What do people do to plants to make them genetically modified?

As Jossi was just outlining there, one of the ways to do this is to resort to biotechnology. In other words, you can use techniques which are standard laboratory techniques to do this. One of the things you can do is use a bacterium. It's called agrobacterium tumefaciens and is a natural soil bacterium that has naturally evolved a way to genetically modify plants. The way it does that is it has an element called a transposon. These transposons are little pieces of DNA that can insert themselves into the genetic material of a plant. So what you do is to insert into that transposon the genes that you want to transfer into a plant. You then disarm the bacterium so that it's unable to do what it normally does, and you use that technique to move the gene you want into the plant's DNA. The reason a bacterium usually does this is because it wants to encourage an area of growth, or a gall, in the root or stem of the plant, which is an ideal home for that bacterium. So you're using what nature has already provided and subverting it into producing another kind of plant for you with some additional techniques and characteristics. This can mean a bigger crop, but you can also add genes that give the plant pesticide resistance or resistance to certain types of insect pest.