This text focuses on the scientific principles of the agricultural industry. Designed for use in high school agriscience courses, the aim of the text is to provide students with a basic understanding of the concepts behind the agricultural industry. Traditionally, high school agriculture texts have concentrated on the ?how? behind the industry. The Science of Agriculture: A Biological Approach, third Edition concentrates more on the ?why? behind the industry. Topics include plant and animal systems, soils, cell functions, genetics, genetic engineering, plant and animal reproduction, entomology, the uses of biotechnology, and careers. The text also includes a thorough examination of the controversy and concerns over the use of genetic engineering, genetically modified organisms, cloning, and their perceived and potential dangers to humans and the environment. Each chapter begins with clearly-stated learning objectives, followed by key terminology. Chapters close with student learning activities intended to extend learning beyond the text material. End-of-chapter test questions, in True/False; Short Answer/Discussion; and Multiple Choice formats help to evaluate students? understnading of the concepts presented in the text.