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:Understand the synthesis of macromoleculesExplain dehydration (or condensation) and hydrolysis reactions

Students design a temporary habitat for a future classroom pet—a hingeback tortoise. Based on their background research, students identify what type of environment this tortoise needs and how to recreate that environment in the classroom. The students divide into groups and investigate the features of a habitat for a hingeback tortoise. These features include how many holes a temporary habitat may need, the animal’s ideal type of bedding, and how much water is needed to create the necessary humidity level within the tortoise’s environment. Each group communicates and presents this information to the rest of the class after they research, brainstorm, collect and analyze data, and design their final plan.

Students learn about energy and nutrient flow in various biosphere climates and environments. They learn about herbivores, carnivores, omnivores, food chains and food webs, seeing the interdependence between producers, consumers and decomposers. Students are introduced to the roles of the hydrologic (water), carbon, and nitrogen cycles in sustaining the worlds' ecosystems so living organisms survive. This lesson is part of a series of six lessons in which students use their growing understanding of various environments and the engineering design process, to design and create their own model biodome ecosystems.

In a class demonstration, students observe a simple water cycle model to better understand its role in pollutant transport. This activity shows one way in which pollution is affected by the water cycle; it simulates a point source of pollution in a lake and the resulting environmental consequences.

Students apply their understanding of the natural water cycle and the urban "stormwater" water cycle, as well as the processes involved in both cycles to hypothesize how the flow of water is affected by altering precipitation. Student groups consider different precipitation scenarios based on both intensity and duration. Once hypotheses and specific experimental steps are developed, students use both a natural water cycle model and an urban water cycle model to test their hypotheses. To conclude, students explain their results, tapping their knowledge of both cycles and the importance of using models to predict water flow in civil and environmental engineering designs. The natural water cycle model is made in advance by the teacher, using simple supplies; a minor adjustment to the model easily turns it into the urban water cycle model.

Through an overview of the components of the hydrologic cycle and the important roles they play in the design of engineered systems, students' awareness of the world's limited fresh water resources is heightened. The hydrologic cycle affects everyone and is the single most critical component to life on Earth. Students examine in detail the water cycle components and phase transitions, and then learn how water moves through the human-made urban environment. This urban "stormwater" water cycle is influenced by the pervasive existence of impervious surfaces that limit the amount of infiltration, resulting in high levels of stormwater runoff, limited groundwater replenishment and reduced groundwater flow. Students show their understanding of the process by writing a description of the path of a water droplet through the urban water cycle, from the droplet's point of view. The lesson lays the groundwork for rest of the unit, so students can begin to think about what they might do to modify the urban "stormwater" water cycle so that it functions more like the natural water cycle. A PowerPoint® presentation and handout are provided.

Students learn about the techniques engineers have developed for changing ocean water into drinking water, including thermal and membrane desalination. They begin by reviewing the components of the natural water cycle. They see how filters, evaporation and/or condensation can be components of engineering desalination processes. They learn how processes can be viewed as systems, with unique objects, inputs, components and outputs, and sketch their own system diagrams to describe their own desalination plant designs.

Groundwater is one of the largest sources of drinking water, so environmental engineers need to understand groundwater flow in order to tap into this important resource. Environmental engineers also study groundwater to predict where pollution from the surface may end up. In this lesson, students will learn how water flows through the ground, what an aquifer is and what soil properties are used to predict groundwater flow.

Students use a thermal process approach to design, build and test a small-scale desalination plant that is capable of significantly removing the salt content from a saltwater solution. Students use a saltwater circuit to test the efficiency of their model desalination plant and learn how the water cycle is the basis for the thermal processes that drive their desalination plant.

Students learn about the Earth's water cycle, especially about evaporation. Once a dam is constructed, its reservoir becomes a part of the region's natural hydrologic cycle by receiving precipitation, storing runoff water and evaporating water. Although almost impossible to see, and not as familiar to most people as precipitation, evaporation plays a critical role in the hydrologic cycle, and is especially of interest to engineers designing new dams and reservoirs, such as those that Splash Engineering is designing for Thirsty County.