I have taken college courses which taught the basics creating genetically modified organisms. There is still unknown effects at the genetic level. There are changes in the physiology we may not be able to understand or detect. Breeding programs can be used to enhance disease resistance.
There are examples of genetically modified organisms genes contaminating other crops as well as native plants and changing the ecosystem.
There are examples of genetically modified organisms genes contaminating other crops as well as native plants and changing the ecosystem.