Which hormone is concerned chiefly with cell division in plants?

Apical dominance is stimulated by auxin,whereas it is inhibited by:

Which of the following helps in delaying leaf senescence?

Which of the following plant hormones is responsible for delaying the senescence of plant organs?

Which chemical must be applied to the roots to keep the leaves of a plant green?

$A$ : Cytokinin along with the auxin are required for morphogenesis.
$R$ : More cytokinin to auxin ratio promotes root initiation during micropropagation.