- Introduction of plant hormones
Shaalaa.com | Control & Co-ordination part 22 (Plant Hormones)
A big tree falls in a forest but its roots are still in contact with the soil.
The branches of this fallen tree grow straight up (vertically). This happens in response to
(a) water and light
(b) water and minerals
(c) gravity and water
(d) light and gravity
Which of the following phytohormone is not associated with the promotion of growth in plants?
(b) abscisic acid
While conducting experiments to study the effect of various stimuli on the plants, it was observed that the roots of a plant X grow and bend towards two stimuli A and B but bend away from a third stimulus C. The stem of the plant X, however, bends away from stimuli A and B but bends towards the stimulus C. The stimulus B is known to act on the roots due to too much weight of the earth. Keeping these points in mind, answer the following question :
(a) What could stimulus A be?
(b) Name the stimulus B.
(c) What could stimulus C be?
(d) The branches of a fallen tree in a forest grow straight up in response to two stimuli. What could be these two stimuli out of A, B and C? Also name these two stimuli.