Question

Choose the correct answer from each of the four options given below:

Thigmotropism is best seen in

• A. Tendrils
• B. Stem apex
• C. Leaves of sensitive plant
• D. Root apex

Answer 1

The correct option is A

Tendrils

The correct option is option A.

Explanation for the correct option:

Thigmotropism:

1. It is a directional growth movement of curvature which occurs in response to the stimulus of contact.
2. Thigmotropism is found in twiners and tendrils.
3. After initial contact with support due to mutation, the tendril or twiner shows less growth in the region of contact and more growth on the other side.
4. As a result, it bends over and encircles the support.

Explanation for the incorrect options:

Option B:

Stem apex show phototropism or directional growth towards light exposure.

Option C:

Leaves of sensitive plants show thigmonasty which is a movement that is not dependent on the direction of the stimuli.

Option D:

The root apex shows hydrotropism which is the directional movement towards the water.

Final Answer: Thigmotropism is best seen in Tendrils.