1. The document defines PCK as the blending of content and pedagogy knowledge into an understanding of how to organize and adapt subject matter for diverse learners. It also discusses different categories of teacher knowledge including content knowledge, pedagogical knowledge, and knowledge of learners.
2. PCK is important for effective teaching as it allows teachers to identify difficult concepts, plan instruction, and acquire new teaching strategies. Having PCK enables teachers to represent knowledge in ways that make it comprehensible for learners.
3. PCK differs from content knowledge in that it represents the transformation of content into teaching practice tailored to specific learners and topics. The document emphasizes the role of PCK in science teaching.