$A$ green plant turns pale when transferred to prolonged darkness. It represents a phenomenon called

Phytohormones are used in:

Which one of the plant growth regulators would you use if you are asked to:
$(a)$ Induce rooting in a twig
$(b)$ Quickly ripen a fruit
$(c)$ Delay leaf senescence
$(d)$ Induce growth in axillary buds
$(e)$ 'Bolt' a rosette plant
$(f)$ Induce immediate stomatal closure in leaves.

Clinostat is the apparatus used to

Desert can be converted into greenland by

Match the following columns:

Column-$I$	Column-$II$
$A$. Plant growth promoters	$1$. Auxin
$B$. Plant growth inhibitor	$2$. Gibberellin
	$3$. Abscisic acid
	$4$. Cytokinin

Select the correct matching for $A$ and $B$.