A friend of mine, who shares some of the same obsessions I do for keeping crud out of our children's bodies, posted an article on Facebook showing a quick and easy way to differentiate between organic, conventionally grown, and genetically modified foods.
I took the information I learned from the article to the store with me and through my own refrigerator. It was interesting to see with my own eyes what was what, and easy to seek out which were modified from the fruits and vegetables that were labeled with those little stickers that I've always found annoying (probably because I was accused by the head chef of the first restaurant I worked in for julienning a few pounds of bell peppers without first removing the stickers which left little shreds of paper all through the finished product even though it was done by a coworker. Like I would be so dumb...grr! Said coworker was not called in to work again after being caught eating a NY steak from the walk-in.).
I was happy to see that the produce in my fridge was organic or conventionally grown (i.e. pesticide ridden). I try to buy as much organic as I can, but some things, like berries, I can't find in the store organically grown, others are not labeled, some, like oranges, are just way too expensive.
Even in the produce section of the store, I wasn't able to find anything genetically modified. This doesn't mean they weren't there. I don't know if they are required to be labeled as such, but I feel more confident with this knowledge behind me.
Basically, organic produce is numbered with a 9 at the beginning of the sequence, conventionally grown food has a number 4 printed first, and genetically modified produce begins with a number 8.
Try using this easy guide to keep track of naturally grown food if you are concerned about such things.