NEET2013BotanyTransport in PlantsActual
Which of the following statements is not true for stomatal apparatus?
Options
- AGuard cells invariably possess chloroplasts and mitochondria.
- BGuard cells are always surrounded by subsidiary cells.
- CStomata are involved in gaseous exchange.
- DInner wall of guard cells are thick.
Correct answer
B. Guard cells are always surrounded by subsidiary cells.
Step-by-step solution
The stomata are bordered by two specialized epidermal cells - the guard cells which in some cases are accompanied by subsidiary cells. The walls of guard cells are unevenly thickened. Each guard cell has thick, inelastic inner wall and thin, elastic outer wall, containing chloroplasts. Stomatal aperture is present in between the guard cells. Guard cells are not always surrounded by accessory cells or subsidiary cells. Related Theory The specialized epidermal cells which surround the guard cells are known as subsidi