Simon Broadley has been teaching secondary science for 18 years, specialising in biology and applied science, and with responsibility for leading Biology and BTEC courses. Simon has a PhD and BSc in microbiology. Simon has been an OUP author for seven years, writing student and teacher resources for KS3 and GCSE. Mark Matthews has been teaching secondary science for over 20 years, specialising in Biology and AppliedScience, and with responsibility for leading biology and BTEC courses. Mark has a PhD in Developmental Biology and a BSc in Zoology. An experienced author, Mark has been writing for OUP for seven years, with published student and teacher materials for KS3 and GCSE. Dr Andrew Chandler-Grevatt has a PhD in school assessment, and a real passion forscience teaching and learning. Having worked as a science teacher for ten years, of which five were spent as an AST, Andy has a real understanding of the pressures and joys of teaching in the classroom. Alongside his national and international research in school assessment, Andy is a teaching fellow on the PGCE course at the University of Sussex, and is a successful published assessment author.