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 how soils are formed
Explain soil composition
Describe a soil profile

Students learn about soil properties and the effect biochar—charcoal used as a soil amendment—has on three soil types, sand, loam and clay. They test the soils’ water retention capability before and after the addition of biochar. During the activity, student teams prepare soil mixtures, make observations (including microscopic examinations), compare soil properties, conduct water retention tests, take and record measurements, and analyze their observations and data. They see how the physical properties of soils—color, texture, and particle size—can be indicators of nutrient content and water retention capabilities to support plant growth. From their findings, they consider biochar’s potential benefits for environmental and agricultural applications, especially in conditions of drought and depleted soils. An activity lab sheet is provided to guide experimental data collection and analysis.