In this unit, students consider the phenomenon of a farmer’s crops getting destroyed by a pest.  What can farmers do to prevent this? To answer this question, students explore how different organisms use their body structures in order to sense, respond to their environment, and survive. The Crosscutting Concepts of Structure and Function, as well as Systems and System Models, are prominently featured in this unit. Students come to understand an organism as a system of structures that each have their own specific function. These structures work together in order to help the organism survive. 

To begin, students review the components of a healthy habitat, how living things use the components of a habitat, and how different organisms are adapted to live in a particular environment. 

Next, students dive deeper into the concept of adaptation, specifically thinking of adaptations in terms of external and internal structures.  They then consider what is causing behaviors to occur (external and internal stimuli), and how internal and external structures work together to help an organism respond to the stimuli in order to survive.  Students particularly focus on light, developing a model and using it to explain what happens to allow us to see so that we can respond to stimuli.  

Finally, students use what they have learned in order to apply it to their own presentation that compares animal structures across animal classes, as well as design an ideal habitat for an insect in the design challenge.  By the end of the unit, students will see that they are much more like a bug than they might have originally thought- bugs, humans, and all organisms have structures that allow them to sense and respond to their environment to survive.