Phototropism is the growth of an organism which responds to a light stimulus. It is most often observed in plants, but can also occur in other organisms such as fungi. The cells on the plant that are farthest from the light have a chemical calledauxin that reacts when phototropism occurs.
In plants, the response to a stimulus is known as a tropism. This plant movement toward or away from a stimulus can come in many forms. Before we look at a few, let's better understand the word tropism.
