Question

The shape of guard cells changes due to change in the:

• A. protein composition of cells
• B. temperature of cells
• C. amount of water in cells
• D. position of the nucleus in the cells

Answer 1

The correct option is C

amount of water in cells

The correct option is C.

Explanation of the correct option:

1. Guard cells are cells surrounding the stomatal pores.
2. Stomata regulate the process of transpiration and gaseous exchange.
3. Guard cells regulate the opening and closing of stomata.
4. The outer walls of guard cells are thin and their inner walls are thickened.
5. This unequal thickening of guard cells causes the stomata to open and close.
6. When water flows into the guard cells, it swells up and causes the stomata to open.
7. When the guard cells lose water, they shrink and become flaccid and straight causing the closure of stomata.

Final answer: The shape of guard cells changes due to a change in the amount of water in cells.