What is the full form of $IAA$?

Bean seeds were planted and put on a sunny windowsill. As the plants grew,their stems bent toward the window. This bending was most likely caused by an

Which of the following trace elements is essential for auxin synthesis in plants?

Water can be absorbed from a hypertonic external solution by

Identify the functions of auxin and choose the correct option.
$I.$ Initiate rooting in stem cuttings
$II.$ Promote flowering in pineapples
$III.$ Controls xylem differentiation

Which plant hormone prevents the premature shedding of leaves and fruits but promotes the abscission of older,mature leaves and fruits?