Question

Choose the correct answer from each of the four options given below

A plant cell may burst when

• A. turgor pressure equalizes wall pressure
• B. turgor pressure exceeds wall pressure
• C. wall pressure exceeds turgor pressure
• D. None of the above

Answer 1

The correct option is B

turgor pressure exceeds wall pressure

Explanation of the correct option :

The correct option is B:

1. A cell when it cannot accommodate more water in it, then it is said to be a turgid cell.
2. Two kinds of pressures are generated by a turgid cell, namely turgor pressure, and wall pressure.
3. Turgor pressure is the pressure exerted by the protoplasm against the cell wall in order to maintain the shape of the cell.
4. Wall pressure is the backpressure exerted by the cell wall against the protoplasm of a fully turgid cell.
5. Normally in this condition, wall pressure is equal and opposite to turgor pressure.
6. When there is endosmosis, there is the entry of water into the cell which increases the turgor pressure.

Thus, if the turgor pressure exceeds the wall pressure, the plant cell will burst.

Explanation of the incorrect options :

Option A:

When wall pressure is equal to and opposite to turgor pressure then the cell is in a turgid state.

Option C:

1. When wall pressure is more than the turgor pressure then the cell starts to lose water.
2. This is the process of exosmosis which leads to a flaccid cell.
3. It is basically a reversal of turgidity.

A plant cell may burst when turgor pressure exceeds wall pressure.