[Campbell Biology P.852] What is the immediate physiological event that leads to the opening... | Practice Question

What is the immediate physiological event that leads to the opening of stomata?

  • A: Release of abscisic acid from guard cells.
  • B: Increase in CO2 concentration within the leaf.
  • C: Uptake of K+ by guard cells, leading to increased turgor.
  • D: Loss of water from guard cells, causing them to become flaccid.

Explanation

Stomata open when guard cells take up K+, which lowers their water potential, causing water to move into them by osmosis. This increased turgor pressure causes the guard cells to bow outward, opening the stomatal pore.