Humans made new kinds of plants by mixing genes, but even the new ones still have the same poisons as the old ones.

Scientists bred broccoli to make it grow better and taste nicer, but they didn’t stop it from making its natural protective chemicals—those are still there, even if the plant’s genes became more similar.

Even when people breed plants to make them tastier or bigger, the plants still keep their natural chemicals that protect them from bugs and disease—these chemicals are still there and might even be good for us.