Diff between phototropisim chemotropisim

Dear Student

Types of tropisms


The growth movement in plants in response to light stimulus is known as phototropism. For example, the flower head of a sunflower is positively phototropic as it moves from East to West, along with the movement of the Sun.

In the above activity, the shoots show positive phototropism while the roots show negative phototropism.

The ovary stalk of groundnut is positively phototropic before fertilization and becomes negatively phototropic after fertilization. This is the reason why fruits such as groundnuts are formed underground.


The growth movement in plants in response to chemical stimuli is known as chemotropism. For example, the growth of pollen tube towards the ovule in the ovary (through the stigma and style) is an example of positive chemotropism.


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