Explore what students will learn and check out the additional resources that go along with the lessons. Check out our professional development opportunities to learn how to receive free training and supplies for these lessons.
One form of genetic modification that has been used for centuries is artificial selection, or selective breeding. This is the selection of individuals or populations possessing desirable traits to produce the next generation. This process has given rise to many of the plants and animals we encounter every day. An example of this is breeds of dog, where some are good at hunting and retrieving and some are bred for companionship within a home. Another example are breeds of cattle, where some are bred for milk production and others, for beef. A third example is corn, a crop that has been developed over the years and is currently being improved to produce higher yields in drought conditions, resistance to pests, and other advantageous characteristics through this process. Artificial selection also played an important role in the development of the theory of natural selection. An understanding of Mendelian inheritance and statistical analysis of the results of crosses is important in determining the genes of an organism and the ability to produce offspring with the desired traits.
In this lab, students will:
Science
Students should be cautioned to be careful when handling ears of corn. If handled with care, ears may last many years, but may be damaged if handled roughly. Kernels may occasionally fall off of the ears, but may be glued back into place.
Length of Time for Preparation: 15 minutes Length of Time for Classroom Teaching: 1 class period (45–60 minutes)
It is recommended to follow the teaching of Mendelian inheritance for this lab as students will need basic knowledge of inheritance and probability as well as the vocabulary associated with this subject and experimental procedures.
Notes for the teacher on how to introduce the topic and how to assess students for prior understanding.
Questions to pose to students after they’ve observed the cobs, without telling them if they are right or wrong.
Corn kernels can have different colors (e.g., purple or yellow) and textures (smooth or wrinkled). These traits follow Mendelian inheritance, meaning they can be dominant or recessive. Each kernel on a corn cob is a separate offspring resulting from pollination, so a single cob gives a large sample for data collection.
Analysis Questions
Hand out the student assessment sheet pages S1-S2. This assessment tool can be used to learn if learning out-comes were achieved.
Any educator electing to perform demonstrations is expected to follow NSTA Minimum Safety Practices and Regulations for Demonstrations, Experiments, and Workshops, which are available at https://static.nsta.org/pdfs/MinimumSafetyPracticesAndRegulations.pdf, as well as all school policies and rules and all state and federal laws, regulations, codes and professional standards. Educators are responsible for abiding appropriate legal standards and better professional practices under a duty of care to make laboratories and demonstrations in and out of the classroom as safe as possible. If in doubt, do not perform the demonstrations.
This lesson is the work product of the Kansas Corn Commission. Our lessons are written in collaboration with Kansas teachers for use in the classroom. Teachers may copy and share this curriculum. Use of this product for commercial or promotional use is prohibited without express permission of Kansas Corn.
As the need to produce more food with less resources grows, it is important that future generations have a better understanding of agriculture and how corn farming and agriculture fit into our daily lives. That’s why the Kansas Corn STEM program provides lessons to teach science through the lens of corn. We are committed to providing free materials and training to support educators.
