There are some plants called 'climbing plants' which have weak stems and hence cannot stand upright )or erect. on their own. The climbing plants have climbing organs called tendrils. Tendrils are the thin, thread-like growths on the stems or leaves of climbing plants. Thus, there are two types of tendrils : stem tendrils and leaf tendrils. Tendrils are sensitive to the touch (or contact) of other objects. That is, tendrils have cells which can sense their contact with a nearby solid object like a bamboo stick, or the stem of another plant. So, when a tendril touches an object, then the side of tendril in contact with the object grows slowly than its other side. This causes the tendril to bend towards the object by growing towards it, wind around the object and cling to it. The winding movement of the tendril of a climbing plant is an example of thigmotropism. The stimulus in thigmotropism is the touch (or contact) of an object. The winding movement of the tendril of a plant around a nearby object gives support to the plant having a weak stem.
1. State true or false. Tendrils are the thin, thread-like growths on the stems or leaves of climbing plants.
(i) TRUE
(ii) FALSE
2. State true or false. Tendrils are sensitive to the touch (or contact) of other objects.
(i) TRUE
(ii) FALSE
3. The winding movement of the tendril of a climbing plant is an example of?
(i) Geotropism
(ii) Thigmotropism
(iii) Phototropism
4. State true or false. Tendrils are positively thigmotropic which means that they grow towards things they happen to touch.
(i) TRUE
(ii) FALSE
5. Tendrils are the climbing organs of the plants which are ________ thigmotropic.
(i) Negatively
(ii) Positively
