Q.) Opening and closing of stomatal pore
(a) Atmospheric temperature
(b) oxygen concentration around stomata
(c) carbon dioxide concentration around stomata
(d) water content in the guard cells
Ans. (d) water content in the guard cells
Explanation: The opening and closing of the stomatal pore is a function of the guard cells. The stomatal pore opens when the guard cells swell when water flows into them and closes if the guard cells shrink when water flows out of them.