Which one of the following phytohormones promotes nutrient mobilization which helps in the delay of leaf senescence in plants?

Define/Explain: Cytokinins.

Farmers in a particular region observed that during the cultivation of pulse crops,the leaves become yellow and underdeveloped,leading to a decrease in yield. Which treatment can result in higher seed production?

Which of the following induces cell division in a cell?

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.

Explain the plant hormone discovered from the sperm of herring fish.