Gibberellins are hormones that increase the size of plants, mainly in the stems and fruits. Gibberellins can be used to produce seedless fruits (along with auxins) and are responsible for rapid early growth in many plants. Some plants are harmed when exposed to gibberellins because the stems grow too tall and are too weak to support the plant.

The picture shows five maize (corn) plants. The one on the left is a normal maize plant and the other 4 are dwarfs made by the researchers. How do you think the researchers made these dwarfs?