Oxygen is essential to life on Earth. It's produced through photosynthesis and moves through human bodies, water, and Earth's atmosphere. How exactly does that work? Through accessible language and full-color diagrams and photographs, this book explains the oxygen cycle. The text is designed to appeal to readers of all levels, particularly those struggling to understand a standard text book. Fact boxes and an extended glossary allow for the inclusion of the most important science vocabulary so all readers have the ability to understand, speak, and write about the topic.