$A$ physiological xerophyte is

What is a $Cactushouse$?

Match the following columns:

Column-$I$	Column-$II$
$P$. Indole compounds	$I$. $IAA$
$Q$. Adenine derivatives	$II$. $ABA$
$R$. Carotenoid derivatives	$III$. $GA_3$
$S$. Terpenes	$IV$. Kinetin
$T$. $C_2H_4$	$V$. Ethylene

Opening of flower is an example of

Name a hormone which:
$(A)$ is gaseous in nature
$(B)$ is responsible for phototropism
$(C)$ induces femaleness in flowers of cucumber
$(D)$ is used for killing weeds (dicots)
$(E)$ induces flowering in long day plants

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