Question

how does humidity affect the opening and closing of stomata

Answer 1

Humidity affects the opening and closing of stomata. Stomatal pores remain open under high humidity condition, whereas get closed under low humidity conditions. Under low humidity condition, rate of transpiration increases and plant may get wilt. So, to prevent such damages, plants have evolved mechanism that can lead to closure of stomatal pores, minimising rate of transpiartion under low humidity. Ultimately, it is the turgor pressure of guard cells which controls the stomatal opening and closing. Stomata open when guard cells are fully turgid and closes when they are flaccid. So, during stomatal opening, water enters the guard cells through osmosis and vice versa.