Materials | Multiple ears of corn (preferably of three different varieties), science notebooks or copies of the handout, computers with Internet access and a projector.
Overview | Where did corn, or maize, originate, and how did its cultivation contribute to civilization? Why do botanists and agronomists continue to study and selectively breed corn today? How is variation important in this process? In this lesson, students use prior knowledge to tout corn in a 30-second commercial spot. Then, using observation skills, they investigate variations in different types of corn and develop an understanding of the role natural variation plays in its selective breeding. Finally, they apply their learning to explain how artificial selection works and to execute a concluding project.
Warm-up | At the beginning of class, give each group of students an ear of corn (in the husk), and issue the following challenge:
You have 10 minutes to create a 30-second commercial spot about corn, to be performed as a skit for the class. To get started, think about these questions:
What associations do you have with corn? What do you want to tell a TV audience about corn?
Your group might promote corn as a food source, as the“Got Milk?” and “The Other White Meat” campaigns did for milk and pork, respectively. You might choose to focus on a corn-related topic in the news recently, such as high-fructose corn syrup, genetically engineered corn or the production of corn ethanol. Or you might simply demonstrate the uses of corn or your experiences with it, such as stories about eating corn on the cob at a summer picnic, getting lost in a corn maze, seeing rows of corn growing in a field, eating corn tortillas or even visiting theCorn Palace in South Dakota.
