Advertisements
Advertisements
Question
Why is the closing of a dandelion flower at dusk (when it gets dark) not a tropism?
Solution
The closing of a dandelion flower at dusk is not a tropism because it is a non-directional movement in response to the intensity of light. On the contrary, tropic movement is the movement of plant parts towards the light. It does not depend upon the intensity of light.
APPEARS IN
RELATED QUESTIONS
Design an experiment to demonstrate hydrotropism.
Name one example of the movement of a plant part which is very quick and can be observed easily.
What is the stimulus in geotropism?
Give the scientific terms used to represent the Growth of a pollen tube towards ovule.
Give one example of a plant part which is positively phototropic but negatively geotropic.
The climbing organs of plants like tendrils grow towards any support which they happen to touch and wind around the support. This is an example of :
(a) chemotropism
(b) nastic movement
(c) thigmotropism
(d) geotropism
Which of the following are not tropisms?
(i) growing of pollen tube in response to a sugary substance
(ii) folding up of leaves of sensitive plant in response to touch
(iii) winding of tendril around a support in response to touch
(iv) opening up of the leaves of a daisy flower in response to light
(a) (i) and (ii) (b) (ii) and (iii) (c) (i) and (iv) (d) (ii) and (iv)
Name the stimulus which causes the following movements in plants.
phototropism, thigmotropism, hydrotropism and geotropism
Write the scientific terms used to represent the following:
Growing of roots towards the gravity.
Name the stimulus which causes the following movement in plant:
Thigmotropism
