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.

Biology is designed for multi-semester biology courses for science majors. It is grounded on an evolutionary basis and includes exciting features that highlight careers in the biological sciences and everyday applications of the concepts at hand. To meet the needs of today’s instructors and students, some content has been strategically condensed while maintaining the overall scope and coverage of traditional texts for this course. Instructors can customize the book, adapting it to the approach that works best in their classroom. Biology also includes an innovative art program that incorporates critical thinking and clicker questions to help students understand—and apply—key concepts.

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

Explain how the binding of a ligand initiates signal transduction throughout a cell
Recognize the role of phosphorylation in the transmission of intracellular signals
Evaluate the role of second messengers in signal transmission

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

Describe how signaling pathways direct protein expression, cellular metabolism, and cell growth
Identify the function of PKC in signal transduction pathways
Recognize the role of apoptosis in the development and maintenance of a healthy organism

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

Describe four types of signaling mechanisms found in multicellular organisms
Compare internal receptors with cell-surface receptors
Recognize the relationship between a ligand’s structure and its mechanism of action

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

Describe how single-celled yeasts use cell signaling to communicate with one another
Relate the role of quorum sensing to the ability of some bacteria to form biofilms

This pathway provides an introduction to cellular mechanisms of communication, highlighting one of the primary mechanisms: signal transduction pathways. For a deeper look at this topic, we recommend the pathway Cell Communication from the OpenStax textbook Biology for AP® Courses.

Genes are turned on and off in many ways. This article covers chemical signal transduction. Article includes animations, pictures, video, biographical information, and quiz questions that are accessed by clicking on buttons along the bottom of the page.

In this step-by-step portrayal discover how cellular communication causes physiological changes during the fight or flight response. In addition to viewing the video, read the scene-by-scene guide to learn what happens when the brain detects danger. [4:25]