionalism is critical in an inquiry to develop student knowledge and skills in geography and science. This includes the effective and efficient use of the steps in an inquiry and the ‘Backward design process’. Assessment, teaching strategies and learning experiences are designed to achieve the goals of the inquiry from the outset. We conclude that professional teaching using guided inquiry maximises the learning gains of students, as it is highly brain compatible for students and their teachers.