Photosynthesis of maize plant differs from wheat plant in

Plants in which the first product of $CO_{2}$ fixation is $C_{3}$ acid,i.e.,the ...$A$... pathway,and those in which the first product was $C_{4}$ acid $(OAA)$,i.e.,the ...$B$... pathway. Complete the given statement by filling appropriate options in the given blanks.

Which of the following fixes $CO_2$ in carbohydrates?

Which of the following statements is/are not true?
$I.$ In $CAM$ plants,stomata open during dark and remain closed during the day.
$II.$ Role of $Na^+$ in stomatal opening is now universally accepted.
$III.$ The water potential of root cells is higher than the water potential of soil.
$IV.$ Capillarity theory is the most accepted theory of water movement through plants.
$V.$ The walls of xylem vessels made up of ligno-cellulose have strong affinity for water molecules.

Which of the following is correct for photosynthesis?

$CO_2$ is constantly released in respiration,yet its level remains fairly uniform because: