Question

The accurate relationship between SP, OP, and TP can be expressed as:
A. SP=OP+TP
B. OP=SP-TP
C. TP=SP-OP
D. SP=OP-TP

Answer 1

Hint: The full form of SP, OP, and TP are suction pressure, osmotic pressure, and turgor presser respectively.
The difference between the diffusion pressure of pure water and a solution is called diffusion pressure deficit or DPD, which is also similar to SP.

Complete answer: OP or osmotic pressure can be defined as a pressure that is applied to pure water solvent to avoid it from passing into a given solution by the process named osmosis. This term is used to define the concentration of a solution.
The osmotic pressure is responsible for the gain of the pressure of water and turgor pressure is the opposing pressure of the osmotic pressure.
TP or turgor pressure can be defined as a force inside the cell that helps to push the plasma membrane against the cell wall. It is also called hydrostatic pressure.
Suction pressure or SP is the difference between OP and TP.
SP = OP – TP

Thus, the correct answer is option D. SP = OP – TP

Note: In a fully turgid cell, turgor pressure is equal to osmotic pressure.
So, here the SP is zero.
Again, in a flaccid cell, the TP has decreased thus the value becomes negative and the SP becomes almost equal to the OP or osmotic pressure.