Name the plant hormones responsible for the following

(a) elongation of cells

(b) growth of stem

(c) promotion of cell division

(d) falling of senescent leaves

(a) Auxin is a plant hormone produced in the stem tip that promotes cell elongation.

(b) Gibberellin is a plant hormone that causes growth of stem.

(c) Cytokinin is a plant hormone that promotes cell division.

(d) Abscisic acid is a plant hormone that controls falling of senescent leaves.