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:Describe how viruses were first discovered and how they are detectedDiscuss three hypotheses about how viruses evolvedRecognize the basic shapes of virusesUnderstand past and emerging classification systems for viruses

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.

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.

Students learn about water poverty and how water engineers can develop appropriate solutions to a problem that is plaguing nearly a sixth of the world's population. Students follow the engineering design process to design a gravity-fed water system. They choose between different system parameters such as pipe sizes, elevation differentials between entry and exit pipes, pipe lengths and tube locations to find a design that provides the maximum flow and minimum water turbidity (cloudiness) at the point of use. In this activity, students play the role of water engineers by designing and building model gravity-fed water systems, learning the key elements necessary for viable projects that help improve the lives people in developing communities.

This courses focuses on the fundamentals of tissue and organ response to injury from a molecular and cellular perspective. There is a special emphasis on disease states that bridge infection, inflammation, immunity, and cancer. The systems approach to pathophysiology includes lectures, critical evaluation of recent scientific papers, and student projects and presentations. This term, we focus on hepatocellular carcinoma (HCC), chronic-active hepatitis, and hepatitis virus infections. In addition to lectures, students work in teams to critically evaluate and present primary scientific papers.

Student teams practice water quality analysis through turbidity measurement and coliform bacteria counts. They use information about water treatment processes to design prototype small-scale water treatment systems and test the influent (incoming) and effluent (outgoing) water to assess how well their prototypes produce safe water to prevent water-borne illnesses.

Students simulate the spread of a virus such as HIV through a population by "sharing" (but not drinking) the water in a plastic cup with several classmates. Although invisible, the water in a few of the cups has already be tainted with the "virus" (sodium carbonate). After all the students have shared their liquids, the contents of the cups are tested for the virus with phenolphthalein, a chemical that causes a striking color change in the presence of sodium carbonate. Students then set about trying to determine which of their classmates were the ones originally infected with the virus.

Students learn how viruses invade host cells and hijack the hosts' cell-reproduction mechanisms in order to make new viruses, which can in turn attack additional host cells. Students also learn how the immune system responds to a viral invasion, eventually defeating the viruses -- if all goes well. Finally, they consider the special case of HIV, in which the virus' host cell is a key component of the immune system itself, severely crippling it and ultimately leading to AIDS. The associated activity, Tracking a Virus, sets the stage for this lesson with a dramatic simulation that allows students to see for themselves how quickly a virus can spread through a population, and then challenges students to determine who the initial bearers of the virus were.