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 prions and their basic properties
Define viroids and their targets of infection

Explains the body's first line of defense against pathogens, such as the skin and body fluids.

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This study guide on the immune system covers key terminology and the different lines of defense the human body has to protect itself against pathogens. It is available for download with free registration.

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Covers the role of the lymphatic system in the immune response.

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Paul Andersen explains how your body protects itself from invading viruses and bacteria. He starts by describing the nonspecific immune responses of skin and inflammation. He then explains how we use antibodies to disrupt the function of antigens and mark them for destruction. [13:46]

Learn about the human body's immune response to pathogens.

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Examine how vaccines generate immune responses against pathogens in the body by creating six vaccines in this virtual laboratory.

Comprehensive description of the environmental benefits of composting solid waste. Complete directions for composting, detailed description of composting chemistry, suggestions for applications of humus, question and answer page, scientific activities for school children regarding composting benefits and physics involved, comprehensive table of compostable materials, directions for building many types of home composting bins, plus links to other waste management information.

Use this website to find out about water quality issues anywhere in the U.S.A. where water studies have been conducted by the U.S. Geological Survey.

This U.S. Geological Survey website offers a short article then lists topics that are linked to brief articles that describe that particular topic's effect on water quality in urban areas. Click Home to access the site in Spanish.