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प्रश्न
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.
APPEARS IN
संबंधित प्रश्न
The figure given below is a diagrammatic representation of a part of the cross section of the root in the root hair zone. Study the same and then answer the questions that follow
(i) Name the parts indicated by the guidelines 1 to 4.
(ii) Which is the process that enables the passage of water from the soil into the root hair?
(iii) Name the pressure that is responsible for the movement of water in the direction indicated by the arrows. Define it.
(iv) Due to an excess of this pressure sometimes drops of water are found along the leaf margins of some plants especially in the early mornings. What is the phenomenon called?
(v) Draw a well labelled diagram of the root hair cell as it would appear if an excess of fertiliser is added to the soil close to it.
State whether the following statement is true or false. Rewrite the false statement correctly.
Water absorption mainly occurs through the root-hair.
Draw a magnified view of the root-hair, and describe, how it helps in the absorption of water from the soil.
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 figure shows a diagrammatic representation of the movement of certain substances inside the stem of a certain plant. Write five sentences on whatever you can explain about the processes or the arrangement of structures indicated in the diagram.
Note: - Each sentence must include one or more of the following four words, and each word can be used several times. Xylem, phloem, roots, leaves.
Multiple Choice Question:
Process of endosmosis stops:
Which part of the root helps in maximum absorption of water and minerals?
____________plants like orchids absorb water vapours from air with the help of epiphytic roots having special tissue called velamen.
Which plant does tissue transport water and minerals from the roots to the leaf?
Water in the root enters due to ______.
