Question

Is guard cell a closed shaped barrel cell

Answer 1

Guard cells usually keep stomata open during the day and closed at night because during the night there is no sunlight for photosynthesis. If the stomata were open at night, very little gas exchange would occur, but water loss would still continue. Temperature also signals guard cells.

Answer 2

$\huge{\underline{\underline{\boxed{\sf{\purple{Yes}}}}}}$