OBJECTIVE

Students will understand the process of seed to fork through the lens of corn. Students will explore the transformation of corn over thousands of years, and how it has become the primary crop used in the US today.

ESSENTIAL QUESTIONS

Where does corn come from? How does eating corn affect the world?

MATERIALS

Teosinte (photos or artifact)
Ear of sweet corn/dry corn (photos or artifact)
Corn seeds
Soaked corn seeds
Plant Report Worksheet
Time lapse videos: 105 days of corn, corn germination

PROCEDURE

Introduction:
Ask students: Who eats corn? What is a corn kernel? Where does it come from?
– If students have completed the “Corn Investigation,” ask for their findings.
What items did they discover contained corn? What did they find that was
surprising? What questions do they have now?
Lesson:
Invite students to dissect a soaked corn kernel. Students work in pairs to findthe
embryo, endosperm and seed coat.
As a class, discuss corn reproduction. Show time lapse videos of corn growing, and if
possible, display corn sprouts for students toobserve.
Explain the process of pollination/cross pollination. Display to students the
interaction between the tassel and silks.
Vocabulary includes: embryo, endosperm, seed coat, coleoptile, radicle, cross–
pollination, monocot
Next ask students to list all the different types of corn with which they are familiar.
Describe the corn we are using in class, and the path it took to reach the classroom.

Walk students through the process of “selective breeding,” and “domestication.”
Start with teosinte, and travel along its path to the sweet corn, popcorn, and feed
corn that we know today. Guide students through this process by asking them to
make a list of the traits they can identify in modern sweet corn (it may help to
compare sweet corn kernels to teosinte). For example:

– size of kernels
– number of kernels
– color
– shape
– height
– seed structure
– taste
Now invite students to imagine the efforts of agriculturalists over thousands of
years to transform teosinte into modern sweet corn by choosing those traits and
breeding from those seeds.
Explore the story of the particular type of corn growing in the school garden.
Ask students why they think it is important to know the path our corn seeds have
taken.

Invite students to share their knowledge of genetic modification.
– “How do you think this may change the reproduction of corn?”
– “What do you think the difference is between genetic modification and
domestication of corn?”

Extension:
If in spring: Students start corn seedlings, and transplant them into thegarden.
“What is the life cycle of this corn? What journey are we putting it on?”
If in fall: Students save corn seeds from the school garden, label the jars and safely
store them to be used in the spring.
Assessment:
Students work in groups to create signage for their corn garden bed. Theyinclude
the evolution of corn, the reproduction process of corn, and facts about where corn
comes from and where we see it today.
Students complete the Plant Report Worksheet, using corn as their crop