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 the passage of air from the outside environment to the lungs
Explain how the lungs are protected from particulate matter

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

Describe the cytoskeleton
Compare the roles of microfilaments, intermediate filaments, and microtubules
Compare and contrast cilia and flagella
Summarize the differences among the components of prokaryotic cells, animal cells, and plant cells

Students are introduced to the respiratory system, the lungs and air. They learn about how the lungs and diaphragm work, how air pollution affects lungs and respiratory functions, some widespread respiratory problems, and how engineers help us stay healthy by designing machines and medicines that support respiratory health and function.

Complete descriptions of microtubules and microfilaments. Flip to the following pages to go through a cytoskeleton tutorial with graphics of cross-sections and diagrams. You can test yourself at the end.

This resource provides a detailed diagram of animal, bacterial and plant cells and viral structure. Also included are detailed drawings, with definitions, of each of the cellular organelles.

Article discusses how objects in nature are held together through balanced forces. Scroll midway down to find info on microtubules and microfilaments. Links to excellent electron micrographs.

This scrollable interactive explores the different roles that proteins can play in the cell. Categories of proteins covered include transmembrane proteins, proteins that make up molecular machines like cilia and ribosomes, and enzymes. The four levels of protein structure are also discussed.