In Investigation One, students perform experiments to understand the concepts of food chains and the food webs. They gather data and do calculations to determine the total biomass in an ecosystem.

In Investigation Two, students perform experiments that introduce differences between food chains and food webs. They concentrate on the relationship between producers and consumers, discovering that changes in producers affect consumers in both food chains and food webs. Analysis of experimental results leads students to understand the interdependence of organisms within ecosystems.

Students perform experiments in Investigation Three that introduce them to the concept of adaptation to an ecosystem. They discover that certain types of structures are more suited for one ecosystem than another and that therefore one might expect that plants and animals living in specific ecosystems may have similar structural adaptations for their survival.

Through experimentation, students explore the impact of environmental changes on the primary food supply in an ecosystem. Through analysis of experimental data, they discover that changes in food supply directly affect animal consumers and that consumers are in competition with each other to survive in a changing ecosystem. They also are introduced to the concept of extinction and the fossil record.

In Investigation Five, students conclude their exploration of the environment by investigating the impact of pollution on an entire ecosystem and the animals that live there. They discover, through experimentation, the impact of pollution on reducing the number of plant producers and its subsequent impact on herbivore consumers and their carnivorous predators. Students find that animals may not even know that they are consuming contaminated food. They also examine how toxic pollutants may pass up the food chain from contaminated plants to herbivore consumers to the carnivores that feed on them.

In this Performance Assessment, students are required to combine conceptual knowledge regarding extinction and the structure of a fossil record with knowledge of the effect of environmental changes and the amount of a novel species – trilobites. Students apply procedural skills such as using the pan balance and interpreting a graph in order to construct a model fossil record that can then be used to support further reasoning.