Experimental Design and Statistical Analysis:
Bt Corn, Lignin, and ANOVAs

Part III—"Results—Figures"

by
Eric Ribbens
Department of Biological Sciences
Western Illinois University

The six graphs below show the mean lignin content for the six isolines of corn for which data was reported for both field and growth room trials for both Bt and non-Bt varieties.  The red line represents the field trials and the blue line represents the growth room trials.  The Bt-modified corn is on the left, and the non-modified corn is on the right.  Lines are included for purposes of enabling greater visual clarity of the differences and interactions, and do not imply that intermediate values could exist.  These graphs were constructed from the data provided in the paper in Tables 1 and 2.

DK626N67-T4
N7590NC4990
Nk4640P31B13

Questions:

10.  Why did they test multiple varieties of corn?
11.  a.  Based on the six graphs, what do you conclude about differences in the percent lignin content between the growth room and the field?  Between Bt corn and non-Bt corn?  Between the six varieties of corn?  Is it appropriate to make generalizations, or is there evidence that generalizations cannot be supported by the data?
11.  b.  Based on the bar graph below what do you conclude about differences in the percent lignin content between the growth room and the field?  Between Bt-corn and non-Bt-corn?  Between the six varieties of corn?  Is it appropriate to make generalizations, or is there evidence that generalizations cannot be supported by the data?
% light graph


Go to Part IV—"Results—Tables"



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