Q. Identify the correct statements from the following: I.Accumulation of $K^{+}$ ions in the guard cells does not require energy. II.A high pH favours stomatal opening. III.Movement of chloride ions into the guard cells accrues in the response to the electrical differential created by $K^{+}$ ions. IV.With the entry of several $K^{+}$ ions and chloride ions, the water potential of guard cells increases.
A) I and III
B) I and II
C) II and III
D) III and IV
Explanation
In the light, the pH of guard cells becomes increased due to consumption of $CO_{2}$ in the process of photosynthesis. Guard cells receive $K^{+}$ions from subsidiary cells. This decreases the water potential of guard cells and leads to migration of water from subsidiary cells to guard cells. Uptake of $K^{+}$ ions is also balanced by $Cl^{-}$ ions.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.