Guard cells are specialized cells in the epidermis of leaves, stems and other organs that are used to control gas exchange, including water vapor via transpiration. guard cells perceive and process environmental stimuli to trigger cellular responses resulting in stomatal opening or closure. all but one environmental stimuli might trigger stomatal opening. that would be group of answer choices
a. auxins.
b. co2.
c. cold.
d. light.

Which of the following matches the organisms described with the correct domain? a. archaea--multicellular, eukaryotic organisms that do not have cell walls b. eukarya--single-celled and multicellular organisms, with a defined nucleus and a variety of nutritional sources c. bacteria--unicellular, eukaryotic organisms with cell walls that do not contain peptidoglycan d. bacteria--unicellular, eukaryotic organisms that always lack cell walls