O.P.,T.P., I.P., D.P.D Questions in English

(A) Active absorption occurs due to the metabolic activity of the root cells,specifically the root hairs.
$A$ root hair cell functions as an osmotic system where water is absorbed from the soil into the cell sap due to the osmotic gradient.
Therefore,the process is primarily affected by the osmotic concentration of the cell sap relative to the soil solution.

(C) The movement of water from one cell to another is determined by the $Diffusion \ Pressure \ Deficit$ $(DPD)$.
$DPD$ is the difference between the diffusion pressure of a pure solvent and the diffusion pressure of the solution.
Water always moves from a region of lower $DPD$ to a region of higher $DPD$ (or from a region of higher water potential to a region of lower water potential).
Therefore,$DPD$ is the primary parameter that governs the direction of water flow between cells.

(A) The $DPD$ (Diffusion Pressure Deficit) or $SP$ (Suction Pressure) of a cell is calculated as $DPD = OP - TP$.
For cell $A$: $DPD = 5 - 4 = 1 \text{ atm}$.
For the surrounding cells: $DPD = 3 - 1 = 2 \text{ atm}$.
Water always moves from a region of lower $DPD$ to a region of higher $DPD$.
Since the $DPD$ of cell $A$ $(1 \text{ atm})$ is lower than the $DPD$ of the surrounding cells $(2 \text{ atm})$,water will move from cell $A$ to the surrounding cells.

(C) $DPD$ (Diffusion Pressure Deficit) is defined as the difference between the osmotic pressure $(OP)$ and the turgor pressure $(TP)$ of a cell.
Mathematically,it is expressed as: $DPD = OP - TP$.
$OP$ is the pressure exerted by solutes in a solution,while $TP$ is the pressure exerted by the cell contents against the cell wall.

(A) The actual pressure with which water enters into a cell is known as the Diffusion Pressure Deficit $(DPD)$.
$DPD$ is the difference between the diffusion pressure of pure water and the diffusion pressure of the solution.
It represents the water-absorbing capacity of a cell.
As $DPD$ increases,the water-absorbing capacity of the cell also increases.

(C) In a fully turgid cell,the water potential is in equilibrium with the surroundings,meaning no net water enters the cell.
The relationship between these pressures is given by the equation: $SP = OP - TP$.
Where $SP$ is Suction Pressure (also known as Diffusion Pressure Deficit or $DPD$),$OP$ is Osmotic Pressure,and $TP$ is Turgor Pressure.
When a cell is fully turgid,the Turgor Pressure $(TP)$ becomes equal to the Osmotic Pressure $(OP)$.
Therefore,$SP = OP - OP = 0$.
Thus,the Suction Pressure $(SP)$ of a fully turgid cell is zero.

(C) The turgidity of a cell is the state in which the cell membrane pushes against the cell wall due to the entry of water.
This pressure exerted by the protoplast against the cell wall due to the entry of water is known as $Turgor \text{ } Pressure$ $(TP)$.
As water enters the cell via osmosis, the cell becomes turgid, and the $TP$ increases, which maintains the shape and rigidity of the cell.

(D) In a fully turgid cell,the cell wall exerts an equal and opposite pressure against the entry of water,making the Turgor Pressure $(TP)$ equal to the Osmotic Pressure $(OP)$.
The formula for Diffusion Pressure Deficit $(DPD)$ is $DPD = OP - TP$.
Since $OP = TP$ in a fully turgid cell,$DPD = OP - OP = 0$.
Therefore,the correct condition is $DPD = 0 \text{ atm}, OP = 15 \text{ atm}, TP = 15 \text{ atm}$.

(A) When a plant cell is placed in a hypotonic solution,water enters the cell via endosmosis,causing the cell to swell and become turgid.
As the cell contents push against the cell wall,they exert a pressure known as turgor pressure $(TP)$.
According to Newton's third law of motion,the rigid cell wall exerts an equal and opposite pressure on the cell contents,which is called wall pressure $(WP)$.
Therefore,as the turgidity of the cell increases,the turgor pressure increases,and consequently,the wall pressure also increases to maintain equilibrium.

(C) Osmotic pressure is directly dependent upon the concentration of solutes within the cell sap.
Xerophytes are plants adapted to survive in environments with limited water availability.
To maintain water uptake from the soil and prevent water loss,these plants maintain a higher concentration of solutes in their cell sap compared to mesophytes.
Therefore,the osmotic concentration in xerophytes is higher (more than normal) to facilitate the absorption of water under dry conditions.

(D) The $DPD$ of a cell is defined as the difference between the diffusion pressure of pure water and the diffusion pressure of the solution.
It is mathematically expressed as: $DPD = OP - TP$.
Since $DPD$ is determined by both $OP$ (Osmotic Pressure) and $TP$ (Turgor Pressure),it does not depend on just one of these factors exclusively.
Therefore,the correct answer is that it depends on both,making 'None of these' the most appropriate choice among the given options.

(D) The osmotic concentration (or osmotic pressure) of a solution is determined by the van't Hoff equation: $\pi = iCRT$.
In this equation:
$1$. $C$ represents the molar concentration of the solute.
$2$. $R$ is the gas constant.
$3$. $T$ is the absolute temperature of the solution.
$4$. $i$ is the van't Hoff factor,which accounts for the degree of ionization of the solute.
Since all these factors ($C$,$T$,and $i$) directly influence the osmotic pressure,the correct answer is all the above.

(A) When water enters a cell through endosmosis,the protoplast swells and exerts pressure against the rigid cell wall. This hydrostatic pressure developed inside the cell is called turgor pressure. It is essential for maintaining the shape and rigidity of plant cells and is responsible for the growth of young cells.

(A) $DPD$ (Diffusion Pressure Deficit) is defined as the difference between the diffusion pressure of pure solvent and the diffusion pressure of the solution.
When mesophyll cells lose water, the concentration of solutes within the cell increases, which decreases the water potential $\Psi_w$ and increases the $DPD$.
Mathematically, $DPD = OP - TP$. As the cell loses water, the Turgor Pressure $(TP)$ decreases, which leads to an increase in the $DPD$ value.

(B) In a turgid cell,the protoplast exerts pressure against the cell wall,which is known as turgor pressure $(TP)$.
To maintain the structural integrity of the cell,the rigid cell wall exerts an equal and opposite pressure on the protoplast,which is known as wall pressure $(WP)$.
Therefore,in a fully turgid cell,$TP = WP$.

(D) In a fully turgid cell,the cell wall exerts an equal and opposite pressure to the turgor pressure,making the net water potential gradient zero.
The relationship is given by the formula: $DPD = OP - TP$.
When a cell is fully turgid,the turgor pressure $(TP)$ becomes equal to the osmotic pressure $(OP)$.
Therefore,$DPD = OP - OP = 0$.
Thus,the correct option is $D$.

(D) The relationship between $DPD$ (Diffusion Pressure Deficit),$OP$ (Osmotic Pressure),and $TP$ (Turgor Pressure) is given by the formula: $DPD = OP - TP$.
If $TP$ is positive,$DPD$ will be less than $OP$.
If $TP$ is zero (flaccid cell),$DPD$ will be equal to $OP$.
If $TP$ is negative (plasmolyzed cell),the formula becomes $DPD = OP - (-TP)$,which simplifies to $DPD = OP + TP$.
Therefore,when $TP$ is negative,$DPD$ becomes greater than $OP$.

(A) The movement of water in plants occurs from a region of lower $DPD$ to a region of higher $DPD$.
Water is absorbed by root hairs from the soil,so root hairs have the lowest $DPD$ among the three to facilitate water entry.
Water then moves from the root hair to the inner cortical cells,and finally towards the mesophyll cells where transpiration creates a high $DPD$ (water deficit).
Therefore,the ascending order of $DPD$ is: Root hair < Cortical cell < Mesophyll.

(C) The movement of water between two cells is determined by the $DPD$ (Diffusion Pressure Deficit) gradient.
The formula for $DPD$ is $DPD = OP - TP$.
Given that both cells have the same $OP$, the difference in $DPD$ depends entirely on the $TP$ (Turgor Pressure).
Water always moves from a region of lower $DPD$ to a region of higher $DPD$.
If $TP$ is higher, $DPD$ becomes lower $(DPD = OP - \text{higher value})$. If $TP$ is lower, $DPD$ becomes higher $(DPD = OP - \text{lower value})$.
Therefore, water moves from the cell with higher $TP$ (lower $DPD$) to the cell with lower $TP$ (higher $DPD$).

(D) When osmotic pressure $(OP)$ becomes equal to the wall pressure $(WP)$,the turgor pressure $(TP)$ is equal to the osmotic pressure.
In this state,the water potential gradient becomes zero,meaning there is no net movement of water into or out of the cell.
Therefore,the cell reaches a state of equilibrium and has no further capacity to absorb any more water.

(A) The movement of water between two adjacent cells is determined by their $DPD$ (Diffusion Pressure Deficit) values.
Water always moves from a region of lower $DPD$ to a region of higher $DPD$.
Since the $DPD$ of cell $X$ is lower than the $DPD$ of cell $Y$,water will move from cell $X$ to cell $Y$.
Therefore,the correct direction of net water movement is $X$ to $Y$.

(B) When a plant cell is placed in a hypotonic solution,water enters the cell due to endosmosis,causing the protoplast to press against the cell wall. This pressure is called Turgor Pressure $(TP)$. The rigid cell wall exerts an equal and opposite pressure on the protoplast,known as Wall Pressure $(WP)$. When the cell becomes fully turgid,$TP = WP$. At this stage,the net movement of water becomes zero,meaning no further exchange of water takes place between the cell and its environment,establishing a state of equilibrium.

(C) The osmotic pressure $(OP)$ of a solution can be calculated using the formula $OP = CRT$, where $C$ is the molar concentration, $R$ is the gas constant $(0.0821 \, L \, atm \, K^{-1} \, mol^{-1})$, and $T$ is the absolute temperature in Kelvin.
For a $1 \, M$ (molar) solution at $0^o C$ $(273 \, K)$:
$OP = 1 \, mol/L \times 0.0821 \, L \, atm \, K^{-1} \, mol^{-1} \times 273 \, K \approx 22.4 \, \text{atmospheres}$.
Therefore, an ideal molar solution at $0^o C$ exerts an osmotic pressure of approximately $22.4 \, \text{atmospheres}$.

(A) Osmotic pressure $(OP)$ is defined as the pressure that must be applied to a solution to prevent the inward flow of its pure solvent across a semipermeable membrane.
When water moves through a semipermeable membrane due to a concentration gradient,the pressure required to stop this movement is known as the osmotic pressure $(OP)$.

(A) When a plasmolysed cell is placed in a hypotonic solution,the water potential of the external solution is higher than that of the cell sap.
This creates a gradient that causes water to enter the cell through endosmosis.
The force responsible for this movement is the Diffusion Pressure Deficit $(DPD)$,which is also known as Suction Pressure $(SP)$.
$DPD$ represents the thirst of the cell to absorb water,and as water enters,the cell regains its turgidity and original shape.

(A) Osmotic pressure is defined as the pressure required to prevent the flow of solvent into a solution through a semi-permeable membrane. Pure solvent (like pure water) has an osmotic pressure of $0$. When a solute is added to a solvent to form a solution,the osmotic pressure of the solution increases. Therefore,the osmotic pressure of a solution is always greater than that of a pure solvent.

(A) Osmotic pressure is defined as the pressure required to prevent the movement of solvent molecules into a solution through a semi-permeable membrane.
Pure solvent has an osmotic pressure of $0$ (or is considered to have the lowest potential).
When solutes are added to a solvent to form a solution,the osmotic pressure increases.
Therefore,the osmotic pressure of a solution is always greater than that of a pure solvent.

(B) Water absorption by root hairs occurs primarily through osmosis,which is driven by a water potential gradient.
For water to move from the soil into the root xylem,the water potential of the soil must be higher than that of the root cells.
This corresponds to a situation where the osmotic pressure of the xylem sap is significantly higher than that of the soil water.
Therefore,a larger difference between the osmotic pressure of the soil water and the xylem vessels creates a steeper gradient,leading to a faster rate of water absorption.

(D) Osmotic pressure is the pressure required to prevent the movement of water across a semi-permeable membrane into a solution.
It is directly proportional to the concentration of the solute particles in the solution.
As the concentration of the solute increases,the osmotic pressure also increases.
Since the concentration of the solution is defined by the amount of solute dissolved in a given volume of solvent,the osmotic pressure depends on the solute concentration,the solvent concentration,and the overall concentration of the solution.
Therefore,all the given factors are interrelated and contribute to the osmotic pressure.

(C) Water moves from a region of lower $DPD$ to a region of higher $DPD$. The force that drives water into a cell is equal to the difference between the Osmotic Pressure $(OP)$ and the Turgor Pressure $(TP)$. This is known as the Diffusion Pressure Deficit $(DPD)$. The relationship is expressed as $DPD = OP - TP$.

(C) Osmotic pressure is the pressure required to prevent the movement of water across a semi-permeable membrane into a solution.
According to the van't Hoff equation, osmotic pressure $\pi$ is directly proportional to the concentration of solute particles in the solution $\pi = iCRT$.
Therefore, as the concentration of solute increases, the osmotic pressure of the solution also increases.

(C) The absorption of water by root hairs from the soil is primarily driven by the $Diffusion Pressure Deficit$ $(DPD)$,which is also known as $Suction Pressure$ $(SP)$.
Water moves from a region of higher water potential (soil) to a region of lower water potential (root hair cells).
The $DPD$ of the root hair cell is higher than that of the soil water,creating a gradient that pulls water into the root.
Therefore,$Suction Pressure$ is the correct term describing the force responsible for water uptake.

(C) The correct answer is $C$.
Diffusion pressure deficit $(DPD)$ is the reduction in the diffusion pressure of water in a system compared to its pure state.
It is calculated using the formula: $DPD = O.P. - T.P.$
For cell $A$: $DPD = 10 \ atm - 7 \ atm = 3 \ atm$.
For cell $B$: $DPD = 8 \ atm - 3 \ atm = 5 \ atm$.
Water always moves from a region of lower $DPD$ to a region of higher $DPD$.
Since cell $A$ has a lower $DPD$ $(3 \ atm)$ and cell $B$ has a higher $DPD$ $(5 \ atm)$,water will move from cell $A$ to cell $B$.

(C) The movement of water molecules across a semi-permeable membrane from a region of higher water potential to a region of lower water potential is known as osmosis.
Osmotic Pressure $(O.P.)$ is the pressure that must be applied to a solution to prevent the inward flow of water across a semi-permeable membrane.
When water moves through a semi-permeable membrane,it is driven by the osmotic gradient,and the pressure associated with this phenomenon is $O.P.$

(A) Osmotic pressure is the pressure required to prevent the movement of water across a semi-permeable membrane into a solution.
According to the van't Hoff equation, osmotic pressure $(\pi)$ is directly proportional to the concentration of solute particles in the solution, represented as $\pi = iCRT$, where $C$ is the molar concentration of the solute, $R$ is the gas constant, and $T$ is the absolute temperature.
Therefore, the higher the concentration of solutes, the higher the osmotic pressure of the solution.

(A) When a plant cell is placed in a hypotonic solution (water),water enters the cell due to endosmosis.
As water enters,the protoplast expands and pushes against the cell wall.
This pressure exerted by the protoplast against the cell wall is called turgor pressure.
Consequently,the cell wall exerts an equal and opposite pressure on the protoplast,known as wall pressure.
Therefore,the pressure on the cell wall increases as the cell becomes turgid.

(C) When water moves through a semi-permeable membrane due to osmosis,it exerts pressure against the cell wall,which is known as $Turgor \ Pressure \ (T.P.)$.
$Osmotic \ Pressure$ is the pressure required to prevent the movement of water,while $Turgor \ Pressure$ is the actual physical pressure exerted by the protoplast against the cell wall due to the entry of water.
Therefore,the force generated by the movement of water into the cell is $Turgor \ Pressure$.

(C) The movement of water is determined by the Diffusion Pressure Deficit $(DPD)$.
Water always moves from a region of lower $DPD$ to a region of higher $DPD$.
Given for cell $A$: $DPD_A = 3 \text{ atm}$.
Given for cell $B$: $DPD_B = 5 \text{ atm}$.
Since $DPD_A < DPD_B$ $(3 \text{ atm} < 5 \text{ atm})$,water will move from cell $A$ to cell $B$ because cell $A$ has a higher water potential compared to cell $B$.

(C) The formula for $DPD$ is $DPD = OP - TP$.
Given values for cell $A$: $DPD = 4 \, \text{bars}$.
For cell $B$: $OP = 4, TP = 4 \implies DPD = 4 - 4 = 0 \, \text{bars}$.
For cell $C$: $OP = 10, TP = 5 \implies DPD = 10 - 5 = 5 \, \text{bars}$.
For cell $D$: $OP = 7, TP = 3 \implies DPD = 7 - 3 = 4 \, \text{bars}$.
Water always moves from a region of lower $DPD$ to a region of higher $DPD$.
Comparing the values: $B(0) < A(4) = D(4) < C(5)$.
Therefore, water will flow from cell $B$ (lowest $DPD$) towards cells $A, D,$ and $C$ (higher $DPD$).

(A) Pressure potential,also known as positive hydrostatic pressure or turgor pressure,is the pressure that develops within a cell due to the osmotic entry of water.
When water enters a plant cell,the protoplast expands and exerts pressure against the rigid cell wall.
This outward pressure is known as turgor pressure.

(C) The term $DPD$ (Diffusion Pressure Deficit) was coined by the scientist $Meyer$ in $1938$. It represents the difference between the diffusion pressure of pure water and the diffusion pressure of a solution.

(C) The net force with which water is drawn into a cell or root hair is equal to the difference between $OP$ and $TP$,which is known as $DPD$ (Diffusion Pressure Deficit) or suction pressure.
Water always moves from a region of lower $DPD$ to a region of higher $DPD$.
The formula is given by: $DPD = OP - TP$.

(A) When a plasmolyzed cell is placed in a hypotonic solution (a solution with lower osmotic pressure than the cell sap),water enters the cell due to the $DPD$ (Diffusion Pressure Deficit).
$DPD$ represents the difference between the osmotic pressure $(OP)$ and the turgor pressure $(TP)$ of the cell.
Since a plasmolyzed cell has a very high $DPD$ and a turgor pressure of zero,the water potential gradient drives water into the cell,causing it to regain its normal shape and size.

(A) When a plant cell is placed in a hypotonic solution or pure water,water enters the cell through endosmosis.
As the volume of the protoplast increases,it exerts an outward pressure against the cell wall,known as turgor pressure $(TP)$.
According to the physical laws of the cell,the cell wall exerts an equal and opposite pressure on the protoplast,which is known as wall pressure $(WP)$.
Therefore,as the turgidity of the cell increases,the turgor pressure increases,which consequently causes the wall pressure to increase.

(B) Pure water has the maximum diffusion pressure. When solute particles are added to pure water,the kinetic energy of water molecules decreases,which lowers the diffusion pressure. This reduction in the diffusion pressure of water in a solution compared to its pure state is known as Diffusion Pressure Deficit $(DPD)$.

(C) The Diffusion Pressure Deficit $(DPD)$ is defined as the difference between the Osmotic Pressure $(OP)$ and the Turgor Pressure $(TP)$ (or Wall Pressure,$WP$) of a cell.
The formula is given by: $DPD = OP - TP$ or $DPD = OP - WP$.
In a fully turgid cell,the $OP$ is equal to the $TP$,so the $DPD$ becomes zero.
Therefore,the correct expression representing $DPD$ is $OP - WP$.

(D) The difference between the diffusion pressure of a solution and its pure solvent at a particular temperature and atmospheric pressure is called $DPD$ (Diffusion Pressure Deficit).
$DPD$ is also known as suction pressure $(SP)$.
The relationship is given by the formula: $DPD = OP - TP$.
In a fully turgid cell,the turgor pressure $(TP)$ becomes equal to the osmotic pressure $(OP)$.
Therefore,$DPD = OP - TP = 0$.

(D) The relationship between $DPD$,$OP$,and $TP$ is given by the formula: $DPD = OP - TP$.
For cell-$A$: $DPD = 10 \text{ atm} - 7 \text{ atm} = 3 \text{ atm}$.
For cell-$B$: $DPD = 8 \text{ atm} - 3 \text{ atm} = 5 \text{ atm}$.
Water always moves from a region of lower $DPD$ to a region of higher $DPD$ (or from higher water potential to lower water potential).
Since cell-$A$ has a $DPD$ of $3 \text{ atm}$ and cell-$B$ has a $DPD$ of $5 \text{ atm}$,water will move from cell-$A$ to cell-$B$.

(A) When water enters a plant cell through osmosis,it exerts pressure against the cell wall,which is known as turgor pressure.
This pressure is always positive in a turgid plant cell because it pushes the plasma membrane against the cell wall.
Therefore,the hydrostatic pressure that develops due to the entry of water is positive.

(A) Turgor pressure $(TP)$ is the pressure exerted by the protoplast against the cell wall due to the entry of water into the cell.
Since the protoplast pushes against the cell wall,it is a positive pressure.
Therefore,$TP$ is a positive pressure.