Question

(a)What is meant by ‘tropisms’ (or tropic movements)? Explain with an example.

Answer 1

•The growth of the plant’s part in response to an external stimulus, where the direction of growth is determined by the direction of the stimulus, is defined as tropism.
•Depending upon the direction of response to the stimulus received, the tropism is said to be showing positive and negative tropism.
•For example, the roots of a plant grow towards gravity and hence are called positive geotropic whereas, the plant’s shoot grows against gravity and hence is called negatively geotropic.