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प्रश्न
Name a plant hormone responsible for bending of a shoot of a plant when it is exposed to unidirectional light. How does is promote phototropism?
उत्तर
Auxin is the plant hormone that causes a plant's shoot to bend when it is exposed to unidirectional light. Auxin accumulates on the side of the shoot that is shaded, causing the cells on that side to elongate more than the cells on the side that is exposed to light, which causes the shoot to bend in the direction of the light source.
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संबंधित प्रश्न
How does phototropism occur in plants?
What is the stimulus in chemotropism?
Plant parts show two types of movements, one dependent on growth and other independent of growth. Give one example which does not depend on growth
Dandelion flowers open the petals in bright light during the daytime but close the petals in dark at night. This response of dandelion flowers to light is called:
The movement of a shoot towards light is:
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 tropic movement that helps the climbing vines to find a suitable support is ______.
Analogy:
Towards a stimulus: ______:: Away from the stimulus: Negative tropism.
Write the scientific terms used to represent the following:
Growing of roots towards the gravity.
Observe the three figures given below. Which of the following depicts tropic movements appropriately?
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 |
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| A | B | C |
