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:Define osmosis and explain its role within moleculesExplain why osmoregulation and osmotic balance are important body functionsDescribe active transport mechanismsExplain osmolarity and the way in which it is measuredDescribe osmoregulators or osmoconformers and how these tools allow animals to adapt to different environments

The unit “mole” is used in chemistry as a counting unit for measuring the amount of something. One mole of something has 6.02×1023 units of that thing. The magnitude of the number 6.02×1023 is challenging to imagine. The goal of this lesson is for students to understand just how many particles Avogadro's Number truly represents, or, how big is a mole. This lesson is meant for students currently enrolled in a first or second year chemistry course. This lesson is designed to be completed within one approximately 1 hour class; however, completion of optional activities 4 and 5 may require a longer class period or part of a second class period. This lesson requires only pencil and paper, as the activities suggested in this video place an emphasis on helping students develop their “back of the envelope” estimation skills. In fact, calculators and other measuring devices are explicitly discouraged. However, students may require additional supplies (poster board, colored pencils, markers, crayons, etc.) for the final optional/assessment activity, which involves creating a poster to demonstrate the size of a mole of their favorite macroscopic object.