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

This 19-minute video lesson looks at diffusion and osmosis. [Biology playlist: Lesson 36 of 71].

By the end of this section, you will be able to:Explain why and how passive transport occursUnderstand the processes of osmosis and diffusionDefine tonicity and describe its relevance to passive transport

Learn about diffusion, osmosis, and concentration gradients and why these are important to cells. Created by Sal Khan.

This course is a project-based introduction to manipulating and characterizing cells and biological molecules using microfabricated tools. It is designed for first year undergraduate students. In the first half of the term, students perform laboratory exercises designed to introduce (1) the design, manufacture, and use of microfluidic channels, (2) techniques for sorting and manipulating cells and biomolecules, and (3) making quantitative measurements using optical detection and fluorescent labeling In the second half of the term, students work in small groups to design and test a microfluidic device to solve a real-world problem of their choosing. Includes exercises in written and oral communication and team building.

Principles of mass transport and electrical signal generation for biological membranes, cells, and tissues. Mass transport through membranes: diffusion, osmosis, chemically mediated, and active transport. Electric properties of cells: ion transport; equilibrium, resting, and action potentials. Kinetic and molecular properties of single voltage-gated ion channels. Laboratory and computer exercises illustrate the concepts. For juniors and seniors. Students engage in extensive written and oral communication exercises.

Example calculating the water potential of potato squares based on placing them in various concentrations of sucrose solutions.