Question

The figure given 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:

1. Name the parts indicated by the guidelines 1 to 4.
2. Which is the process that enables the passage of water from the soil into the root hair?
3. Name the pressure that is responsible for the movement of water in the direction indicated by the arrows. Define it.
4. 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?
5. Draw a well-labelled diagram of the root-hair cell as it would appear if excess of fertiliser is added to the soil close to it.

Answer 1

1. 1. Root hair
   2. Soil water
   3. Xylem vessels
   4. Cortical cells
2. Osmosis enables the passage of water from the soil into the root hair.
3. Osmotic pressure: Osmotic pressure is defined as the pressure needed to prevent the entry of pure water into an aqueous Solution through a semi-permeable membrane, thereby preventing an increase in the volume of the solution.
4. Guttation
5.