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:

(a) Name the parts indicated by guidelines 1 to 5.

(b) Is the root hair cell unicellular or multicellular?

(c) Explain what would happen to the root hair cell if some fertilizer is added to the soil close to it.

(d) Name the process responsible for the entry of water molecules from the soil into A1 and then into A2.

(e) What pressure is responsible for the movement of water in the direction indicated by arrows?

(f) How is this pressure set up?

(a) Below are the parts indicated by guidelines 1 to 5:

• 1 → Root hair cell
• 2 → Soil particles
• 3 → Xylem vessel
• 4 → Cortex cells
• 5 → Vacuole

(b) Root hair cell is unicellular.

(c) When fertilizers are added to the moist soil close to the root hair cell, it will form a hypertonic solution, resulting the protoplasm to shrink. The plasma membrane withdraws itself from the cell wall. Hence, the root hair also becomes limp or flaccid.

(d) Osmosis.

(e) Root pressure.

(f) Root pressure is built up due to cell-to-cell osmosis in the root tissue. As one turgid cell presses the next cell, the force of the flow of water increases inwards.