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:

Explain adaptive immunity
Compare and contrast adaptive and innate immunity
Describe cell-mediated immune response and humoral immune response
Describe immune tolerance

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

Explain cross-reactivity
Describe the structure and function of antibodies
Discuss antibody production

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

Describe hypersensitivity
Define autoimmunity

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

Describe physical and chemical immune barriers
Explain immediate and induced innate immune responses
Discuss natural killer cells
Describe major histocompatibility class I molecules
Summarize how the proteins in a complement system function to destroy extracellular pathogens

Dr. Stephen O'Brien of the National Cancer Institute discovers a 700-year-old mutation that makes a person resistant to HIV infection. From Evolution: "Evolutionary Arms Race."

Dr. Stephen O'Brien of the National Cancer Institute discovers a 700-year-old mutation that makes a person resistant to HIV infection. From Evolution: "Evolutionary Arms Race."

In this video segment from 'Greater Boston,' Liz Lombard describes her struggle with a painful, progressive autoimmune disease called scleroderma. Scleroderma is rare, so Lombard was surprised to learn that other people in her South Boston neighborhood also had the disease. Health officials explain that there is a genetic predisposition to scleroderma, and there may be environmental factors involved as well. However, officials don't know whether this particular cluster is a result of environmental hazards or simply a coincidence. Includes background essay and discussion questions. [3:22]

When do the actions of one branch of the federal government unconstitutionally intrude upon the powers of another branch? This article surveys the history of this question in historic Supreme Court cases.

This lesson describes the major components and functions of the immune system and the role of engineers in keeping the body healthy (e.g., vaccinations and antibiotics, among other things). This lesson also discusses how an astronaut's immune system is suppressed during spaceflight due to stress and other environmental factors.

Read a passage about our immune system and answer the follow-up questions.

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

Although repeatedly exposed to HIV, Steve Crohn's blood cells were never infected. Dr. David Ho investigates in this video segment from NOVA: "Surviving AIDS."

In this simulation the learner will design a sequence of experiments to
generate a coronavirus vaccine.

In this video segment from The Secret of Life, watch as a virus attacks a cell, and learn how the immune system reacts to this onslaught. Includes background reading material and discussion questions. [1:40]

Learn about the human body's second line of defense against pathogens, innate immunity. [5:24]

This Nobel E-Museum site provides an autobiography and a very detailed description of Mr. Tonegawa's work for which he received the Nobel Prize in 1987.

Students modify a provided App Inventor code to design their own diseases. This serves as the evolution step in the software/systems design process. The activity is essentially a mini design cycle in which students are challenged to design a solution to the modification, implement and test it using different population patterns The result of this process is an evolution of the original app.

Learn how vaccines help the immune system protect people against diseases in this video. [3:37] The immune system is a natural defense system that uses biological processes to fight invaders such as germs. Vaccines introduce a weakened germ to the body so that the immune system learns how to fight it and is prepared for a future invasion. Animations illustrate how white blood cells and antibodies fight germs, and show how vaccines arm the immune system with memory cells. Vaccines prevent disease epidemics and are especially important for babies, whose immune systems are immature and vulnerable to infection. Support materials are provided.