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प्रश्न
What does a root do in response to light? What is this phenomenon known as?
उत्तर
Root always grows downwards and away from light. This phenomenon is known as negative phototropism.
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संबंधित प्रश्न
Design an experiment to demonstrate hydrotropism.
What is the scientific name of sensitive plant?
Define geotropism.
What is meant by ‘positive geotropism’ and ‘negative geotropism’? Give one example of each type. Draw a labelled diagram to illustrate your answer, indicating the plant part, which shows positive geotropism, and the plant part, which shows negative geotropism.
A growing seedling is kept in a dark room. A burning candle is placed near it for a few days. The top part of seedling bends towards the burning candle. This is an example of :
(a) chemotropism
(b) hydrotropism
(c) phototropism
(d) geotropism
P, Q, R and S are four major types of phytohormones. P is a phytohormone which functions mainly as a growth inhibitor. It promotes the wilting and falling of leaves. Q, R and S are phytohormones which all promote growth of plants in various ways. Q is responsible for the phenomenon of phototropism in plants. R is involved mainly in shoot extensions. The phytohormone S helps in breaking the dormancy of seeds and buds. What are P, Q, R and S? Give one reason each for your choice.
When the leaves of a sensitive plant are touched with a finger, they fold up and when light fades at dusk, the petals of a dandelion flower close.
state two ways in which the above two processes differ.
Write the scientific terms used to represent the following:
Growing of roots towards the gravity.
Name the phenomenon occurring in plants which are under the control of gravity, water and chemicals with one example each that shows the movement involved.
______ of sweet peas exhibit thigmotropism.
