Question

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

Hint: A plant cell is the eukaryotic cells that are found in the green plants. They are the functional units of the plant for performing various functions such as photosynthetic activities, transpiration and production of fruits, flowers and seeds.

Complete answer:
The plant cells are the basic units of the plants and they are attributed to perform different functions. The plants are the food producing organisms who can make their own food through the process of photosynthesis. Different functions of the plant are performed by different types of specialized cells.

The structure of the plant cells includes primary cell walls which contains cellulose, hemicellulose and pectin, and it bounds the other cell organelles such as ribosomes, endoplasmic reticulum, golgi, mitochondria as plastids and vacuoles. The plastids are the organelles that possess photosynthetic ability and can also store starch. The vacuole present in the plant cells are responsible for maintaining and regulating the turgor pressure by controlling the movement of molecules between the cytosol and the sap.

Turgor pressure can be defined as the force within the cell that causes the plasma membrane to push against the cell wall. It is also known as hydrostatic pressure. It is caused by the osmotic flow of water and commonly occurs in plant cells, fungi and bacteria. The turgor pressure in normal condition is equal to the pressure of water inside the cell. The turgor pressure is regulated by the process of osmosis which allows the water to insert inside the cell and this causes the cell to expand. Due to the expansion of the cell, it creates a pressure on the cell wall and when the turgor pressure is higher than the pressure of the cell wall causes the cell to burst. During water loss, the turgor pressure is very less than the water pressure and as water moves out, it decreases the turgor pressure of the cell and the cell seems to be shrunken.

Hence, the correct answer is option (B).

Note: The turgor pressure is important in maintaining the stable and natural shape of the plant cells. It is generally regulated through the process of osmosis. The semi permeable nature of the plasma membrane helps to maintain the passage of the solute and helps to maintain minimum pressure. The excess turgor pressure creates a pressure on the cell wall and causes the cell wall to burst. The minimum level of turgor pressure can cause the cell to lose its shape and appear shrunken.