Students explore the biosphere's environments and ecosystems, learning along the way about the plants, animals, resources and natural cycles of our planet. Over the course of lessons 2-6, students use their growing understanding of various environments and the engineering design process to design and create their own model biodome ecosystems - exploring energy and nutrient flows, basic needs of plants and animals, and decomposers. Students learn about food chains and food webs. They are introduced to the roles of the water, carbon and nitrogen cycles. They test the effects of photosynthesis and transpiration. Students are introduced to animal classifications and interactions, including carnivore, herbivore, omnivore, predator and prey. They learn about biomimicry and how engineers often imitate nature in the design of new products. As everyday applications are interwoven into the lessons, students consider why a solid understanding of one's environment and the interdependence within ecosystems can inform the choices we make and the way we engineer our communities.

In this multi-day activity, students explore environments, ecosystems, energy flow and organism interactions by creating a scale model biodome, following the steps of the engineering design process. The Procedure section provides activity instructions for Biodomes unit, lessons 2-6, as students work through Parts 1-6 to develop their model biodome. Subjects include energy flow and food chains, basic needs of plants and animals, and the importance of decomposers. Students consider why a solid understanding of one's environment and the interdependence of an ecosystem can inform the choices we make and the way we engineer our own communities. This activity can be conducted as either a very structured or open-ended design.

Students are presented with a brief history of bridges as they learn about the three main bridge types: beam, arch and suspension. They are introduced to two natural forces tension and compression common to all bridges and structures. Throughout history, and today, bridges are important for connecting people to resources, places and other people. Students become more aware of the variety and value of bridges around us in our everyday lives.

In this activity, students examine how to grow plants the most efficiently. They imagine that they are designing a biofuels production facility and need to know how to efficiently grow plants to use in this facility. As a means of solving this design problem, they plan a scientific experiment in which they investigate how a given variable (of their choice) affects plant growth. They then make predictions about the outcomes and record their observations after two weeks regarding the condition of the plants' stem, leaves and roots. They use these observations to guide their solution to the engineering design problem. The biological processes of photosynthesis and transpiration are briefly explained to help students make informed decisions about planning and interpreting their investigation and its results.

Students learn about the types of possible loads, how to calculate ultimate load combinations, and investigate the different sizes for the beams (girders) and columns (piers) of simple bridge design. Students learn the steps that engineers use to design bridges: understanding the problem, determining the potential bridge loads, calculating the highest possible load, and calculating the amount of material needed to resist the loads.

Students explore the biosphere and its associated environments and ecosystems in the context of creating a model ecosystem, learning along the way about the animals and resources. Students investigate different types of ecosystems, learn new vocabulary, and consider why a solid understanding of one's environment and the interdependence of an ecosystem can inform the choices we make and the way we engineer our communities. This lesson is part of 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 explore the effects of regional geology on bridge foundation, including the variety of soil conditions found beneath foundations. They learn about shallow and deep foundations, as well as the concepts of bearing pressure and settlement.

Students learn about energy flow in food webs, including the roles of the sun, producers, consumers and decomposers in the energy cycle. They model a food web and create diagrams of food webs using their own drawings and/or images from nature or wildlife magazines. Students investigate the links between the sun, plants and animals, building their understanding of the web of nutrient dependency and energy transfer.

Students learn about energy and nutrient flow in various biosphere climates and environments. They learn about herbivores, carnivores, omnivores, food chains and food webs, seeing the interdependence between producers, consumers and decomposers. Students are introduced to the roles of the hydrologic (water), carbon, and nitrogen cycles in sustaining the worlds' ecosystems so living organisms survive. This lesson is part of 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.

In this activity, students design an innovative human shelter that is inspired and informed by an animal structure. Each group is assigned an animal class, and they gather information about shelters used by the animals in that class. After researching the topic and brainstorming ideas, students build small prototypes (models) of the structures. Finally, they present their products, explaining what attribute of the animal structure influenced their design.

This lesson covers the process of photosynthesis and the related plant cell functions of transpiration and cellular respiration. Students will learn how engineers can use the natural process of photosynthesis as an exemplary model of a complex yet efficient process for converting solar energy to chemical energy or distributing water throughout a system.

What do plants need? Students examine the effects of light and air on green plants, learning the processes of photosynthesis and transpiration. Student teams plant seeds, placing some in sunlight and others in darkness. They make predictions about the outcomes and record ongoing observations of the condition of the stems, leaves and roots. Then, several healthy plants are placed in glass jars with lids overnight. Condensation forms, illustrating the process of transpiration, or the release of moisture to the atmosphere by plants.

Students learn about population density within environments and ecosystems. They determine the density of a population and think about why population density and distribution information is useful to engineers for city planning and design as well as for resource allocation.

Students learn about the major factors that comprise the design and construction cost of a modern bridge. Before a bridge design is completed, engineers provide overall cost estimates for construction of the bridge. Students learn about the components that go into estimating the total cost, including expenses for site investigation, design, materials, equipment, labor and construction oversight, as well as the trade-off between a design and its cost.

Students learn about the variety of materials used by engineers in the design and construction of modern bridges. They also find out about the material properties important to bridge construction and consider the advantages and disadvantages of steel and concrete as common bridge-building materials to handle compressive and tensile forces.