Q86 / 200 · MHT CET - Medical 2026 (25 April Shift 2) · Biology

Which of the following statements are correct about absorption of water in plants?
A. When water is absorbed by root hair cell its turgor pressure increases.
B. Its D.P.D. decreases.
C. The cortical cells immediately next to epiblema has more D. P. D.
D. A gradient of suction pressure develops from cells of the epiblema to the pericycle of the roots.
E. In roots, metaxylem is in close proximity with pericycle.
Choose the correct option given below.

  • Correct answer
    A
    A, B, C and D only
  • B
    A, B, C and E only
  • C
    B, C, D and E only.
  • D
    A, C, D and E only

Solution

When water is absorbed by a root hair cell, its turgor pressure (TP) increases due to the entry of water.

Diffusion Pressure Deficit (DPD) is given by DPD = OP - TP. As TP increases, the DPD of the cell decreases.

Water moves from a region of lower DPD to a region of higher DPD. For water to move from the root hair (epiblema) to the adjacent cortical cells, the cortical cells must have a higher DPD.

A continuous gradient of suction pressure (which is equivalent to DPD) is established from the epiblema to the pericycle, facilitating the inward radial movement of water.

In roots, the xylem is exarch, meaning the protoxylem lies towards the periphery and the metaxylem lies towards the center. Thus, the protoxylem is in close proximity to the pericycle, not the metaxylem. Statement E is incorrect.

Therefore, statements A, B, C, and D are correct.

Answer: A, B, C and D only

Hence, the correct answer is option: 'A'.

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