The Question is from neet-botany plant-physiology , and it was created by the author B VENKAT

Question

Two identical plant cells are placed in separate solutions. Cell A is placed in a 1M sucrose solution, and Cell B is placed in a 1M NaCl solution.  Which cell will experience greater plasmolysis, assuming ideal conditions and complete dissociation of NaCl?

B VENKAT · Accepted Answer

## CORE INFORMATION
✓ **Answer**: B
## CONCEPT FRAMEWORK
 **Primary Concept**: Plasmolysis and Osmosis
 **Related Topics**: Water potential, solute potential, pressure potential, tonicity
 **Prerequisites**: Understanding of osmosis and how it affects plant cells.
## SOLUTION PATHWAY
**Given Information**:
  * Two identical plant cells
  * Cell A in 1M sucrose solution
  * Cell B in 1M NaCl solution
  * Complete dissociation of NaCl
  * Ideal conditions
**Method & Steps**:
 1. **Understanding Plasmolysis**: Plasmolysis occurs when water leaves the cell due to a higher solute concentration outside the cell, causing the cell membrane to shrink away from the cell wall.
  Reasoning: The extent of plasmolysis depends on the difference in water potential between the cell and its surrounding solution.
  Formula/Rule: Water moves from a region of higher water potential to a region of lower water potential.
 2. **Comparing Solute Concentrations**:  NaCl completely dissociates into two ions (Na+ and Cl-), resulting in a higher effective solute concentration in solution B compared to solution A.  A 1M NaCl solution has an osmotic pressure equivalent to a 2M solution of a non-dissociating solute like sucrose.
  Working: Sucrose is a non-electrolyte, meaning it doesn't dissociate in solution.  Therefore, the solution around cell A has an effective solute concentration of 1M. The solution around cell B has an effective solute concentration of 2M because NaCl dissociates into two ions.
  Key Point:  The effective osmotic pressure is determined by the total number of solute particles, not just the molar concentration.
 3. **Determining Greater Plasmolysis**: Since the solution surrounding cell B has a higher effective solute concentration (2M equivalent), the water potential outside cell B is lower than outside cell A.  This leads to a greater outward movement of water from cell B, resulting in more significant plasmolysis.
  Result: Cell B will experience greater plasmolysis.
  Verification: The higher the osmotic pressure of the external solution, the greater the water loss from the cell and thus the greater the plasmolysis.
 ## OPTION ANALYSIS
A :x: Cell A experiences plasmolysis, but less than cell B because of the lower effective solute concentration.
B ✓: Cell B experiences greater plasmolysis due to the higher effective solute concentration from the dissociated NaCl.
C :x: The effective solute concentrations are different, leading to unequal plasmolysis.
D :x: Both cells will experience plasmolysis because they are placed in hypertonic solutions.
 ## LEARNING AIDS
 **Common Mistakes**:
  1.Ignoring the dissociation of NaCl:  Failing to account for the two ions from NaCl leads to an incorrect comparison of solute concentrations.
  2.Confusing water potential and solute concentration: While related, they are not directly interchangeable. Water potential also considers pressure potential.
 **Quick Tips**:
  1.Remember that electrolytes dissociate, increasing the effective osmotic pressure.
  2.Visualize the water movement across the cell membrane to understand plasmolysis.

B VENKAT · Answer

Cell A

B VENKAT · Answer

The correct Option is "Cell B"

B VENKAT · Answer

Both cells will plasmolyze equally

B VENKAT · Answer

Neither cell will plasmolyze

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