7.4 What Can Cause Populations to Change?
This module is a project-based module that builds on students’ earlier explanation of natural resources—the water, atmosphere, and land around us. In this module, they continue investigating the biosphere, building understanding of how organisms depend on each other as well as how they can be affected by events that disrupt ecosystem function. This module focuses on organisms’ needs for survival, what happens when those needs are not met, and how humans can act to mitigate changes. Over the course of the module, students will learn more about why food is important (building on what they learned about the body in 6th grade and about food at the molecular level in the previous module), investigate why different structures are needed and how they are used by organisms to eat and reproduce, and investigate relationships between organisms (e.g., predator/prey, producer/consumer, parasite/ host, and competition). As they work to solve a mystery in which they investigate an invasive species, students will also investigate abiotic factors that affect ecosystems. The module concludes with two engineering-themed activities in which students explore ways that humans can participate in solving ecosystem problems. Students engage in a group or independent research project in which they apply everything they have learned either to problems caused by a local invasive species or to another local environmental problem, and consider how it might be solved. The research project lays the groundwork for more extensive research on human/ Earth interaction and interrelatedness to be done in 8th grade.