# A student investigates the effect of placing plant cells in solutions of different concentrations. When cells are placed in a very concentrated sugar solution, plasmolysis occurs. Explain what happens to a plant cell during plasmolysis and why this results in cell death.

> OCR A-Level Biology B — Advancing Biology (H422) — 2.2 Biological molecules including biochemistry · Explain · 5 marks

> Plant cells behave differently depending on the concentration of the solution surrounding them. When a plant cell is placed in a concentrated sugar solution, the net movement of water out of the cell causes a sequence of observable changes.

## Mark scheme (5 marks)

1. The solution outside the cell is more concentrated than inside the cell (higher solute concentration / lower water concentration outside)
2. Water moves out of the cell by osmosis through the partially permeable membrane
3. The vacuole shrinks / the cell loses water causing the cell contents to decrease in volume
4. The cell membrane pulls away from the cell wall
5. Cell death results because the cell membrane can no longer function / maintain cellular processes once it has detached from the wall

## Key terms

- [plasmolysis](https://www.gradenine.co.uk/glossary/plasmolysis)

## Related

- [Revision notes for OCR A-Level Biology B — Advancing Biology (H422)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/a-student-investigates-the-effect-of-d46e181b) · Published by Druglandscape Ltd.