NOTES TO FACULTY

The four figures are from experiments concerning possible impacts of Bt corn pollen on monarch butterflies. In Figure 2C, make sure students understand that Cry1Ab, Cry1Ac, Cry9C, and Cry1F are the Bt genes which produce proteins which may be toxins. Bt11, Mon810, Dbt418, Cbh351, and Tc1507 are the hybrids that contain these toxins.

Make sure to discuss the problems and benefits of laboratory experiments versus field experiments. Critics of the original 1999 study have indicated that the toxins in transgenic corn’s pollen might become inactive more quickly in the field than in the laboratory. Another interesting discussion would be the bases for the various experimental designs - the specific questions the scientists were asking.

Student Assessment:

After their pairs-check, each four-person group will prepare a short (5-10 minute oral presentation to the class. The groups will use the four figures (one, some, or all) and base their presentations on whether or not the use of the Bt corn should be banned.

An effective way to help students give more effective oral presentations is by giving them a rubric ahead of time detailing how you will judge the quality of their talks. Spend time in class discussing the rubric as well. For an explanation and an example of such a rubric see: www.siue.edu/~deder/assess/cats/grrubi.html and www.rickhershberger.com/bioactivesite/bio103/symposium/rubric.pdf.