What, if anything, do teachers need to know about how the brain works to improve teaching and learning? After all, a plumber needs to know how to stop leaks--not the molecular structure of water. And one can learn how to use a computer without knowing how a computer chip works. Likewise, teachers need to know how to help students develop intellectually and learn--not necessarily how their brains work. Nevertheless, it is important for teachers to understand that what is being discovered about how brains work supports constructivist learning theory, which in turn supports inquiry-based teaching. The goal of the present article is to explicate why this is so. The author starts with some of the basics of brain development. The author then discusses the implications of neuroscience research for science teaching and learning. (Contains 4 figures.)