Few people are aware of how crucial the sense of smell is to identifying foods, or the adaptive value of being able to identify a food as being familiar and therefore safe to eat. In this lesson and activity, students conduct an experiment to determine whether or not the sense of smell is important to being able to recognize foods by taste. The teacher leads a discussion that allows students to explore why it might be adaptive for humans and other animals to be able to identify nutritious versus noxious foods. This is followed by a demonstration in which a volunteer tastes and identifies a familiar food, and then attempts to taste and identify a different familiar food while holding his or her nose and closing his or her eyes. Then, the class develops a hypothesis and a means to obtain quantitative results for an experiment to determine whether students can identify foods when the sense of smell has been eliminated.

Students are presented with a short lesson on the difference between cohesive forces (the forces that hold water molecules together and create surface tension) and adhesive forces (the forces that causes water to "stick" to solid surfaces. The interaction between cohesive forces and adhesive forces causes the well-known capillary action. Students are also introduced to examples of capillary action found in nature and in our day-to-day lives.

In the exploration of ways to use solar energy, students investigate the thermal energy storage capacities of different test materials to determine which to use in passive solar building design.

Students are introduced to the concept of energy cycles by learning about the carbon cycle. They will learn how carbon atoms travel through the geological (ancient) carbon cycle and the biological/physical carbon cycle. Students will consider how human activities have disturbed the carbon cycle by emitting carbon dioxide into the atmosphere. They will discuss how engineers and scientists are working to reduce carbon dioxide emissions. Lastly, students will consider how they can help the world through simple energy conservation measures.

Students learn how the aerodynamics and rolling resistance of a car affect its energy efficiency through designing and constructing model cars out of simple materials. As the little cars are raced down a tilted track (powered by gravity) and propelled off a ramp, students come to understand the need to maximize the energy efficiency of their cars. The most energy-efficient cars roll down the track the fastest and the most aerodynamic cars jump the farthest. Students also work with variables and plot how a car's speed changes with the track angle.

In some cities, especially large cities such as Los Angeles or Mexico City, visible air pollution is a major problem, both for human health and the environment. A variety of sources contribute to air pollution, but personal vehicles account for one of the main sources. Though each car has relatively low emissions when compared to vehicles of the 1970s, there are so many more cars on the road now that their emissions play a large role in overall pollution. In this activity, students think about alternate ways to power a vehicle to reduce emissions. Student teams design an eco-friendly car using the engineering design process, and make a presentation to showcase their product.

Students observe Pascal's law, Archimedes' principle and the ideal gas law as a Cartesian diver moves within a closed system. The Cartesian diver is neutrally buoyant and begins to sink when an external pressure is applied to the closed system. A basic explanation and proof of this process is provided in this activity, and supplementary ideas for more extensive demonstrations and independent group activities are presented.

Students consider the Earth's major types of landforms such as mountains, rivers, plains, hills, canyons, oceans and plateaus. Student teams build three-dimensional models of landscapes, depicting several of these landforms. Once the models are built, they act as civil and transportation engineers to design and build roads through the landscapes they have created. The worksheet is provided in English and Spanish.

Working in teams of three, students perform quantitative observational experiments on the motion of LEGO MINDSTORMS(TM) NXT robotic vehicles powered by the stored potential energy of rubber bands. They experiment with different vehicle modifications (such as wheel type, payload, rubber band type and lubrication) and monitor the effects on vehicle performance. The main point of the activity, however, is for students to understand that through the manipulation of mechanics, a rubber band can be used in a rather non-traditional configuration to power a vehicle. In addition, this activity reinforces the idea that elastic energy can be stored as potential energy.

Students learn about power generation using river currents. A white paper is a focused analysis often used to describe how a technology solves a problem. In this literacy activity, students write a simplified version of a white paper on an alternative electrical power generation technology. In the process, they develop their critical thinking skills and become aware of the challenge and promise of technological innovation that engineers help to make possible. This activity is geared towards fifth grade and older students and computer capabilities are required. Some portions of the activity may be appropriate with younger students. CAPTION: Upper Left: Trey Taylor, President of Verdant Power, talks about green power with a New York City sixth-grade class. Lower Left: Verdant Power logo. Center: Verdant Power's turbine evaluation vessel in New York's East River. In the background is a conventional power plant. Upper Right: The propeller-like turbine can be raised and lowered from the platform of the turbine evaluation vessel. Lower Right: Near the East River, Mr. Taylor explains to the class how water currents can generate electric power.

Students observe the relationship between the angle of a catapult (a force measurement) and the flight of a cotton ball. They learn how Newton's second law of motion works by seeing directly that F = ma. When they pull the metal "arm" back further, thus applying a greater force to the cotton ball, it causes the cotton ball to travel faster and farther. Students also learn that objects of greater mass require more force to result in the same distance traveled by a lighter object.

Bycatch can be defined as the act of unintentionally catching certain living creatures using fishing gear. A bycatched species is distinguished from a target species (the animal the gear is intended to catch) because it is not sold or used. Marine mammals (whales, dolphins, porpoises), seabirds, sea turtles and unwanted or undersized fish are some examples of animals caught as by-catch The incidental capture of these animals can significantly reduce their populations. The most well known example of by-catch may be the unintentional mortality of spotted and spinner dolphins in the tuna fishing industry. "Dolphin-Safe" tuna was a result of this interaction (Be prepared to discuss how this came about with students, as it is something close to their daily lives). One important aspect to consider when discussing this issue is that laws protect some of the animals caught as by-catch (Marine Mammal Protection Act and Endangered Species Act). In this lesson, students will first be shown pictures of entangled marine animals and will discuss the definition of by-catch This will lead to discussions on why by-catching exists, how it impacts specific animals as well as humans, whether the students believe it is an important issue, and how by-catch can be reduced.

In this lesson, the students look at the components of cells and their functions. The lesson focuses on the difference between prokaryotic and eukaryotic cells. Each part of the cell performs a specific function that is vital for the cell's survival. Bacteria are single-celled organisms that are very important to engineers. Engineers can use bacteria to break down toxic materials in a process called bioremediation, and they can also kill or disable harmful bacteria through disinfection.

Students color-code a schematic of a cell and its cell membrane structures. Then they complete the "Build-a-Membrane" activity found at http://learn.genetics.utah.edu. This reinforces their understanding of the structure and function of animal cells, and shows them the importance of being able to construct a tangible model of something that is otherwise difficult to see.

The final activity of this unit, which integrates the Keepers of the Gate unit through the Go Public challenge, involves students taking part in experimental design. They design a lab that answers the challenge question: "You are spending the night with your grandmother when your throat starts to feel sore. Your grandma tells you to gargle with salt water and it will feel much better. Thinking this is an old wive's tale, you scoff, but when you try it later that night it works! Why?" Students must have their plan approved by the instructor before they begin. A formal lab write-up is due as part of the laboratory investigation.

Students learn about the different structures that comprise cell membranes, fulfilling part of the Research and Revise stages of the legacy cycle. They view online animations of cell membrane dynamics (links provided). Then they observe three teacher demonstrations that illustrate diffusion and osmosis concepts, as well as the effect of movement through a semi-permeable membrane using Lugol's solution.

In this unit, students look at the components of cells and their functions and discover the controversy behind stem cell research. The first lesson focuses on the difference between prokaryotic and eukaryotic cells. In the second lesson, students learn about the basics of cellular respiration. They also learn about the application of cellular respiration to engineering and bioremediation. The third lesson continues students' education on cells in the human body and how (and why) engineers are involved in the research of stem cell behavior.

In this lesson, students learn about the basics of cellular respiration. They also learn about the application of cellular respiration to engineering and bioremediation. And, students are introduced to the process of bioremediation and several examples of how bioremediation is used during the cleanup of environmental contaminants.

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.

Student groups compete to design a process that removes the most iron from fortified cereal. Students experiment with different materials using what they know about iron, magnets and forces to design the best process for removing iron from the cereal samples.