Question

The mathematical expression of diffusion pressure deficit is

Answer 1

Hint:

• The suction pressure is also termed as diffusion pressure deficit or DPD which is defined as the difference between the diffusion pressure of the solution and its solvents at particular atmospheric conditions.

Complete answer:

• When a plant cell is placed in a hypotonic solution, the water of the solution gets inside into a cell through the process of osmosis which causes an increase of turgor pressure in the cell which is in solution. As a result of this, the cell membrane gets stretched and the osmotic pressure of the cell becomes reduced.

• When a cell is fully inflated, its osmotic pressure becomes equals to turgor pressure, and the diffusion pressure deficit becomes zero. In a plant cell, the diffusion pressure deficit can be meant as the actual thirst of a cell for water and that is expressed as DPD = OP - TP.

• At a time When DPD becomes zero, the water cannot enter the cell. Thus, it is the value of DPD that represents DPD is observed to be equal suction pressure.

Now let us find solution from given options:

• T.P : it is defined as Turgor pressure. It is defined as the pressure developed due to the occurrence of stretch in walls of plants. DPD = OP - TP.

• О.Р : it is defined as osmotic pressure. It is defined as pressure developed due to movement of water from high water to low water concentration. DPD = OP - TP.

• D.P : it is defined as diffusion pressure. The diffusion pressure deficit is defined as the amount by which two solutions varies in diffusion pressure.

• W.P : it is termed as water potential.

Hence, the correct answer is option (C)

Note:

• The term diffusion pressure deficit or DPD was first prescribed and coined by B.S Meyer in 1938. It was defined as suction pressure by Renner in 1915. He defined DPD as a reduction in the diffusion pressure of water in solution or cell over its pure state due to the presence of solutes in it and forces opposing diffusion.