Which plants contain cucurbitacins?
Katrina Lustofin
(lustofin@uiuc.edu)
(ready to use)
ASK
Partner Projects
| GK-12 Teaching Fellowships |
Subject Areas
Grade Levels
Unit Keywords
|
chromatography, cucumber beetles, chemistry, entomology, biology |
Rationale of the Unit
| This lab utilizes a unique way to visualize chromatography, by having cucumber beetles feed on the spots on the plate. |
Background and Resources
We used field caught cucumber beetles (the earlier in the season you can get them, the better, as their attraction to cucurbitacins diminishes in the fall).
We also used a variety of Cucurbitaceous plants: squash, pumpkin, gourds. We provided the students with a variety of plant tissues, including blossoms, fruits, seeds, and leaves.
|
Activities and Open-ended problems
Dialogues, Discussions, and Presentations
After the lab, we had a discussion with the students on how plants defend themselves and how what tastes horrible to us (cucurbitacins are very bitter) might be attractive to a beetle.
Since our beetles were too old, they were not very attracted to the cucurbitacin spots. As a back-up we examined the plates under UV and then discussed how an organisms priorities might change as the seasons change (our beetles were very interested in mating, but not in feeding). |
Assessment, Related Questions, and Story of the Unit
| Since none of the beetles actually fed in our experiment, it was a great opportunity to discuss with the students the idea that often in science, you do not get exactly the results that you anticipated. We discussed ideas of why the results were not as expected and what could be done to make the experiment work differently. |
Credits & Acknowledgements
| Susan Camasta's chemistry class, GK12 program |
Uploaded Files:
CucurbitacinBioassay.doc
If you want to add your comments on this Unit, please login first.
|
