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 the unique anatomical and morphological features of flatworms, rotifers, Nemertea, mollusks, and annelidsDescribe the development of an extracoelomic cavityDiscuss the advantages of true body segmentationExplain the key features of Platyhelminthes and their importance as parasitesDescribe the features of animals classified in phylum Annelida

This 12-minute video lesson looks at the structure of the earth. The discussion includes the crust, mantle, core, lithosphere, asthenosphere, mesosphere, outer core, and inner core. [Cosmology and Astronomy playlist: Lesson 50 of 85]

This 10-minute video lesson covers the structure of the Earth: The crust, mantle, and core. [Cosmology and Astronomy playlist: Lesson 44 of 85]