ANOVA of the Ethylene Glycol Germination Data

In this activity, you will be performing a one-way ANOVA on the germination data of Brassica rapa to determine if there are significant effects on germination from prolonged exposure to ethylene glycol, the main component in antifreeze. The original research was conducted by the College Biology classes at the Central Virginia Governor's School for Science and Technology. Ethylene glycol has been found to have harmful effects when ingested by both humans and animals. However, the concerns over its effects on plants have not attracted the interest in much research.

The experiment was designed with three-test groups and one control group, each group containing ten seeds. The control group used only pure water to wet the seeds whereas the experimental groups used 25%, 50%, and 100% solutions of ethylene glycol. The seeds were placed in adequately watered and lighted petri dishes that were lined with filter paper (to retain the water). Each was monitored over a 72 hour period; at the end of this time, the data was collected concerning the hypocotyl and epicotyl lengths of the plants. Using the data set in Excel, perform an ANOVA on the hypocotyl data to determine if there is a significant difference in the length of this structure among the plants grown at varying concentrations of ethylene glycol. If there is a significant difference, you will need to determine the means that are significantly different by doing a Tukey Test. Following the same procedure, complete an ANOVA on the epicotyl data as well.

 

 

 

1. Was there a significant difference in the hypocotyl or epicotyl lengths of the plants after exposure to ethylene glycol?
2. What group means were significantly different for the hypocotyl data?
3. For the epicotyl data? Were the results what you had expected from this experiment?
4. Does the ethylene glycol seem to target any particular portion of the life cycle of Brassica?


Original work on this document was done by Central Virginia Governor's School student Christian Neeley (Class of '98) and the Biology Department.


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