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 plants absorb energy from sunlightDescribe short and long wavelengths of lightDescribe how and where photosynthesis takes place within a plant

Students learn a simple technique for quantifying the amount of photosynthesis that occurs in a given period of time, using a common water plant (Elodea). They can use this technique to compare the amounts of photosynthesis that occur under conditions of low and high light levels. Before they begin the experiment, however, students must come up with a well-worded hypothesis to be tested. After running the experiment, students pool their data to get a large sample size, determine the measures of central tendency of the class data, and then graph and interpret the results.

Through a teacher-led discussion, students realize that the food energy plants obtain comes from sunlight via the plant process of photosynthesis. They learn what photosynthesis is, at an age-appropriate level of detail and vocabulary, and then begin to question how we know that photosynthesis occurs, if we can't see it happening. Elodea is a common water plant that students can use to directly observe evidence of photosynthesis. When Elodea is placed in a glass beaker near a good light source, bubbles of oxygen will be released as products of photosynthesis. By counting the number of bubbles that rise to the surface in a five-minute period, students can compare the photosynthetic activity of Elodea in the presence of high and low light levels.

Students are introduced to sound energy concepts and how engineers use sound energy. Through hands-on activities and demonstrations, students examine how we know sound exists by listening to and seeing sound waves. They learn to describe sound in terms of its pitch, volume and frequency. They explore how sound waves move through liquids, solids and gases. They also identify the different pitches and frequencies, and create high- and low-pitch sound waves.

Students learn how the sun can be used for energy. They learn about passive solar heating, lighting and cooking, and active solar engineering technologies (such as photovoltaic arrays and concentrating mirrors) that generate electricity. Students investigate the thermal energy storage capacities of test materials. They learn about radiation and convection as they build a model solar water heater and determine how much it can heat water in a given amount of time. In another activity, students build and compare the performance of four solar cooker designs. In an associated literacy activity, students investigate how people live "off the grid" using solar power.

Students are introduced to the physical concept of the colors of rainbows as light energy in the form of waves with distinct wavelengths, but in a different manner than traditional kaleidoscopes. Looking at different quantum dot solutions, they make observations and measurements, and graph their data. They come to understand how nanoparticles interact with absorbing photons to produce colors. They learn the dependence of particle size and color wavelength and learn about real-world applications for using these colorful liquids.

Working as if they were engineers, students design and construct model solar sails made of aluminum foil to move cardboard tube satellites through “space” on a string. Working in teams, they follow the engineering design thinking steps—empathize, define, ideate, prototype, test, redesign—to design and test small-scale solar sails for satellites and space probes. During the process, learn about Newton’s laws of motion and the transfer of energy from wave energy to mechanical energy. A student activity worksheet is provided.

Student groups rotate through four stations to examine light energy behavior: refraction, magnification, prisms and polarization. They see how a beam of light is refracted (bent) through various transparent mediums. While learning how a magnifying glass works, students see how the orientation of an image changes with the distance of the lens from its focal point. They also discover how a prism works by refracting light and making rainbows. And, students investigate the polar nature of light using sunglasses and polarized light film.

Student teams conduct an experiment that uses gold nanoparticles as sensors of chemical agents to determine which of four sports drinks has the most electrolytes. In this way, students are introduced to gold nanoparticles and their influence on particle or cluster size and fluorescence. They also learn about surface plasmon resonance phenomena and how it applies to gold nanoparticle technologies, which touches on the basics of the electromagnetic radiation spectrum, electrolyte chemistry and nanoscience. Using some basic chemistry and physics principles, students develop a conceptual understanding of how gold nanoparticles function. They also learn of important practical applications in biosensing.

With an introduction to the ideas of energy, students discuss specific types of energy and the practical sources of energy. Hands-on activities help them identify types of energy in their surroundings and enhance their understanding of energy.