Question

The diagram alongside represents a layer of epidermal; cells showing a fully grown root hair.Study the diagram and answer the questions that follow:

(a) Name the parts labelled A, B, C and D.

(b) The root hair cell is in a turgid state. Name and explain the process that caused this state.

(c) Mention one distinct difference between the parts labelled A and B.

(d) Draw a diagram of the above root hair cell as it would appear when a concentrated solution of fertilizers is added near it.

Answer 1

Part (i): Structures of root hair:

1. The different parts are:​
   
2. A - Cell wall
   
3. B - Cell membrane
4. C - Cytoplasm
5. D - Nucleus
   

Part (ii): Turgid root hair:

1. A root hair gets turgid because of the absorption of water from the surrounding.
   
2. Absorption of water by root hair is achieved by the process of osmosis.
   
3. The concentration of water in the surrounding is more than that of the interior of the cell; this causes the water from the surrounding to move in because of endosmosis.

Part (iii): Difference between cell wall and membrane of root hair:

Cell wall	Cell membrane
The cell wall of a root hair is freely permeable and allows both salt and water to pass through.	The cell membrane of a root hair is semipermeable and does not allow large dissolved salt molecules to pass through

Part (iv): Root hair cell in concentrated solution: