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 how organisms acquire energy in a food web and in associated food chainsExplain how the efficiency of energy transfers between trophic levels affects ecosystem structure and dynamicsDiscuss trophic levels and how ecological pyramids are used to model them

This lesson aims to teach students the difference between food webs and food chains, as well as how toxins in our environment affect large predators through biomagnification. 

By the end of this section, you will be able to:Describe how organisms acquire energy in a food web and in associated food chainsExplain how the efficiency of energy transfers between trophic levels affects ecosystem structure and dynamicsDiscuss trophic levels and how ecological pyramids are used to model them

Methylmercury contamination within fish populations is an important toxin that affect human, animal, and environmental health, serving as a carcinogen (cancer-causing agent) and endocrine-disruptor (compounds that in some way alter the signaling of the hormone system. The impacts of exceeding safe dietary methylmercury levels were tragically made clear in Ontario, Canada, where a First Nations community in Grassy Narrows are living with the consequences of methylmercury poisoning in the fish supply. The fish were contaminated due to the dumping of mercury in the traditional waterways of the First Nation community. In 2016, there were highly publicized protests in Muskrat Falls, Labrador, Canada, where the Inuit people raised direct concerns about the potential for a proposed Nalcor Energy hydroelectric dam, to increase mercury levels in fish in those waters, which are an integral part of their traditional diet. Despite significant protests, the project was completed in 2019 and 41 km were flooded. This module uses these real-world examples as a jumping-off point for exercises that will guide case-study driven discussion on mathematical, biological and ethical concerns.

Students are introduced to the growing worldwide environmental problems that stem from plastic waste. What they learn about microplastics and the typical components of the U.S. water treatment process prepares them to conduct three engaging associated activities. During the lesson, students become more aware of the pervasiveness and value of plastic as well as the downstream pollution and health dangers. They learn how plastic materials don’t go away, but become microplastic pollution that accumulates in water resources as well as human and other animal bodies. They examine their own plastic use, focusing on what they discard daily, and think about better ways to produce or package those items to eliminate or reduce their likelihood of ending up as microplastic pollution. A concluding writing assignment reveals their depth of comprehension. The lesson is enhanced by arranging for a local water treatment plant representative to visit the class for Qs and As. In three associated activities, students design/test microplastic particle filtering methods for commercial products, create mini wastewater treatment plant working models that remove waste and reclaim resources from simulated wastewater, and design experiments to identify the impact of microplastics on micro-invertebrates.