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प्रश्न
With the help of an experiment, prove that roots are more positively hydrotropic than geotropic.
उत्तर
Aim:
To prove that roots are more positively hydrotropic than geotropic.
Apparatus:
Wire netting or gauze, wires, moist sawdust, germinating bean seeds
Procedure:
Take a piece of wire netting or gauze and suspend it with the help of wires.
Place moist sawdust of about 1 inch on the wire netting.
Embed some germinating bean seeds in the sawdust.
Observation:
As the seeds germinate, the radicles initially grow downwards through the wire netting under the influence of gravity. However, after some time they start growing upwards towards the moist sawdust. The shoots grow upwards all the time.
Inference:
Roots grow in the direction of gravity and water. The growth of roots towards water and overcoming the force of gravity suggests that roots are positively hydrotropic than geotropic. This implies that water is a more effective stimulus than gravity.
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संबंधित प्रश्न
What is meant by nastic movements in plants? Give one example of nastic movements in plants.
Plant roots grow downward in response to ______.
Why is the closing of a dandelion flower at dusk (when it gets dark) not a tropism?
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:
- What could stimulus A be?
- Name the stimulus B.
- What could stimulus C be?
- 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.
The venus flytrap plants are examples of ______.
______ flowers bloom as the temperature increases.
Analogy:
Towards a stimulus: ______:: Away from the stimulus: Negative tropism.
______ of sweet peas exhibit thigmotropism.
Name the stimulus which causes the following movement in plant:
Hydrotropism
Name the stimulus which causes the following movement in plant:
Geotropism