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:Explain how vacuoles, present in microorganisms, work to excrete wasteDescribe the way in which flame cells and nephridia in worms perform excretory functions and maintain osmotic balanceExplain how insects use Malpighian tubules to excrete wastes and maintain osmotic balance

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 resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"Many animals live in symbiosis with beneficial microbes. These beneficial associations are stable over time because of partner fidelity between the animals and their microbes over multiple generations. Long-term fidelity in terrestrial host animals is well understood, but fidelity in marine symbioses, particularly in hosts with multiple symbionts, is understudied. To learn more, researchers recently examined partner fidelity between the gutless marine worm Olavius algarvensis and its seven bacterial symbionts. Fidelity varied considerably across the seven symbionts. Fidelity was highest for the two sulphur-oxidizing symbionts that provide the worms with most of their nutrition. In contrast, fidelity was lower or non-existent for other less-abundant, nutritionally less important symbionts. This variability in fidelity was unexpected, because O. algarvensis pass their symbionts directly to their offspring from one generation to the next..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.