Endocrine Glands - The Producers Of Chemical Messengers

  • Question
    ICSEENIBI10003526

    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.

    Solution

    i.
    1 - Root hair
    2. Soil particles
    3. Xylem
    4. Cortex
    ii. Osmosis is the process which enables the passage of water from the soil into the root hair. 

    iii. The pressure responsible for the movement of water is "Root Pressure".
     Root Pressure - It is the pressure developed in the roots due to the movement of water from the soil into the living cells of the root by cell to cell osmosis into the xylem vessels by which ascent of sap occurs in the stem.

    iv. The phenomenon is known as Guttation.
    v. 

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