I've gone into my older daughter's classrooms the past two years, each time with a different slant toward corn as an interesting, fun, and important organism.
Illustration of Mendel's First Law:
Although the concept of segregation of alleles might seem too complex
for kindergartners, the kids remember aspects of the experiment a year
later. What I tried to stress here was variation in maize and how to do
an experiment. I first explained that genes control a lot of things about
us and all living things, and there are different forms of genes that basically
do the same thing but with some different effects. I illustrated this fact
by referring to eye color, and explained that my daughter Becky and I both
have blue eyes, but that Becky's sister has brown eyes like her mother.
I explained that each of us had two forms of any gene, one from our mother
and one from our father. I then told them that corn has different forms
of genes as well, and that one such gene controls plant color (I used an
albino seedling trait for this): the "green gene" (wild-type allele) makes
the plant green, and the "white gene" makes the plant white. After explaining
that the white gene is a mutant (yes, kind of like the turtles) and that
two white genes are necessary to make the plant white, I went on to tell
them that the different forms of the genes get shuffled up and some corn
seeds get two green genes, some one green and one white gene, and others
two white genes. I illustrated this by placing green and white beads into
small test tubes, and had them tell me which would give a green plant and
which could give a white plant -- most students picked up on this right
away. I then had each student come up and, with their eyes closed, pick
two beads out of a bag containing an equal number of green and white beads
and place them into a tube in a tube rack. We then separated the tubes
into green-green, green-white, and white-white classes, grouped the green-green
and green-white together since these would all give green plants, and counted
the individuals. We recorded this observation on the board (16 green:4
white), then made a prediction of what would happen if we planted 20 kernels
from an ear containing "shuffled up" green and white genes, and wrote this
on the board as a prediction. We proceeded to plant out the twenty kernels;
they promised to water the flat, and I told them I would be back at the
end of the next week to help count the plants. When we counted up the green
and white plants, we observed 13 green and 5 white plants, and I think
I convinced them that 13 is pretty close to 16 and that 5 is pretty close
to 4, without getting into ratios. The kids had a grand time at this, and
continued to talk about the experiment at home -- favorable comments were
received from several parents about this demonstration.
Corn as a Commodity:
I went into Becky's first-grade class this past fall to talk about
the importance of corn and its uses. From raiding the pantry at home I
was able to come up with a couple of shopping bags of items that contain
corn, and showed them that corn can be used for everything from trash bags
to Life-Savers. I also took in some corn-starch-based packing peanuts as
well as some styrofoam ones, and explained that corn is a renewable resource
and that we could make all of the styrofoam peanuts we want as long as
we could grow enough corn. I also showed them how the starch peanuts dissolved
in water, while the styrofoam ones did not, and asked which would be better
for the environment. Kids this age are very green-minded and they really
appreciated this demonstration. Finally, I went to the large U.S. map in
the classroom and showed them where the majority of the corn is grown in
this country (they got a kick out of the term "Corn Belt"), and told them
that the amount of corn grown this past year was equivalent to 35 Connecticuts.
Each student then came up to get his or her souvenir -- an ear of colored
corn in a pollinating bag.
I found the kids very receptive to both presentations; they asked lots of questions (particularly during the latter), and in conversations I've had with Becky's friends I can see that they remember some of the key concepts regarding corn utilization. Some of them only refer to me as "Dr. Corn".
Return to the MNL 69 On-Line Index
Return to the Maize Newsletter Index
Return to the MaizeGDB Homepage