10th Class Science Control and Coordination Tropic Movement

         Tropic Movement

The movement of organism towards or away from the stimulus is called tropic movement. If the movement is towards the stimulus then it is called positive stimulus and if it is away from the stimulus then it is called negative stimulus. The various types of tropic movements are:

              Phototropism

The response of organism towards the light is called phototropism. For example, a money plant kept in a pot in a room grows more towards the direction from which the light is coming, as compared to the other direction.

              Geotropism

Response of organism towards the gravity is called geotropism. The root of the plant grows deep into the earth is an example of geotropism.

             Hydrotropism

The growth of plants parts towards the water is called hydrotropism.

              Chemotropism

The growth of plant parts towards the chemicals is called chemotropism. For example roots, of plants grows more towards the chemical fertilizers.

           Thigmotropism

The response of organism towards the touch or contacts is called thigmotropism. For example, touch me not plant.