Water Potential Differences in Xerophytic Leaf Layers

Steps:

• Evaluate statement 1: In drier condition P, water potential in layer Y cells is more negative due to water loss compared to wetter Q.
• Evaluate statement 2: More negative water potential in P causes greater water efflux, leading to more plasmolyzed cells than in Q.
• Evaluate statement 3: Cells are more turgid in Q (higher water potential) than in P, so they are not less turgid in Q.
• Evaluate statement 4: Water potential in plant cells rarely reaches zero (pure water level); Q likely has negative but less so than P.

Why B is correct:

• B selects statements 1 and 2, which align with water potential gradient driving osmosis and plasmolysis in drier P versus Q.

Why the others are wrong:

• A includes false statement 3, inverting turgor comparison.
• C includes false statement 4, as zero water potential is unrealistic for cells.
• D combines false statements 3 and 4.

Final answer: B