Two lessons and their associated activities explore cellular respiration and population growth in yeasts. Yeast cells are readily obtained and behave predictably, so they are very appropriate to use in middle school classrooms. In the first lesson, students are introduced to yeast respiration through its role in the production of bread and alcoholic beverages. A discussion of the effects of alcohol on the human body is used both as an attention-getting device, and as a means to convey important information at an impressionable age. In the associated activity, students set up a simple way to indirectly observe and quantify the amount of respiration occurring in yeast-molasses cultures. Based on questions that arise from this activity, in the second lesson students work in small groups as they design and execute their own experiments to determine how environmental factors affect yeast population growth.

Students are introduced to the "Walk the Line" challenge question. They write journal responses to the question and brainstorm what information they need to answer the question. Ideas are shared with the class (or in pairs and then to the class, if class size is large). Then students read an interview with an engineer to gain a professional perspective on linear data sets and best-fit lines. Students brainstorm for additional ideas and add them to the list. With the teacher's guidance, students organize the ideas into logical categories of needed knowledge.

This lesson begins with an activity in which students induce EMF in a coil of wire using magnetic fields. Then, demonstrations on Eddy currents show how a magnetic field can slow magnets just as Eddy currents are used to slow large trains. There is then a demonstration in which a loop "jumps" because of a changing magnetic field. Finally, formal lecture reviews the cross product with respect to magnetic force and introduces magnetic flux, Faraday's law of Induction, Lenz's Law, Eddy currents, motional EMF and Induced EMF.

This lesson introduces the concepts of wavelength and amplitude in transverse waves. In the associated activity, students will use ropes and their bodies to investigate different wavelengths and amplitudes.

Students are introduced to chemical engineering and learn about its many different applications. They are provided with a basic introduction to matter and its different properties and states. An associated hands-on activity gives students a chance to test their knowledge of the states of matter and how to make observations using their five senses: touch, smell, sound, sight and taste.

Students are introduced to several key concepts of electronic circuits. They learn about some of the physics behind circuits, the key components in a circuit and their pervasiveness in our homes and everyday lives. Students learn about Ohm's Law and how it is used to analyze circuits.

Hydropower generation is introduced to students as a common purpose and benefit of constructing dams. Through an introduction to kinetic and potential energy, students come to understand how a dam creates electricity. They also learn the difference between renewable and non-renewable energy.

Students investigate decomposers and the role of decomposers in maintaining the flow of nutrients in an environment. Students also learn how engineers use decomposers to help clean up wastes in a process known as bioremediation. This lesson concludes a series of six lessons in which students use their growing understanding of various environments and the engineering design process, to design and create their own model biodome ecosystems.

Students learn about a special branch of engineering called bioremediation, which is the use of living organisms to aid in the clean-up of pollutant spills. Students learn all about bioremediation and see examples of its importance. In the associated activity, students conduct an experiment and see bioremediation in action!

In this lesson, students continue their education on cells in the human body. They discuss stem cells and how engineers are involved in the research of stem cell behavior. They learn about possible applications of stem cell research and associated technologies, such as fluorescent dyes for tracking the replication of specific cells.

Polymers are a vital part of our everyday lives and nearly all consumer products have a plastic component of some variation. Students explore the basic characteristics of polymers through the introduction of two polymer categories: thermoplastics and thermosets. During teacher demos, students observe the unique behaviors of thermoplastics. The fundamentals of thermoset polymers are discussed, preparing them to conduct the associated activity in which they create their own thermoset materials and mechanically test them. At the conclusion of this lesson-activity pair, students understand the basics of thermoplastics and thermosets, which may entice their interest in polymer engineering.

As a continuation of the theme of potential and kinetic energy, this lesson introduces the concepts of momentum, elastic and inelastic collisions. Many sports and games, such as baseball and ping-pong, illustrate the ideas of momentum and collisions. Students explore these concepts by bouncing assorted balls on different surfaces and calculating the momentum for each ball.

This activity provides an introduction to natural selection and the role of genetic variation by asking students to analyze illustrations of rock pocket mouse populations (dark/light fur) on different color substrates in the Sonoran Desert (light/dark) over time. Based on this evidence, and what they learn about variation and natural selection in the accompanying short film, students use this evidence to explain the change in the rock pocket mouse populations on the lava flow (dark substrate) over time. This is one of several classroom activities, focusing on related topics and varying in complexity, built around the short film. This ten minute film shows adaptive changes in rock pocket mouse populations, demonstrating the process of natural selection and can be accessed at http://www.hhmi.org/biointeractive/making-fittest-natural-selection-and-adaptation. The film is also available as an interactive video with embedded questions, which test students’ understanding as they watch the film.

This classroom activity for high school students uses a collection of Hubble Space Telescope images of galaxies in the Coma Cluster. Students study galaxy classification and the evolution of galaxies in dense clustered environments.

Have you ever wondered why it takes such a long period of time for NASA to build space exploration equipment? What is involved in manufacturing and building a rover for the Red Planet? During this lesson, students will discover the journey that a Mars rover embarks upon after being designed by engineers and before being prepared for launch. Students will investigate the fabrication techniques, tolerance concepts, assembly and field-testing associated with a Mars exploratory rover.

Students continue an examination of logarithms in the Research and Revise stage by studying two types of logarithms—common logarithms and natural logarithm. In this study, they take notes about the two special types of logarithms, why they are useful, and how to convert to these forms by using the change of base formula. Then students see how these types of logarithms can be applied to solve exponential equations. They compute a set of practice problems and apply the skills learned in class.

Students learn about complex networks and how to represent them using graphs. They also learn that graph theory is a useful mathematical tool for studying complex networks in diverse applications of science and engineering, such as neural networks in the brain, biochemical reaction networks in cells, communication networks, such as the internet, and social networks. Topics covered include set theory, defining a graph, as well as defining the degree of a node and the degree distribution of a graph.

Students learn how the total solar irradiance hitting a photovoltaic (PV) panel can be increased through the use of a concentrating device, such as a reflector or lens. This is the final lesson in the Photovoltaic Efficiency unit and is intended to accompany a fun design project (see the associated Concentrating on the Sun with PVs activity) to wrap up the unit. However, it can be completed independently of the other unit lessons and activities.