This project focuses on identifying knowledge and skill gaps in a major science teaching subject in senior secondary school, specifically Biology. The gaps are identified in the topics of 'Stem Cell Research' and 'Organ and Tissue transplantation'. The report discusses research undertaken to identify these gaps, analysis of professional knowledge and skills, and proposes a professional learning model to resolve the identified gaps. The goal is to ensure that the teacher has expertise in all the topics of the major science teaching subject.