In which of the following are stomata absent?

In scotoactive opening of stomata,they remain open during

Which one of the following describes a possible reason for the opening and closing of the guard cells?

Which of the following statements is not true for stomatal apparatus?

$(i)$ The ...$a$... help in maintaining the pressure gradient in the sieve tubes.
$(ii)$ Stomata regulate the process of ....$b$..... and gaseous exchange.

The opening and closing of stomata takes place as a result of active transport of . . . . . . ions in guard cells.