Answer
While this is possible, it is unlikely since any toxicity or problematic loss would likely help to select against such plants, eliminating them from the population. Further, GM foods can be tested on animal models if toxicity or nutrient-deficiency is a concern for consumers.
Work Step by Step
This question is asking you to imagine ways in which potential issues with food safety due to the use of GMOs could be eliminated by basic biological principles (skim the book, especially with regard to evolution and natural selection) and for ways to test for problems and, thus, to avoid them.