The heredity disciplinary core idea (DCI) is about the biological mechanisms that underlie many familiar and less familiar phenomena such as genetic disorders, genetically modified foods, gene therapy, and others. Explaining how and why we are similar and different is at the heart of this DCI, and these explanations unfold over time as students gain meaningful understandings of key entities and processes in genetics. We therefore need to be vigilant about how we carve out the scope and sequence of instruction in genetics such that students develop deep and generative understandings of this core idea. In this chapter, we have highlighted a few instructional strategies and tools that we believe can aid in this mission. Providing students with an understanding of this core idea will undoubtedly serve them well in their future. A list of materials, teacher background information, assessment, standards, safety, and references are provided. This book selection also includes the Table of Contents, Foreword, Acknowledgments, About the Editors, Contributors, Appendix, Image credits, and Index.