Cambridge O Level Biology · Syllabus 5090 · Transport in Flowering Plants
Wilting
What is Wilting?
The drooping of the leaves and soft stems of a plant that occurs when water is lost from the leaves faster than it is taken up by the roots. The cells lose water by osmosis, their vacuoles become smaller, the turgor pressure of the cell contents against the cell wall falls and the cells become flaccid. Because turgid cells are what hold soft plant tissue rigid, the tissue loses its support and the leaves and stem droop. Wilting is often reversible: if water is supplied, the cells regain turgor and the plant recovers.
This definition is part of the Transport in Flowering Plants chapter in Cambridge O Level Biology.
Common mistakes with Wilting
- 14. “The plant has wilted, so it has died.” Why wrongWilting is a loss of turgor, and it is usually reversible. Water the plant and the cells take up water by osmosis and become turgid again. WriteWilting occurs when water loss exceeds water uptake, so cells become flaccid and the tissue loses support; prolonged wilting damages the plant, but drooping alone does not mean death.
Questions students ask about Wilting
Why does a plant wilt?
Because water is being lost from the leaves faster than the roots can take it up. The cells lose water by osmosis, their vacuoles become smaller and turgor pressure falls, so the cells become flaccid. Turgid cells are what hold soft plant tissue rigid, so the leaves and stems lose their support and droop. Wilting is usually reversible once water is supplied.