Question

Which one is responsible for opening of stomata ?

• A. Decrease in CO${}_2$ concentration and increase in H${}^{+}$ ion concentration
• B. Decrease in CO${}_2$ concentration and decrease in H${}^{+}$ ion concentration
• C. Increase in CO${}_2$ concentration and increase in H${}^{+}$ ion concentration
• D. More free H${}^{+}$ ions and less Cl${}^{-}$

Answer 1

Answer: (B)

Decrease in CO${}_2$ concentration and decrease in H${}^{+}$ ion concentration

Opening and closing of stomata depend on several factors like light, pH, solute concentration etc.

pH governs stomatal opening as the decrease in carbon dioxide and the decrease in hydrogen ion concentration leading to the opening of stomata.

So, the correct answer is 'Decrease in carbon dioxide concentration and a decrease in H+ ion concentration'.