The phytohormone combination which is the key regulator of cell differentiation and morphogenesis is

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

An annual plant differs from a biennial plant by ..........

Choose the correct statement:
$I.$ Cytokinin - Delay of leaf senescence
$II.$ Auxin - Apical dominance
$III.$ Ethylene - Seed germination
$IV.$ Gibberellins - Immature falling of leaves

You are given a tissue with its potential for differentiation in an artificial culture. Which of the following pairs of hormones would you add to the medium to secure shoots as well as roots?

Factors which can modify geotropic responses are