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Question
The bending of the root of a plant away from a source of light is caused by a plant hormone called :
(a) cytokinin
(b) gibberellin
(c) abscisic acid
(d) auxin
Solution
(d) auxin
The plant hormone auxin is responsible for negative phototropism in roots.
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While conducting experiments to study the effects of various stimuli on the plants, it was observed that the roots of 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 stimulus A and B but bends towards the stimulus C. The stimulus B is known to act on the roots due to factors related to Earth. Keeping these points in mind, answer the following questions:
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