Question

Which is not true regarding stomata?

• A. They are turgor operated valves
• B. Have differentially thickened walls of guard cells
• C. They close when guard cells are turgid
• D. Show scotoactive opening in CAM plants

Answer 1

The correct option is C They close when guard cells are turgid

Stomata are composed of two guard cells. These cells have walls that are thicker on the inner side than on the outer side. This unequal thickening of the paired guard cells causes the stomata to open when they take up water and close when they lose water. When guard cells are turgid, stomata opens and closes when guard cells are flaccid.

CAM plants open stomata during night and close during the day. This type of stomata are called scotoactive stomata.