Advertisements
Advertisements
प्रश्न
Which of the following acts as a stimulus in the process of hydrotropism?
(a) hydrocarbon
(b) hydrogen oxide
(c) hydrogen chloride
(d) hydrogen peroxide
उत्तर
(b) Hydrogen oxide
Water or hydrogen oxide acts as a stimulus in the process of hydrotropism.
APPEARS IN
संबंधित प्रश्न
What is the stimulus in phototropism?
What does a tendril do in response to the touch of a support? 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.
- Folding up of petals of dandelion flower when light fades.
Plant roots grow ______ and in the direction of force of ______.
What is meant by positive tropism and negative tropism? Explain with examples.
The growth of tendrils in pea plants is due to the :
(a) effect of sunlight on the tendril cells facing the sun
(b) effect of gravity on the part of tendril hanging down towards the earth
(c) rapid cell division and elongation in tendril cells that are away from the support
(d) rapid cell division and elongation in tendril cells in contact with the support
Which of the following are not tropisms?
(i) growing of pollen tube in response to a sugary substance
(ii) folding up of leaves of sensitive plant in response to touch
(iii) winding of tendril around a support in response to touch
(iv) opening up of the leaves of a daisy flower in response to light
(a) (i) and (ii) (b) (ii) and (iii) (c) (i) and (iv) (d) (ii) and (iv)
State whether true or false. If false, correct the statement.
The response of a part of plant to the chemical stimulus is called phototropism.
Assertion (A): If the plant part moves in the direction of gravity, it is called positive geotropism.
Reason (R): Stem shows positive geotropism.
The figure given below depicts a kind of tropic movement in plants. Study the same and answer the following questions:
- What kind of a movement is shown in the figure? Define it.
- How does this movement differ from geotropism?
- Name the stimulus responsible for thigmotropism. Give one example of a plant showing thigmotropism.
- Name one stimulus which gives a positive response for the roots but a negative response for the shoot.
- Draw a neat and labelled diagram of the part of a plant showing leaf tendril. Name the plant.
