Question

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:

Name the parts indicated by the guidelines 1 to 4.
Which is the process that enables the passage of water from the soil into the root hair?
Name the pressure that is responsible for the movement of water in the direction indicated by the arrows. Define it.
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?
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.

Accepted Answer

Answer

i. 1. Root hair cell

2. Soil particles / soil water

3. xylem vessel

4. Cortex cells

ii. Endosmosis

iii. Osmotic pressure / Root Pressure

– It is the minimum pressure to be exerted to prevent the passage of pure solvent into the solution when the two are separated by a semipermeable membrane
– It is the pressure caused due to cell to cell osmosis.

iv. guttation/ exudation

v.

diagram:- shrunken protoplasm, flaccid root hair