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Question
How does phototropism occur in plants?
Solution
The growth movement in plants in response to light stimulus is known as phototropism. The shoots show positive phototropism and the roots show negative phototropism. This means that the shoots bend towards the source of light whereas the roots bend away from the light source.
For Example: The flower head of a sunflower is positively phototropic and hence it moves from east to west along with the sun.
RELATED QUESTIONS
What does a plant root do in response to water? What is this phenomenon known as?
Which of the following is a growth movement and which is not?
- Folding up of leaves of sensitive plant on touching with hand.
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A plant's response to gravity is called ______.
Plant roots grow ______ and in the direction of force of ______.
Name the plant organ which is positively hydrotropic.
What is meant by positive tropism and negative tropism? Explain with examples.
What is the difference between thigmotropism and thigmonasty? Name one plant which exhibits thigmotropism and one plant which exhibits thigmonasty. What behaviour (or responses) of these plants make you think that they exhibit thigmotropism and thigmonasty respectively?
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(a) hydrocarbon
(b) hydrogen oxide
(c) hydrogen chloride
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The bending of root of a plant in response to water is called ______.
The root of the plant is ______.
- positively phototropic but negatively geotropic
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The growth of pollen tubes towards ovules is due to
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Write the scientific terms used to represent the following:
Bending of roots towards the water.
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 |
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?
Study the diagrams given below and answer the following questions:
- Name the structures shown as X and Y in the figures (A) and (B), respectively.
- Write the functions performed by the structures X and Y.
- Name the phenomenon depicted and define it.
- How do the structures X and Y differ from each other?
- Give examples of the plants which show the said phenomenon.
