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प्रश्न
Give two examples of turgor movements in plants.
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उत्तर
Examples of turgor movements in plants:
- The rapid drooping of the leaves of the sensitive plant (Mimosa pudica) is an outstanding example of turgor movement.
- If one of the leaves is touched, even lightly, the leaflets fold up, and within 2 to 3 seconds, the entire leaf droops. If the leaf is touched somewhat strongly, the wave of folding and drooping spreads from the stimulated leaf to all neighbouring leaves.
- Slowly, the leaves recover and again stand erect. In this plant, the stimulus of touch leads to loss of turgor at the base of the leaflets and at the base of the petioles, called pulvinus.
- Somewhat similar turgor movements are found in insectivorous plants, whose leaves close up to entrap a living prey.
- The bending movements of certain flowers towards the sun and the sleep movements of the leaves of certain plants at night are also due to turgor movements.
संबंधित प्रश्न
Define the Cohesive and Adhesive forces.
What is the significance of diffusion?
Give Reasons for the following.
It is necessary to maintain a normal osmotic concentration of the blood.
Differentiate between:
Osmosis and Diffusion
The diagram below represents an experimental set up to demonstrate a vital process. Study the same and then answer the questions that follow:
(i) Name the process.
(ii) Define the above named process.
(iii) What would you observe in the experimental setup after an hour or so?
(iv) What control experiment can be set up for the above experiment?
(v) Keeping in mind the root hair cell and its surrounding name the part that corresponds to (1) Concentrated sugar solution, (2) Parchment paper, (3) Water in the beaker.
(vi) Name any other substance that can be used instead of parchment paper in the above experiment.
(vii) Mention two advantages of this process to the plant.
In an experiment, two sets of apparatus were set up as shown below:
In A there is a concentrated sugar solution inside the thistle funnel and red ink in the water outside the funnel. In B there is a concentrated glucose solution with red ink inside the thistle funnel and water outside the thistle funnel.
In both A and B the level of liquid inside the funnels rises up the tubes. In A the sugar solution turns red and in B, the water turns red.
Study the given observations and answer these questions:
- Name the process by which red ink moves in A and B.
- Which type of pressure forces the water molecules to move towards thistle funnels and cause a rise in the water level?
- Where does this process occur in plants and animals?
- What material could be used as a semi-permeable membrane?
Give Technical Term for the following.
The pressure which is responsible for the movement of water molecules across the cortical cells of the root.
Give Technical Term for the following.
The condition in which the water from a cell is completely removed due to exosmosis and no more shrinkage is possible.
Multiple Choice Question:
In the process of osmosis in a cell:
DPD of a cell can be expressed as ______
