Question

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.

Answer 1

Plant hormones responsible for the following functions are enlisted as below:

S.No	Function	Plant Hormone
01	Elongation of cells	Auxins
02	Growth of stem	Gibberellins
03	Promotion of cell division	Cytokinins
04	Falling of senescent leaves	Abscisic acid

Auxins: -

1. The Auxin was the first phytohormone to be identified, and it was found by biologist Charles Darwin.
2. One of the most crucial plant hormones is called auxin.
3. Indole-3 acetic acid (IAA) and other closely similar chemicals are the main naturally occurring auxins.
4. Functions of the Auxins:
   1. Facilitate flowering in the plants.
   2. Used in process of plant propagation.
   3. Used by gardeners to keep the lawns free from weeds.
   4. Involved in initiation of roots in stem cuttings.

Gibberellins: -

1. Gibberellins are a class of plant hormones that promote flowering, germination, and stem lengthening.

Cytokinins: -

1. Cytokinins are a class of plant growth regulators that play a key role in cell division in the roots and shoot systems of plants.
2. This hormone supports the cell's development, differentiation, apical dominance, and the postponement of leaf senescence.

Abscisic acid:

1. A growth inhibitor called abscisic was found in the 1960s.
2. It was first referred to as dormant.
3. It is a growth-inhibiting hormone.
4. Abscisic acid causes dormancy in seeds and buds.
5. It promotes the ageing or senescence of leaves and the shedding of leaves.