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Question
Concentration of mineral nutrient elements is higher inside the root hairs than in the surrounding soil. How do roots take them in from the soil?
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Solution
If the concentration of mineral nutrient elements is higher inside the root-hairs than in the
surrounding soil, then roots take them in from the soil by 'active transport'. In active transport, the mineral ions are forcibly carried from the surrounding soil i.e. the region of their lower concentration into the roots i.e. the region of their higher concentration through the cell membrane by expenditure of energy. This energy is supplied by the cell in the form of ATP.
RELATED QUESTIONS
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.
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 |
Differentiate between the following:
Guttation and bleeding
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.
Name the following:
Water is absorbed from the soil by which part.
Give Technical Term for the following.
The tissue responsible for the ascent of sap in plants.
Describe structure of root hair.
Identify the part of the plants which is responsible for maximum absorption of water.
Roots of the plants absorb water from the soil through the process of ____________.
Root hair is a cytoplasmic extension of ______.
