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प्रश्न
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उत्तर
Root Pressure is the pressure exerted on the liquid contents of the cortical cells of the root, under fully turgid condition, forcing a quantity of water into the xylem vessels and through them upwards into the stem up to a certain height.
Demonstration of Root pressure:
(a) Take a well matured healthy herbaceous plant.
(b) The stem of the plant is cut a few centimeters above the base with a sharp knife and attached to a manometer through a rubber tube.
(c) After a few hours, the level of mercury rises in the manometer.
(d) This is due to the pressure created by water exuded from the cut end of the plant on account of root pressure generated due to entry of water in the root cells.
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संबंधित प्रश्न
The diagram of an given below demonstrates a particular process in plants. Study the same and answer the questions that follow :
(i) Name the apparatus.
(ii) Which phenomenon is demonstrated by this apparatus?
(iii) Explain the phenomenon mentioned in (ii) above.
(iv) State two limitations of using this apparatus.
(v) What is the importance of the air bubble in the experiment?
(vi) Name the structures in a plant through which the above process takes place.
Match the items in column I with those in column II
| Column I | Column II | ||
| (a) | Xylem | (i) | semi - permeable |
| (b) | Phloem | (ii) | permeable |
| (c) | Cell membrane | (iii) | downward flow of sap |
| (d) | Root pressure | (iv) | upward flow of water |
| (e) | Cell wall | (v) | guttation |
The diagram given below represents a plant cell after being placed in a strong sugar solution. Guidelines 1 to 5 indicate the following:
1. Strong sugar solution
2. Cell wall
3. Protoplasm
4. Large vacuole
5. Nucleus
Study the diagram and answer the questions that follow:
(i) What is the state of the cell shown in the diagram?
(ii) Name the structure which acts as a selectively permeable membrane.
(iii) If the cell had been placed in distilled water instead of strong sugar solution which feature would not have been present?
(iv) If the cell in the diagram possessed chloroplasts where would these be present?
(v) Name any one feature of this plant cell which is not present in animal cells.
Choose the correct answer:
Meaning of ascent of sap is ____________
Mention whether the following statement is true (T) or false (F) and give explanation in support of your answer.
Dry seeds when submerged in water swell up due to endosmosis.
A thin strip of epidermal cells from the fleshy scales of an onion bulb was examined in a drop of water, under a microscope. All the epidermal cells looked alike and the figure alongside represents one of them. The thin strip was then transferred to a drop of strong sugar solution and re-examined under the microscope after about five minutes.
(i) Make a sketch of one of the epidermal cells, as it might appear after immersion in a strong sugar solution. Label any two parts which have undergone a change.
(ii) Give the scientific term for the change shown in Q.(i) above.
(iii) What would you do to bring this cell back to its original condition?
(iv) Give the scientific term used for the recovery of the cell as a result of the step taken in Q.(iii) above.
Name the following:
Root hairs are the extension of which cells.
Give Technical Term for the following.
The tissue responsible for the ascent of sap in plants.
________ type of tissues are present in epiphytic roots.
Identify the part of the plants which is responsible for maximum absorption of water.
