Key biological are defined in a way that all readers can understand in this book that explains the essential concepts of life processes and how living and nonliving things relate to each other. The basics of feeding, respiration, waste, and reproduction, among other important activities that sustain living things, are explained in clear, simple language, with colorful photographs to illustrate them. Non-living things are defined and described, as well. Each section also includes text boxes that define key and reading comprehension activities with thought-provoking questions.