Question

Plants do not have any nervous system but yet, if we touch a sensitive plant, some observable changes take place in its leaves. Explain how could this plant respond to the external stimuli and how it is communicated.

Answer 1

Plants do not have a nervous system like animals but are known to respond to a number of external stimuli with the help of receptors and hormones. The receptors help the plants to sense the external stimulus and act accordingly. As a result of these stimuli, various growth hormones are produced which result in the movement or directed growth of the plant. A similar response is observed when the leaves of Touch-me-not plants are touched. They show seismonastic movement due to the presence of receptors for touch stimulus.