▶️ Answer/Explanation
Water always moves from a region of higher water potential (less negative value) to a region of lower water potential (more negative value) down a water potential gradient. In option B, the water potentials are $-350 \rightarrow -400 \rightarrow -450 \rightarrow -600$. Since $-350$ is the highest value and $-600$ is the lowest, the water will flow from left to right ($W$ to $Z$). This matches the direction arrow provided in the row. In other options, the values either increase in the direction of the arrow or the arrow contradicts the gradient.
✅ Answer: (B)
✅ Answer: (B)
▶️ Answer/Explanation
When a plant cell is placed in a solution with a lower water potential (a hypertonic solution), water moves out of the cell down the water potential gradient via osmosis. As the central vacuole loses water, the volume of the protoplast decreases, causing the cell membrane to pull away from the cell wall. This loss of internal pressure (turgor pressure) causes the cell to become soft or limp, a state known as being flaccid. If the process continues, the cell may eventually undergo plasmolysis.
✅ Answer: (C)
✅ Answer: (C)
▶️ Answer/Explanation
Water moves via osmosis from a region of higher water potential to a region of lower water potential across a partially permeable membrane. If the sugar solution has a higher water potential than the potato tissue, water will enter the potato cells. This influx of water increases the turgor pressure and causes the potato stick to expand and increase in length. At the start, all sticks were $10$ squares long. In dish D, the stick has grown to $11$ squares, indicating it absorbed water from the surrounding solution. In contrast, sticks in A, B, and C decreased in length, meaning they lost water to a lower water potential solution.
✅ Answer: (D)
✅ Answer: (D)