Biology 2e is designed to cover the scope and sequence requirements of a typical two-semester biology course for science majors. The text provides comprehensive coverage of foundational research and core biology concepts through an evolutionary lens. Biology includes rich features that engage students in scientific inquiry, highlight careers in the biological sciences, and offer everyday applications. The book also includes various types of practice and homework questions that help students understand—and apply—key concepts. The 2nd edition has been revised to incorporate clearer, more current, and more dynamic explanations, while maintaining the same organization as the first edition. Art and illustrations have been substantially improved, and the textbook features additional assessments and related resources.

By the end of this section, you will be able to do the following:

Describe how red and blue light affect plant growth and metabolic activities
Discuss gravitropism
Understand how hormones affect plant growth and development
Describe thigmotropism, thigmonastism, and thigmogenesis
Explain how plants defend themselves from predators and respond to wounds

Paul Andersen explains how the behavior of various organisms is shaped by natural selection. The action of phototropism and the timing of photoperiodism have both been shaped by the relative availability of light. Courtship in the bower bird determines the success of offspring. [9:02]