Stomata open and close in response to -

Question

Responses

water being pumped in and out of guard cells
water being pumped in and out of guard cells, ,

crystal formation in the plant due to excess glucose.

, crystal formation in the plant due to excess glucose.,

the lack of available sunlight during the night
the lack of available sunlight during the night, ,

stimulation by auxins producing rapid growth
stimulation by auxins producing rapid growth, ,

Answer 1

changes in temperature and humidity levels.