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प्रश्न
The root of a plant grows downward. This is known as ______.
उत्तर
The root of a plant grows downward. This is known as geotropism.
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संबंधित प्रश्न
What happens to the dandelion flower
- during the daytime, and
- at night?
What is this phenomenon known as?
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?
The chemical substance P is made and secreted by the meristematic tissue at the tip of stem (or shoot) of a plant. The chemical substance P is responsible for a phenomenon Q in plants in which the stem bends towards a source of light. The same chemical substance P has an opposite effect on the root of a plant. It causes the root of a plant to bend away from the source of light in a process called R.
(a) What is the chemical substance P?
(b) State whether P prefers to remains in the sunlit side of a stem or in shade.
(c) What is the effect of substance P on the rate of growth of (i) a root, and (ii) a stem?
(d) What is the name of process (i) Q, and (ii) R?
(e) What is the general name of chemical substances like P? Name another substance which belongs to this class of chemical substances.
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.
Higher Order Thinking Skill.
There are 3 plants A, B and C. The flowers of A open their petals in bright light during the day but closes when it gets dark at night. On the other hand, the flowers of plant B open their petals at night but closes during the day when there is bright light. The leaves of plant C fold up and droop when touched with fingers or any other solid object.
- Name the phenomenon shown by the flowers of plant A and B.
- Name one plant each which behaves like the flowers of plant A and B.
- Name the phenomenon exhibited by the leaves of plant C.
- Name the plant which behaves like the leaves of plant 'C'?
The movement of sunflower in accordance with the path of sun is due to
Write the scientific terms used to represent the following:
Bending of roots towards the water.
Some plants like pea plants have tendrils which help them to climb up other plants. Explain how is it done. Name the plant hormone responsible for this movement.
Where are auxins synthesized in a plant? Which organ of the plant shows:
- Positive phototropism
- Negative geotropism
- Positive hydrotropism
Name the stimulus which causes the following movement in plant:
phototropism
