Providing complete step-by-step coverage of the 2008 Edexcel GCE Biology specification, Salters-Nuffield Advanced Biology (SNAB) is the official support material for the context-led approach to the specification. Written by the University of York Science Education Group (UYSEG) and Nuffield Curriculum Centre, this Students' Book gives students an in-depth, scientific understanding of the principles covered in each topic, including How Science Works.