The result of placing a plant cell in a hypertonic solution for a long time is ________of the cell.

Analyze the question: A plant cell is placed in a hypertonic solution (one with a higher solute concentration than the cell sap) for a long time. We need the effect on the cell.

Concept: Osmosis is the movement of water from a region of higher water potential (dilute solution) to a region of lower water potential (concentrated solution) through a semi-permeable membrane.

• Hypotonic surroundings: water enters the cell, which becomes turgid.
• Isotonic surroundings: there is no net movement of water, and the cell is stable.
• Hypertonic surroundings: water leaves the cell, so the cell loses turgor.

Step-by-step solution:

1. The outside solution is more concentrated than the cell sap, so water moves out of the cell by osmosis.
2. The vacuole shrinks and the cytoplasm loses water.
3. The cell loses turgor pressure and becomes flaccid.
4. If this continues for a long time, the cell membrane pulls away from the cell wall. This is plasmolysis, which is the extreme stage of flaccidity.

Checking the options:

• A. Crenation is the shrinking of animal cells (e.g. red blood cells) in a hypertonic solution. Plant cells have walls, so this is not the term used.
• B. Flaccidity is the loss of turgor in a plant cell. This is correct.
• C. Haemolysis is the bursting of red blood cells in a hypotonic solution, so it is wrong.
• D. Turgidity happens in a hypotonic solution, so it is the opposite of what is asked.
• E. Vasodilation is the widening of blood vessels and has nothing to do with osmosis.

Exam tip: Remember the pairs:

• Plant cell in hypotonic solution → turgid
• Plant cell in hypertonic solution → flaccid/plasmolysed
• Animal cell in hypotonic solution → haemolysis (bursts)
• Animal cell in hypertonic solution → crenation (shrinks)

Whenever you see "plant" together with "hypertonic", think of water leaving and the cell going limp.