Advertisements
Advertisements
प्रश्न
Give two examples of turgor movements in plants.
Advertisements
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.
APPEARS IN
संबंधित प्रश्न
Distinguish between the following:
Plasmolysis and deplasmolysis
Choose the correct answer:
Plasmolysis will occur when the cell is placed in a __________
Give Reasons for the following.
It is necessary to maintain a normal osmotic concentration of the blood.
Give Reasons for the following.
Salt and sugar are used in preserving food.
Differentiate between the following
Endosmosis and Exosmosis
In the figure below ‘A’ shows a cell in the normal state and ‘B’ shows the same cell after leaving it in a certain solution for a few minutes.
(i) Describe the change which has occurred in the cell as seen in B.
(ii) Give the technical term for the condition of the cell as reached in B and as it was in A.
(iii) Define the process which led to this condition.
(iv) What was the solution-isotonic, hypotonic or hypertonic, in which the cell was kept?
(v) How can the cell in B, be brought back to its original condition?
(vi) Name the parts numbered 1 to 3.
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.
Name the following:
Condition of cell in which the cell content are shrunken.
Define the following term:
Tonicity
