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.

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.

Students use the same method as in the activity from lesson 2 of this unit to explore the magnetism due to electric current instead of a permanent magnet. Students use a compass and circuit to trace the magnetic field lines induced by the electric current moving through the wire. Students develop an understanding of the effect of the electrical current on the compass needle through the induced magnetic field and understand the complexity of a three dimensional field system.

Students are challenged to design a method for separating steel from aluminum based on magnetic properties as is frequently done in recycling operations. To complicate the challenge, the magnet used to separate the steel must be able to be switched off to allow for the recollection of the steel. Students must ultimately design, test, and present an effective electromagnet.

Students explore the definition of a function by playing an interactive game called "Club Function." The goal of the game is to be in the club! With students each assigned to be either a zebra or a rhinoceros, they group themselves according to the "rules" of the club function. After two minutes, students freeze in their groups, and if they are not correctly following the rules of the club function, then they are not allowed into the "club." Through this activity students come to understand that one x-coordinate can only have one corresponding y-coordinate while y-coordinates can have many x-coordinates that correspond to it.

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.

The computer program's simulation of a Sonoran desert community should ultimately strengthen the student's comprehension of what is required for a natural ecosystem to sustain itself (remain in balance). This computer simulation program has great flexibility. It allows the student to manipulate the population numbers of five Sonoran Desert species. A species natural history attachment provides vital information for the students to familiarize themselves with each species' behaviors, its niche and food resource needs. The program includes two producers, the Saguaro cactus and the Ironwood Tree. It also includes 3 consumers, but their interactions both toward the producers and each other differ. The community's ability to remain in balance and sustain all five species so that none die out rests on the student's assessment skills enabling him to correctly identify these dependencies. The student learns by trial and error as he continues to fine tune the ecosystem that he maintains stewardship of.

Students use simple household materials, such as PVC piping and compact mirrors, to construct models of laser-based security systems. The protected object (a "mummified troll" or another treasure of your choosing) is placed "on display" in the center of the modeled room and protected by a laser system that utilizes a laser beam reflected off mirrors to trigger a light trip sensor with alarm.

Is the food chain shown above accurate? Does the first link depict a producer, the second link a herbivore, and the third link an omnivore / carnivore? Students must correctly determine whether a species is a producer or consumer, and what type of consumer; herbivore, omnivore, or carnivore. Students are provided with a list of Sonoran Desert species and asked to construct, within their groups, several food chains. These food chains are then be used to construct a food web. In order to complete this activity, students must first research the individual species to understand their feeding habits.

A brief refresher on the Cartesian plane includes how points are written in (x, y) format and oriented to the axes, and which directions are positive and negative. Then students learn about what it means for a relation to be a function and how to determine domain and range of a set of data points.

Students are challenged to design a permanent guest village within the Saguaro National Park in Arizona. The design must provide a true desert experience to visitors while emphasizing sustainable design, protection of the natural environment, and energy and resource conservation. To successfully address and respond to this challenge, students must acquire an understanding of desert ecology, environmental limiting factors, species adaptations and resource utilization. Following theintroduction, students generate ideas and consider the knowledge required to complete the challenge. The lectures and activities that follow serve to develop this level of comprehension. To introduce the concepts of healthy ecosystems, biomimetics and the importance of sustainable environmental design, students watch three video clips of experts. These clips provide direction for student research and challenge design solutions.

The Challenge Question of the Legacy Cycle draws the student into considering the engineering ingenuity of nature. It will force him to analyze, appreciate and understand the wisdom of these designs as the student team focuses on meeting each of the challenge's requirements. The student is asked, with his team members, to envision a sustainable design for a future guest village within the Saguaro National Park, outside of Tucson, Arizona. What issues need to be addressed to support the comforts of park visitors without compromising the natural resources or endangering the endemic species of the area? A deeper scope of application will reveal extensions of this design in the incorporation of urban planning and systems design. It also strengthens the concept of manufacturing and building without producing waste or pollution.

Students are introduced to the unit challenge: To develop a painless means of identifying cancerous tumors. Solving the challenge depends on an understanding of the properties of stress and strain. After learning the challenge question, students generate ideas and consider the knowledge required to solve the challenge. Then they read an expert's opinion on ultrasound imaging and the potentials for detecting cancerous tumors. This interview helps to direct student research and learning towards finding a solution.

Following the steps of the iterative engineering design process, student teams use what they learned in the previous lessons and activity in this unit to research and choose materials for their model heart valves and test those materials to compare their properties to known properties of real heart valve tissues. Once testing is complete, they choose final materials and design and construct prototype valve models, then test them and evaluate their data. Based on their evaluations, students consider how they might redesign their models for improvement and then change some aspect of their models and retest aiming to design optimal heart valve models as solutions to the unit's overarching design challenge. They conclude by presenting for client review, in both verbal and written portfolio/report formats, summaries and descriptions of their final products with supporting data.

Students use a compass and a permanent magnet to trace the magnetic field lines produced by the magnet. By positioning the compass in enough spots around the magnet, the overall magnet field will be evident from the collection of arrows representing the direction of the compass needle. In activities 3 and 4 of this unit, students will use this information to design a way to solve the grand challenge of separating metal for a recycling company.

As part of the engineering design process to create testable model heart valves, students learn about the forces at play in the human body to open and close aortic valves. They learn about blood flow forces, elasticity, stress, strain, valve structure and tissue properties, and Young's modulus, including laminar and oscillatory flow, stress vs. strain relationship and how to calculate Young's modulus. They complete some practice problems that use the equations learned in the lesson mathematical functions that relate to the functioning of the human heart. With this understanding, students are ready for the associated activity, during which they research and test materials and incorporate the most suitable to design, build and test their own prototype model heart valves.

The grand challenge for this legacy cycle unit is for students to design a way to help a recycler separate aluminum from steel scrap metal. In previous lessons, they have looked at how magnetism might be utilized. In this lesson, students think about how they might use magnets and how they might confront the problem of turning the magnetic field off. Through the accompanying activity students explore the nature of an electrically induced magnetic field and its applicability to the needed magnet.

Students are presented with a hypothetical scenario that delivers the unit's Grand Challenge Question: To apply an understanding of nanoparticles to treat, detect and protect against skin cancer. Towards finding a solution, they begin the research phase by investigating the first research question: What is electromagnetic energy? Students learn about the electromagnetic spectrum, ultraviolet radiation (including UVA, UVB and UVC rays), photon energy, the relationship between wave frequency and energy (c = λν), as well as about the Earth's ozone-layer protection and that nanoparticles are being used for medical applications. The lecture material also includes information on photo energy and the dual particle/wave model of light. Students complete a problem set to calculate frequency and energy.

In this activity, the students will complete the grand challenge and design an electromagnet to separate steel from aluminum for the recycler. In order to do this, students compare the induced magnetic field of an electric current with the magnetic field of a permanent magnet and must make the former look like the latter. They discover that looping the current produces the desired effect and find ways to further strengthen the magnetic field.