Question

During opening of stomata, influx of $K^{+}$ ions into the guard cells is accompanied with efflux of

• A. $N{a}^{+}$
• B. $K^{+}$
• C. $C{l}^{-}$
• D. $H^{+}$

Answer 1

Answer: (D)

According to active $K^{+}$ ion transport theory, during day time, $C{O}_2$ concentration decreases due to it being used up in photosynthesis. Malic acid is formed in guard cells which dissociates into malate ions and $H^{+}$. $K^{+}$ ions exchange with $H^{+}$ ions from cytoplasm of guard cells.