Hybrids, especially fertile hybrids, occur much more readily in plants than in animals. An example of a commonly used hybrid plant is wheat, which contains the genes of three closely-related plants. A gene, whose presence is easily detectable, which is inserted into a GMO along with the desired gene. The presence of the marker gene allows scientists to know that the insertion of the genes has been successful. A chemical designed to kill a particular pest.
Some pesticides are more selective than others.
A type of molecule occurring in all living things. There is a huge variation in protein size and function depending on how the units are put together. The instructions for how to assemble proteins are usually contained within DNA molecules. Even within one species, interbreeding may not always occur because of natural barriers. Among some plants and many micro-organisms, the concept of a species does not always work.