Question

Movements of hairs in Drosera is

• A. Photonastic
• B. Thermonastic
• C. Thigmotropism
• D. Hydronasty

Answer 1

Answer: (C)

'Drosera' is a carnivorous sundew plant which shows the movement of organs due to change in the turgor or change in the growth called as nastic movements.

The nastic movements are nyctinastic, chemonastic and seismonastic.

In case of Drosera plant, the tentacles also bend to retain its prey and the hair/tentacles movement is faster than the leaf curling movement. The bending is accompanied by the permanent elongation of the convex side of the tentacle and the unbending by the corresponding increase in the length of the concave side. All these movements are the phenomena of growth due the mechanosensory response to the touch stimuli i.e, Seismonasty or thigmotropism. So, the correct option is 'Thigmonasty'.