What is Life? 2e PrepU Mobile is designed to be an on-the-go companion to the bestselling Biology textbook, What Is Life? A Guide to Biology by Jay Phelan. Complement your studies by quizzing yourself with this mobile version of PrepU, the adaptive learning platform. This app features close to 8,000 questions correlated to the biology content in the book, What is Life? 2e, and contains a full range of recall, application, and critical-thinking questions aligned to Bloom’s taxonomy levels.