Which scientist coined the term 'kinetin'?

$6-$ furfuryl adenine is

Cytokinins are said to be anti-ageing hormones because they delay senescence by:

Delay of senescence or Richmond-Lang effect is a physiological effect of:

Study the following statements:
$I.$ Cytokinins are formed primarily in roots.
$II.$ Auxin and cytokinin are antagonistic in apical dominance.
$III.$ Kinetin (a modified $DNA$ purine) was discovered from herring sperm.
$IV.$ Zeatin is auxin.
$V.$ Zeatin was firstly extracted from herring.
Choose the incorrect one.

Cytokinin helps in delaying leaf senescence mainly by