Question

Following are the two examples of plant movement.

(i) Which stimulus is common for movement in both the cases? 

(ii) Does the movement take place towards the point where the stimulus is received? Mention separately for both plants. 

(iii) Give one reason for the movement is each case.

Answer 1

(i) In both the cases stimulus of touch is same. 

(ii) In the mimosa plant, the movements of leaves are in the opposite direction to the touch. On touching the leaves, they curl up towards the stem. 

This is because plant cell change, their shape by changing the amount of the water in them. This happen due to swelling or shrinking of cell. 

In case of the pea, plant tendrils cling over the object or the support so the movement takes places in the direction of the stimulus. 

(iii) In mimosa plant, this movement is seen because of the change in concentration of water in the leaves. 

In pea plant, this movement is seen because of the rapid growth of that part of a tendril which is away from the stimulus or the support.