A growth movement of a plant part in response to an external stimulus in which the direction of stimulus determines the direction of response is called tropism. Thus, tropism is a directional movement of the part of a plant caused by its growth. The growth of a plant part in response to a stimulus can be towards the stimulus (in the direction of stimulus) or away from the stimulus (against the direction of stimulus) due to which we can have a positive tropism or negative tropism, respectively.
1. If the growth (or movement) of a plant part is towards the stimulus, it is called ______ tropism.
(i) Positive
(ii) Negative
2. If the growth (or movement) of a plant part is away from the stimulus, then it is called ______tropism.
(i) Positive
(ii) Negative
3. The bending of the plant stem (or shoot) towards light is actually ______ phototropism.
(i) Positive
(ii) Negative
4. State true or false. Tropism is a directional movement of the part of a plant caused by its growth.
(i) TRUE
(ii) FALSE
5. State true or false. A growth movement of a plant part in response to an external stimulus in which the direction of stimulus determines the direction of response is called tropism.
(i) TRUE
(ii) FALSE
